Interferometric test method for testing convex aspheric mirror surfaces

Size: px
Start display at page:

Download "Interferometric test method for testing convex aspheric mirror surfaces"

Transcription

1 Interferometric test method for testing convex aspheric mirror surfaces T. Stewart McKechnie McKechnie Optics Research, Paganica Way NE, Albuquerque, NM 87111, USA Keywords: Interferometry, interferometric testing, convex aspheric surfaces, surface shape measurement Abstract An interferometric null Test Method is described for testing convex aspheric surfaces, such as found in secondary mirrors of Cassegrain telescopes or variations thereof such as Mersenne and Ritchey-Chrétien. A family of test designs is described covering a wide range of mirror diameters, radii of curvature, and aspheric shapes as described by conic constants and/or polynomials. The Test Method has been used successfully for testing the convex hyperboloid surface of the 244-mm diameter secondary mirror of the NASA 3-meter IRTF telescope. The Test Method is currently being used to test the 120-mm diameter, convex paraboloid secondary mirrors of the Magdalena Ridge Observatory Interferometer (MROI). Test designs exist on paper for both Keck secondary mirrors (0.53-m and 1.4-m diameter), the HST secondary (0.3-meter diameter), and secondary mirrors of some of the extremely large telescopes of the future, such as the TMT secondary (3.2-m diameter). In typical test embodiments, the simplicity of the Test enables rapid implementation at a fraction of the cost of comparable Hindle-Sphere or Hindle-Simpson tests. 1. Introduction Large reflector telescopes are generally Cassegrain or variations thereof such as Mersenne and Ritchey-Chrétien. All share the property of having convex aspheric secondary mirrors: hyperboloid for the Classic Cassegrain and Ritchey- Chrétien, paraboloid for the Mersenne. A widely-used interferometric test for convex aspheric secondary mirrors, including those just mentioned, is the Hindle-Sphere test. Figure 1 shows an improved version of the Hindle-Sphere test, the Hindle-Simpson test 1. This test uses two ancillary optical components. Both have spherical surfaces. One is a meniscus component the Hindle sphere the other a concave calibration mirror. The surfaces of the ancillary optics are figured to high precision. The diameters have to be larger than the diameter of the convex mirror under test. Hindle-Simpson null tests are carried out at the conjugate distances used by the telescope. For large telescope secondaries, these distances can be correspondingly large. A shortening lens is sometimes used (Figure 2) to reduce test track length. The surfaces of the shortening lens must also be figured to high precision; lens diameter again has to be larger than the diameter of the convex mirror under test. The Test Method described in this paper offers an alternative to Hindle-Sphere tests. An embodiment is shown in Figure 3. While the Test Method cannot be used with opaque mirror substrates, the Method has a number of advantages over comparable Hindle-Sphere tests when used with transmissive substrate materials, such as fused silica, Zerodur, Clearceram-Z, and other optical glass types. Experience gained thus far indicates that Test Method embodiments can be built and implemented more rapidly and at a fraction of the cost of comparable Hindle-Sphere tests. To test a medium-sized secondary mirror (say 250-mm diameter) using a Hindle-Sphere test could mean outlays of several-thousand dollars for suitable-sized ancillary optic substrates figured to suitable optical specifications. In comparison, substrate and fabrication costs for the smaller ancillary optics used by the Test Method may amount to just a few hundred dollars. The small size and simple shapes of the ancillary optics (often plano-convex) enable low cost Test setups that are capable of high measurement accuracy. In typical Test implementations, residual null test wavefront error is about λ/100 (HeNe).

2 Figure 1: Hindle-Simpson test - a standard test for surface figure quality of convex aspheric mirrors. Carried out at the optical conjugates of the telescope, the test constitutes a perfect null test. Figure 2: Shortened Hindle-Simpson test, another standard test for convex aspheric mirrors. Figure 3: Test Method embodiment used for testing the 244-mm diameter NASA secondary mirror.

3 2. Test Method Referring again to Figure 3, the Test Method works as follows: Both front and rear surfaces of the convex aspheric secondary mirror under test the Test Optic are polished, thereby transforming the mirror into a lens. The mirror is then tested as if it were a lens by an interferometric null test, prior to applying a reflective coating to the convex mirror surface. Patent applications relating to the Test Method are listed in Section 10. All standard aspheric shapes can be tested using the Test Method, including hyperboloids, paraboloids, and ellipsoids. The Test Method may also be used for testing other more general types of aspheric shape, as described by polynomial equations. The surfaces of the ancillary optics may be either flat or spherical. Test accuracy is matched to requirements. Peak-to-Valley (P-V) wavefront error residuals of the null test are typically about λ/100 (HeNe) but, if needed, can readily be reduced to about λ/1,000 (HeNe). For most purposes, the Test constitutes a perfect null test. 3. Test Method applications In 2009, the convex hyperboloid secondary mirror of the NASA 3-meter Telescope (IRTF, Mauna Kea) was re-figured by Optical Surface Technologies (OST) as part of a telescope optics upgrade program. Secondary mirror surface figure was tested by OST using the Test Method embodiment shown in Figure 3. In its original state, the NASA secondary mirror had P-V surface figure errors of about 1. λ (HeNe) not unusual for telescope optics built in the 1970s. The goal of the secondary mirror upgrade was to reduce this error to λ/8 (HeNe). The Test is currently being used to test the 120-mm diameter convex paraboloid secondary mirrors of the (sixtelescope) Magdalena Ridge Observatory Interferometer. Wider application of the Test Method has been explored through Test designs (on paper) for testing numerous other convex aspheric secondary mirrors. These include both Keck secondaries (0.53-meter and 1.4-meter diameter), the HST secondary (0.3-meter diameter), and the TMT secondary (3.2-meter diameter). In the above applications, the use of uncomplicated in some cases COTS Null Lenses offers the prospect of Test implementations at a fraction of the cost of equivalent Hindle-Sphere tests. The convex surface of the secondary mirror must of course be figured to a precise aspheric shape. There is no similar requirement for the rear surface. This surface may be figured to any convenient shape flat or spherical, convex or concave. Tested as a lens rather than a mirror, the Test Optic introduces significant amounts of spherical aberration, comprising first-order and higher orders. To cancel this aberration, an ancillary lens is used the Null Lens shown in Figure 3. The goal is usually to provide a near-perfect null test, but residual aberrations particularly if only a few waves can be calculated and subtracted, providing a form of null test. There is no obligation to carry out the Test at the optical conjugates used by the telescope. Any convenient conjugate set may be chosen, consistent with providing a practicable Test that delivers required test accuracy. 4. Test Method family An infinite number of Test Method embodiments can be envisaged. The family sub-divides into three main classes, corresponding to the Test geometries shown in Figures 3, 4, and 5. There are many sub-classes and permutations. The different geometries offer a range of measurement sensitivities and choice of Test track lengths. Track length of the Figure 3 embodiment is roughly the same as the focal length, f, of the Test Optic (considered as a lens). For the NASA Zerodur secondary equipped with flat rear surface, f is about 2-meters. Residual null test error for

4 Figure 4: Test embodiment with longer track length (~ 4. f). Residual wavefront error for this type of null test embodiment is usually small (~ λ/1,000). Figure 5: Test embodiment with ultra-short track length. For Test Optic with flat rear surfaces and substrate refractive index ~ 1.5, track length is given roughly by f/3. this Test embodiment corresponds to a P-V surface figure error on the convex mirror surface of about λ/70 (HeNe). Convex mirrors tested as in Figure 4 have Test track lengths of about 4. f, about four times longer than track lengths in Figure 3 embodiments. Generally, increased track length associates with increased test sensitivity. For the NASA secondary tested as in Figure 4, null test residuals correspond to a P-V surface figure error of about λ/2,000 (HeNe). Track lengths in Figure 5 embodiments are generally short, typically about f/3, which means compact Test setups. The Figure 5 arrangement is similar to those proposed in 1983 by Meinel and Meinel 1. For the NASA secondary tested as in Figure 5, null test residuals correspond to a P-V surface figure error of about λ/125 (HeNe). Null Lenses used in the NASA secondary mirror Test embodiments shown in Figures 3, 4, and 5 all have simple plano-convex or planoconcave designs, so that residual surface figure errors, such as the λ/125 just indicated, are useful for cross-comparing test accuracies offered by the different Test geometries. Fold mirrors may be used anywhere in the optical path to shrink Test area footprint. By making the rear surface of the Test Optic convex or concave spherical, Test Optic focal length and hence Test track length can be adjusted. In the Figure 5 Test embodiment, the surface is tested by internal reflection (in contrast to the transmission mode Test embodiments used in Figures 3 and 4). The Figure 5 Test embodiment can provide improved discrimination of surface figure error, the improvement factor being n/(n-1), where n is substrate refractive index. For common substrate materials such as fused silica, Zerodur, and Clearceram-Z, n/(n-1) is about 3. A disadvantage of the Figure 5 Test geometry is that larger amounts of spherical aberration may have to be compensated. To preserve null test accuracy, more complicated Null Lens designs may be necessary, which tends to offset the initial advantage.

5 5. Optical homogeneity requirement for Test Optic Refractive index inhomogeneity in Test Optic substrates can affect Test accuracy. Fused silica, Zerodur, and Clearceram-Z are all available in highest-grade (Grade 5) blanks. All three materials make suitable Test Optic substrates. Inhomogeneity may become more of an issue for larger thicker secondary mirrors. By initially flattening and polishing the front and rear surfaces of the Test Optic, inhomogeneities can be characterized, the characterization used later to correct final surface figure data. 6. Null Lens The Null Lens used for testing the NASA secondary mirror (Figure 3) is a custom plano-convex lens made from highest grade Grade 5 fused silica. Null Lens surface figure accuracy is crucial to overall Test accuracy. By oversizing the Null Lens, P-V surface figure errors of less than λ/100 (HeNe) are readily achieved over clear aperture portions. Null Lenses are often plano-convex. Sometimes they are COTS, facilitating rapid Test implementation. For more challenging Test applications, Null Lenses with aspheric surfaces could be used. But a simpler approach is to use a Null Lens design comprising two (or more) conventional lenses. Null Lens diameters are significantly smaller than Test Optic diameters. For example, a Figure 4 Test embodiment designed for testing the 300-mm diameter HST secondary mirror uses a 25-mm diameter COTS Null Lens. Despite the simplicity and low cost of this particular Null Lens, the Test embodiment delivers λ/1,000 (HeNe) residual null test accuracy. 7. Interferometry (and wavefront sensing) The Test may be carried out at any wavelength transmitted by the substrate. Fused silica, Zerodur, and Clearceram-Z are all transmissive at standard visible test wavelengths, such as 633 nm. UV, IR, and other wavelengths can also be used. The interferometer test beam may be collimated, convergent, or divergent, the latter options provided by transmission spheres. For tests involving longer paths, vibration-insensitive interferometers are desirable. Frequency stabilized lasers have coherence lengths of about 100 meters, sufficient for testing very large several meter diameter convex secondary mirrors, such as found in ELTs. The scope of the paper limits the discussion to interferometric applications. However, the Test Method can be used equally with wavefront sensing techniques, with only minor modifications needed to the Test setups. 8. Relaxing figure requirement on rear surface of Test Optic The rear surface of the Test Optic can be made flat or spherical, concave or convex. If multiple copies of the same Test Optic have to be made, having to figure each individual rear surface to high precision could add significantly to overall production costs. The figure requirement on the rear surface can be significantly reduced by index-matching this surface to a Test Window of good optical quality, as shown in Figure 6. Index-matching liquids are commercially available with refractive indices held to about +/ In a typical index-matching enactment, one surface of the Test Window is figured to high precision, perhaps to λ/20 (HeNe) or better. The other surface the left-hand surface in Figure 6 is figured to lower precision, as discussed below. With Test Window and Test Optic index-matched together, figure requirement for the rear surface of the Test

6 Figure 6: Relaxing surface figure requirement on rear surface of Test Optic by index-matching to a precisely fabricated Test Window. With close enough index-matching (+/ ) a ground or generated finish on the rear surface may be adequate. Optic relaxes by a substantial factor perhaps 1000x to about 10. λ (HeNe). A ground or generated surface may satisfy the relaxed requirement. A similar figure relaxation also occurs in the contacting surface of the Test Window. Test Window cost may be amortized over the number of mirrors (Test Optics) produced. 9. NASA 3-meter telescope secondary mirror Test embodiment Figure 3 shows the double-pass Test setup used for testing the NASA secondary mirror. Figure 7 shows final surface figure achieved. By testing the convex aspheric surface in transmission as in Figure 3, surface figure errors appear 1/(n-1) times smaller than had the test been carried out in reflection. When used on the telescope, the Zerodur NASA secondary (n = 1.54) produces wavefront errors about 1.85x larger than those indicated by Figure 7. Figure 8 (Left) shows a theoretical interferogram for a perfectly-figured NASA secondary mirror. Figure 8 (Right) again shows the NASA mirror, but with distorted fringes caused by a significant conic constant error. Figure 9 shows the theoretical double-pass residual null test wavefront error for the (Figure 3) NASA secondary Test embodiment. Residual wavefront error corresponds to a surface figure error on the mirror of about λ/70 (HeNe). Had a more precise null test been required for the NASA secondary, a Figure 4 embodiment type with λ/2,000 (HeNe) residual error could have been used. For the NASA mirror, however, shorter track length was preferred over what was considered unnecessarily high null test precision. Figure 7: Interferogram showing final surface figure achieved by OST on the refurbished, 244-mm diameter hyperboloid NASA secondary mirror. P-V surface figure error λ/8 HeNe).

7 Figure 8: (Left): Fringe appearance at 633-nm for perfectly-figured 244-mm diameter hyperboloid NASA secondary mirror, tested as in Figure 3. (Right): Fringe appearance for same mirror with significant conic constant error ( instead of ). Figure 9: Theoretical residual null test wavefront error, P-V λ/130 (HeNe), for the NASA secondary mirror, tested as in Figure 3. Wavefront corrugations are barely discernible. Vertical plot scale: +/- λ/2 (HeNe). 10. Patents [1] Test Method for Surface Figure of Large Convex Mirrors. Inventor/Applicant Name: Thomas Stewart McKechnie; Filed Dec 24, 2008; Application Number 12/ [2] Test Method for Surface Figure of Large Convex Mirrors, continuation-in-part of pending Application Number 12/ Inventor/Applicant Name: Thomas Stewart McKechnie; Filed May 17, 2009; Application Number References [1] Malacara, D., (Ed.), [Optical Shop Testing], Second edition, John Wiley & Sons, Inc., (1992).

waves rays Consider rays of light from an object being reflected by a plane mirror (the rays are diverging): mirror object

waves rays Consider rays of light from an object being reflected by a plane mirror (the rays are diverging): mirror object PHYS1000 Optics 1 Optics Light and its interaction with lenses and mirrors. We assume that we can ignore the wave properties of light. waves rays We represent the light as rays, and ignore diffraction.

More information

2) A convex lens is known as a diverging lens and a concave lens is known as a converging lens. Answer: FALSE Diff: 1 Var: 1 Page Ref: Sec.

2) A convex lens is known as a diverging lens and a concave lens is known as a converging lens. Answer: FALSE Diff: 1 Var: 1 Page Ref: Sec. Physics for Scientists and Engineers, 4e (Giancoli) Chapter 33 Lenses and Optical Instruments 33.1 Conceptual Questions 1) State how to draw the three rays for finding the image position due to a thin

More information

Application Report: Running µshape TM on a VF-20 Interferometer

Application Report: Running µshape TM on a VF-20 Interferometer : Running µshape TM on a VF-20 Interferometer General This report describes how a fiber interferometer from Arden Photonics Ltd was used together with the µshape TM Generic software package. The VF-20

More information

Optical Standards. John Nichol BSc MSc

Optical Standards. John Nichol BSc MSc Optical Standards John Nichol BSc MSc The following notes are presented to explain: Spherical Aberration The Airy Disk Peak to Valley, RMS and Strehl Ratio Standards of Optics produced by Nichol Optical

More information

Measuring Miniature Lens Radius of Curvature and Refractive Index with White Light Optical Profiler

Measuring Miniature Lens Radius of Curvature and Refractive Index with White Light Optical Profiler Measuring Miniature Lens Radius of Curvature and Refractive Index with White Light Optical Profiler Introduction For miniature lenses with size of few millimeters or sub-millimeter, it is difficult to

More information

Shrinkage Modeling of Injection Molded Precision Optics

Shrinkage Modeling of Injection Molded Precision Optics Shrinkage Modeling of Injection Molded Precision Optics Jay Udayasankaran*, Nelson E. Claytor, Donald M. Combs, Oscar M. Lechuga, John J. Mader, and Rajesh Mittal Fresnel Technologies, Inc., 101 W. Morningside

More information

Compact and Modular Interferometers

Compact and Modular Interferometers µphase & µshape TM Compact and Modular Interferometers OVERVIEW Contents Page µphase Interferometers 3 Interferometry 4 Fizeau Setup................................................................. 4 Twyman-Green

More information

REPORT DOCUMENTATION PAGE

REPORT DOCUMENTATION PAGE REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions,

More information

Grazing incidence wavefront sensing and verification of X-ray optics performance

Grazing incidence wavefront sensing and verification of X-ray optics performance Grazing incidence wavefront sensing and verification of X-ray optics performance Timo T. Saha, Scott Rohrbach, and William W. Zhang, NASA Goddard Space Flight Center, Greenbelt, Md 20771 Evaluation of

More information

EXPERIMENT 6 OPTICS: FOCAL LENGTH OF A LENS

EXPERIMENT 6 OPTICS: FOCAL LENGTH OF A LENS EXPERIMENT 6 OPTICS: FOCAL LENGTH OF A LENS The following website should be accessed before coming to class. Text reference: pp189-196 Optics Bench a) For convenience of discussion we assume that the light

More information

Efficiency, Dispersion and Straylight Performance Tests of Immersed Gratings for High Resolution Spectroscopy in the Near Infra-red

Efficiency, Dispersion and Straylight Performance Tests of Immersed Gratings for High Resolution Spectroscopy in the Near Infra-red Changing the economics of space Efficiency, Dispersion and Straylight Performance Tests of Immersed Gratings for High Resolution Spectroscopy in the Near Infra-red J. Fernandez-Saldivar 1, F. Culfaz 1,

More information

Opto-Mechanical I/F for ANSYS

Opto-Mechanical I/F for ANSYS Abstract Opto-Mechanical I/F for ANSYS Victor Genberg, Keith Doyle, Gregory Michels Sigmadyne, Inc., 803 West Ave, Rochester, NY 14611 genberg@sigmadyne.com Thermal and structural output from ANSYS is

More information

Chapter 6 Telescopes: Portals of Discovery. How does your eye form an image? Refraction. Example: Refraction at Sunset.

Chapter 6 Telescopes: Portals of Discovery. How does your eye form an image? Refraction. Example: Refraction at Sunset. Chapter 6 Telescopes: Portals of Discovery 6.1 Eyes and Cameras: Everyday Light Sensors Our goals for learning:! How does your eye form an image?! How do we record images? How does your eye form an image?

More information

AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light

AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light AP Physics B Ch. 23 and Ch. 24 Geometric Optics and Wave Nature of Light Name: Period: Date: MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Reflection,

More information

Microlenses immersed in nematic liquid crystal with electrically. controllable focal length

Microlenses immersed in nematic liquid crystal with electrically. controllable focal length Microlenses immersed in nematic liquid crystal with electrically controllable focal length L.G.Commander, S.E. Day, C.H. Chia and D.R.Selviah Dept of Electronic and Electrical Engineering, University College

More information

Lens refractive index measurement based on fiber point-diffraction longitudinal interferometry

Lens refractive index measurement based on fiber point-diffraction longitudinal interferometry Lens refractive index measurement based on fiber point-diffraction longitudinal interferometry Lingfeng Chen, * Xiaofei Guo, and Jinjian Hao School of Optoelectronics, Beijing Institute of Technology,

More information

Lesson 29: Lenses. Double Concave. Double Convex. Planoconcave. Planoconvex. Convex meniscus. Concave meniscus

Lesson 29: Lenses. Double Concave. Double Convex. Planoconcave. Planoconvex. Convex meniscus. Concave meniscus Lesson 29: Lenses Remembering the basics of mirrors puts you half ways towards fully understanding lenses as well. The same sort of rules apply, just with a few modifications. Keep in mind that for an

More information

TECNOTTICA CONSONNI SRL CERTIFIED QUALITY MANAGEMENT SYSTEM COMPANY BY DNV UNI EN ISO 9001:2008

TECNOTTICA CONSONNI SRL CERTIFIED QUALITY MANAGEMENT SYSTEM COMPANY BY DNV UNI EN ISO 9001:2008 TECNOTTICA CONSONNI SRL CERTIFIED QUALITY MANAGEMENT SYSTEM COMPANY BY DNV UNI EN ISO 9001:2008 OUR COMPANY Tecnottica Consonni is an optical manufacturing company specialized since 1957 in the manufacture

More information

The Wide Field Cassegrain: Exploring Solution Space

The Wide Field Cassegrain: Exploring Solution Space The Wide Field Cassegrain: Exploring Solution Space Peter Ceravolo Ceravolo Optical Systems www.ceravolo.com peter@ceravolo.com Abstract This article illustrates the use of an internal aperture stop in

More information

Revision problem. Chapter 18 problem 37 page 612. Suppose you point a pinhole camera at a 15m tall tree that is 75m away.

Revision problem. Chapter 18 problem 37 page 612. Suppose you point a pinhole camera at a 15m tall tree that is 75m away. Revision problem Chapter 18 problem 37 page 612 Suppose you point a pinhole camera at a 15m tall tree that is 75m away. 1 Optical Instruments Thin lens equation Refractive power Cameras The human eye Combining

More information

DOING PHYSICS WITH MATLAB COMPUTATIONAL OPTICS RAYLEIGH-SOMMERFELD DIFFRACTION INTEGRAL OF THE FIRST KIND

DOING PHYSICS WITH MATLAB COMPUTATIONAL OPTICS RAYLEIGH-SOMMERFELD DIFFRACTION INTEGRAL OF THE FIRST KIND DOING PHYSICS WITH MATLAB COMPUTATIONAL OPTICS RAYLEIGH-SOMMERFELD DIFFRACTION INTEGRAL OF THE FIRST KIND THE THREE-DIMENSIONAL DISTRIBUTION OF THE RADIANT FLUX DENSITY AT THE FOCUS OF A CONVERGENCE BEAM

More information

digital quality control fail pass at your fingertips Smart Metrology Solutions.

digital quality control fail pass at your fingertips Smart Metrology Solutions. digital quality control fail pass µphase smartgage The clever innovation in digital metrology by FISBA, which lets you smarten up your quality management and economize your production processes, yet spares

More information

Chapter 36 - Lenses. A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University

Chapter 36 - Lenses. A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University Chapter 36 - Lenses A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University 2007 Objectives: After completing this module, you should be able to: Determine

More information

1051-232 Imaging Systems Laboratory II. Laboratory 4: Basic Lens Design in OSLO April 2 & 4, 2002

1051-232 Imaging Systems Laboratory II. Laboratory 4: Basic Lens Design in OSLO April 2 & 4, 2002 05-232 Imaging Systems Laboratory II Laboratory 4: Basic Lens Design in OSLO April 2 & 4, 2002 Abstract: For designing the optics of an imaging system, one of the main types of tools used today is optical

More information

Optical thickness measurement of substrates using a transmitted wavefront test at two wavelengths to average out multiple reflection errors

Optical thickness measurement of substrates using a transmitted wavefront test at two wavelengths to average out multiple reflection errors Copyright 2002 Society of Photo-Optical Instrumentation Engineers. This paper was published in Proceedings of SPIE and is made available as an electronic reprint with permission of SPIE. One print or electronic

More information

Prototyping to Production

Prototyping to Production White Paper Prototyping to Production Konrad Goffin David Montgomery Cicely Rathmell INTRODUCTION CVI Laser Optics quick turnaround prototype services smooth the transition from prototype to production.

More information

Convex Mirrors. Ray Diagram for Convex Mirror

Convex Mirrors. Ray Diagram for Convex Mirror Convex Mirrors Center of curvature and focal point both located behind mirror The image for a convex mirror is always virtual and upright compared to the object A convex mirror will reflect a set of parallel

More information

Manufacture of 8.4 m off-axis segments: a 1/5 scale demonstration

Manufacture of 8.4 m off-axis segments: a 1/5 scale demonstration Manufacture of 8.4 m off-axis segments: a 1/5 scale demonstration H. M. Martin a, J. H. Burge a,b, B. Cuerden a, S. M. Miller a, B. Smith a, C. Zhao b a Steward Observatory, University of Arizona, Tucson,

More information

First let us consider microscopes. Human eyes are sensitive to radiation having wavelengths between

First let us consider microscopes. Human eyes are sensitive to radiation having wavelengths between Optical Differences Between Telescopes and Microscopes Robert R. Pavlis, Girard, Kansas USA icroscopes and telescopes are optical instruments that are designed to permit observation of objects and details

More information

1. You stand two feet away from a plane mirror. How far is it from you to your image? a. 2.0 ft c. 4.0 ft b. 3.0 ft d. 5.0 ft

1. You stand two feet away from a plane mirror. How far is it from you to your image? a. 2.0 ft c. 4.0 ft b. 3.0 ft d. 5.0 ft Lenses and Mirrors 1. You stand two feet away from a plane mirror. How far is it from you to your image? a. 2.0 ft c. 4.0 ft b. 3.0 ft d. 5.0 ft 2. Which of the following best describes the image from

More information

Rutgers Analytical Physics 750:228, Spring 2016 ( RUPHY228S16 )

Rutgers Analytical Physics 750:228, Spring 2016 ( RUPHY228S16 ) 1 of 13 2/17/2016 5:28 PM Signed in as Weida Wu, Instructor Help Sign Out Rutgers Analytical Physics 750:228, Spring 2016 ( RUPHY228S16 ) My Courses Course Settings University Physics with Modern Physics,

More information

Geometric Optics Converging Lenses and Mirrors Physics Lab IV

Geometric Optics Converging Lenses and Mirrors Physics Lab IV Objective Geometric Optics Converging Lenses and Mirrors Physics Lab IV In this set of lab exercises, the basic properties geometric optics concerning converging lenses and mirrors will be explored. The

More information

Imaging techniques with refractive beam shaping optics

Imaging techniques with refractive beam shaping optics Imaging techniques with refractive beam shaping optics Alexander Laskin, Vadim Laskin AdlOptica GmbH, Rudower Chaussee 29, 12489 Berlin, Germany ABSTRACT Applying of the refractive beam shapers in real

More information

Chapter 17: Light and Image Formation

Chapter 17: Light and Image Formation Chapter 17: Light and Image Formation 1. When light enters a medium with a higher index of refraction it is A. absorbed. B. bent away from the normal. C. bent towards from the normal. D. continues in the

More information

C) D) As object AB is moved from its present position toward the left, the size of the image produced A) decreases B) increases C) remains the same

C) D) As object AB is moved from its present position toward the left, the size of the image produced A) decreases B) increases C) remains the same 1. For a plane mirror, compared to the object distance, the image distance is always A) less B) greater C) the same 2. Which graph best represents the relationship between image distance (di) and object

More information

Holographically corrected microscope with a large working distance (as appears in Applied Optics, Vol. 37, No. 10, 1849-1853, 1 April 1998)

Holographically corrected microscope with a large working distance (as appears in Applied Optics, Vol. 37, No. 10, 1849-1853, 1 April 1998) Holographically corrected microscope with a large working distance (as appears in Applied Optics, Vol. 37, No. 10, 1849-1853, 1 April 1998) Geoff Andersen and R. J. Knize Laser and Optics Research Center

More information

Reflection and Refraction

Reflection and Refraction Equipment Reflection and Refraction Acrylic block set, plane-concave-convex universal mirror, cork board, cork board stand, pins, flashlight, protractor, ruler, mirror worksheet, rectangular block worksheet,

More information

NOVEL FOCUSING OPTICS FOR IR LASERS Paper 1504

NOVEL FOCUSING OPTICS FOR IR LASERS Paper 1504 NOVEL FOCUSING OPTICS FOR IR LASERS Paper 1504 Gary Herrit 1, Alan Hedges 1, Herman Reedy 1 1 II-VI Incorporated, 375 Saxonburg Blvd., Saxonburg, PA, 16056, USA Abstract Traditional focusing optics for

More information

Alignement of a ring cavity laser

Alignement of a ring cavity laser Alignement of a ring cavity laser 1 Introduction This manual describes a procedure to align the cavity of our Ti:Sapphire ring laser and its injection with an Argon-Ion pump laser beam. The setup is shown

More information

IMPROVING MEASUREMENTS BASED ON THE CAT S EYE RETRO- REFLECTION. Katherine Mary Medicus

IMPROVING MEASUREMENTS BASED ON THE CAT S EYE RETRO- REFLECTION. Katherine Mary Medicus IMPROVING MEASUREMENTS BASED ON THE CAT S EYE RETRO- REFLECTION by Katherine Mary Medicus A dissertation submitted to the faculty of The University of North Carolina at Charlotte in partial fulfillment

More information

How to make a Galileian Telescope

How to make a Galileian Telescope How to make a Galileian Telescope I. THE BASICS THE PRINCIPLES OF OPTICS A Galileian telescope uses just two lenses. The objective lens is convergent (plano-convex), the ocular lens is divergent (plano-concave).

More information

1 of 9 2/9/2010 3:38 PM

1 of 9 2/9/2010 3:38 PM 1 of 9 2/9/2010 3:38 PM Chapter 23 Homework Due: 8:00am on Monday, February 8, 2010 Note: To understand how points are awarded, read your instructor's Grading Policy. [Return to Standard Assignment View]

More information

P R E A M B L E. Facilitated workshop problems for class discussion (1.5 hours)

P R E A M B L E. Facilitated workshop problems for class discussion (1.5 hours) INSURANCE SCAM OPTICS - LABORATORY INVESTIGATION P R E A M B L E The original form of the problem is an Experimental Group Research Project, undertaken by students organised into small groups working as

More information

HOMEWORK 4 with Solutions

HOMEWORK 4 with Solutions Winter 996 HOMEWORK 4 with Solutions. ind the image of the object for the single concave mirror system shown in ig. (see next pages for worksheets) by: (a) measuring the radius R and calculating the focal

More information

Lecture Notes for Chapter 34: Images

Lecture Notes for Chapter 34: Images Lecture Notes for hapter 4: Images Disclaimer: These notes are not meant to replace the textbook. Please report any inaccuracies to the professor.. Spherical Reflecting Surfaces Bad News: This subject

More information

EXPERIMENT O-6. Michelson Interferometer. Abstract. References. Pre-Lab

EXPERIMENT O-6. Michelson Interferometer. Abstract. References. Pre-Lab EXPERIMENT O-6 Michelson Interferometer Abstract A Michelson interferometer, constructed by the student, is used to measure the wavelength of He-Ne laser light and the index of refraction of a flat transparent

More information

Optical Metrology. Third Edition. Kjell J. Gasvik Spectra Vision AS, Trondheim, Norway JOHN WILEY & SONS, LTD

Optical Metrology. Third Edition. Kjell J. Gasvik Spectra Vision AS, Trondheim, Norway JOHN WILEY & SONS, LTD 2008 AGI-Information Management Consultants May be used for personal purporses only or by libraries associated to dandelon.com network. Optical Metrology Third Edition Kjell J. Gasvik Spectra Vision AS,

More information

Accuracy of SpotOptics wavefront sensors. June 2010 Version 4.0

Accuracy of SpotOptics wavefront sensors. June 2010 Version 4.0 Accuracy of SpotOptics wavefront sensors June Version 4.0 1 1 Basic concepts: accuracy, precision and repeatability Repeatability is not the same as accuracy You can have high repeatability but low accuracy

More information

Procedure: Geometrical Optics. Theory Refer to your Lab Manual, pages 291 294. Equipment Needed

Procedure: Geometrical Optics. Theory Refer to your Lab Manual, pages 291 294. Equipment Needed Theory Refer to your Lab Manual, pages 291 294. Geometrical Optics Equipment Needed Light Source Ray Table and Base Three-surface Mirror Convex Lens Ruler Optics Bench Cylindrical Lens Concave Lens Rhombus

More information

FTIR Instrumentation

FTIR Instrumentation FTIR Instrumentation Adopted from the FTIR lab instruction by H.-N. Hsieh, New Jersey Institute of Technology: http://www-ec.njit.edu/~hsieh/ene669/ftir.html 1. IR Instrumentation Two types of instrumentation

More information

DEFINING AND MEASURING PHYSICAL PARAMETERS OF PC POLISHED FIBER OPTIC CONNECTORS

DEFINING AND MEASURING PHYSICAL PARAMETERS OF PC POLISHED FIBER OPTIC CONNECTORS DEFINING AND MEASURING PHYSICAL PARAMETERS OF PC POLISHED FIBER OPTIC CONNECTORS Eric A. Norland Norland Products, Inc. PO Box 637, Building100 2540 Route 130 Cranbury, NJ 08512 www.norlandprod.com ABSTRACT

More information

Physics 10. Lecture 29A. "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton

Physics 10. Lecture 29A. There are two ways of spreading light: to be the candle or the mirror that reflects it. --Edith Wharton Physics 10 Lecture 29A "There are two ways of spreading light: to be the candle or the mirror that reflects it." --Edith Wharton Converging Lenses What if we wanted to use refraction to converge parallel

More information

The Evolution of the Optical Zone in Corneal Refractive Surgery. Bruce Drum, Ph.D.

The Evolution of the Optical Zone in Corneal Refractive Surgery. Bruce Drum, Ph.D. The Evolution of the Optical Zone in Corneal Refractive Surgery. Bruce Drum, Ph.D. FDA, Division of Ophthalmic and ENT Devices, Rockville, MD Disclaimer This presentation represents the professional opinion

More information

Introduction to Fourier Transform Infrared Spectrometry

Introduction to Fourier Transform Infrared Spectrometry Introduction to Fourier Transform Infrared Spectrometry What is FT-IR? I N T R O D U C T I O N FT-IR stands for Fourier Transform InfraRed, the preferred method of infrared spectroscopy. In infrared spectroscopy,

More information

Optical System Design

Optical System Design Optical System Design Robert E. Fischer CEO, OPTICS 1, Incorporated Biljana Tadic-Galeb Panavision Paul R. Yoder Consultant With contributions by Ranko Galeb Bernard C.Kress, Ph.D. Stephen C. McClain,

More information

Lecture 17. Image formation Ray tracing Calculation. Lenses Convex Concave. Mirrors Convex Concave. Optical instruments

Lecture 17. Image formation Ray tracing Calculation. Lenses Convex Concave. Mirrors Convex Concave. Optical instruments Lecture 17. Image formation Ray tracing Calculation Lenses Convex Concave Mirrors Convex Concave Optical instruments Image formation Laws of refraction and reflection can be used to explain how lenses

More information

Optical Communications

Optical Communications Optical Communications Telecommunication Engineering School of Engineering University of Rome La Sapienza Rome, Italy 2005-2006 Lecture #2, May 2 2006 The Optical Communication System BLOCK DIAGRAM OF

More information

Study Guide for Exam on Light

Study Guide for Exam on Light Name: Class: Date: Study Guide for Exam on Light Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which portion of the electromagnetic spectrum is used

More information

LIGHT REFLECTION AND REFRACTION

LIGHT REFLECTION AND REFRACTION QUESTION BANK IN SCIENCE CLASS-X (TERM-II) 10 LIGHT REFLECTION AND REFRACTION CONCEPTS To revise the laws of reflection at plane surface and the characteristics of image formed as well as the uses of reflection

More information

3D Printing LESSON PLAN PHYSICS 8,11: OPTICS

3D Printing LESSON PLAN PHYSICS 8,11: OPTICS INVESTIGATE RATIONALE Optics is commonly taught through the use of commercial optics kits that usually include a basic set of 2-4 geometric lenses (such as double convex or double concave). These lenses

More information

RAY OPTICS II 7.1 INTRODUCTION

RAY OPTICS II 7.1 INTRODUCTION 7 RAY OPTICS II 7.1 INTRODUCTION This chapter presents a discussion of more complicated issues in ray optics that builds on and extends the ideas presented in the last chapter (which you must read first!)

More information

Solution Derivations for Capa #14

Solution Derivations for Capa #14 Solution Derivations for Capa #4 ) An image of the moon is focused onto a screen using a converging lens of focal length (f = 34.8 cm). The diameter of the moon is 3.48 0 6 m, and its mean distance from

More information

Optical Design using Fresnel Lenses

Optical Design using Fresnel Lenses Optical Design using Fresnel Lenses Basic principles and some practical examples Arthur Davis and Frank Kühnlenz Reflexite Optical Solutions Business Abstract The fresnel lens can be used in a wide variety

More information

Recommended alignment procedure for Shaper 6_6 / Focal- Shaper 9

Recommended alignment procedure for Shaper 6_6 / Focal- Shaper 9 Recommended alignment procedure for Shaper 6_6 / Focal- Shaper 9 The described below procedure presents an example of alignment of beam shapers Shaper and Focal- Shaper (F- Shaper) with using the standard

More information

Basic Optics System OS-8515C

Basic Optics System OS-8515C 40 50 30 60 20 70 10 80 0 90 80 10 20 70 T 30 60 40 50 50 40 60 30 C 70 20 80 10 90 90 0 80 10 70 20 60 50 40 30 Instruction Manual with Experiment Guide and Teachers Notes 012-09900B Basic Optics System

More information

MEASUREMENT OF END FACE GEOMETRY ON FIBER OPTIC TERMINI...2

MEASUREMENT OF END FACE GEOMETRY ON FIBER OPTIC TERMINI...2 MEASUREMENT OF END FACE GEOMETRY ON FIBER OPTIC TERMINI...2 IMPORTANCE OF END FACE GEOMETRY...2 FIBER OPTIC CONNECTOR END FACE GEOMETRY MEASUREMENT TECHNIQUES...2 INTERFEROMETRIC MICROSCOPE TYPES...3 MEASUREMENT

More information

Chapter 23. The Reflection of Light: Mirrors

Chapter 23. The Reflection of Light: Mirrors Chapter 23 The Reflection of Light: Mirrors Wave Fronts and Rays Defining wave fronts and rays. Consider a sound wave since it is easier to visualize. Shown is a hemispherical view of a sound wave emitted

More information

Aspherical Lens Design by Using a Numerical Analysis

Aspherical Lens Design by Using a Numerical Analysis Journal of the Korean Physical Society, Vol. 51, No. 1, July 27, pp. 93 13 Aspherical Lens Design by Using a Numerical Analysis Gyeong-Il Kweon Department of Optoelectronics, Honam University, Gwangju

More information

Understanding astigmatism Spring 2003

Understanding astigmatism Spring 2003 MAS450/854 Understanding astigmatism Spring 2003 March 9th 2003 Introduction Spherical lens with no astigmatism Crossed cylindrical lenses with astigmatism Horizontal focus Vertical focus Plane of sharpest

More information

ID Objective Requirements Description of Test Date & Examiner 15 Verify that the optics?? OMC

ID Objective Requirements Description of Test Date & Examiner 15 Verify that the optics?? OMC NAOMI OMC/NCU Acceptance Tests at the University of Durham ATC Document number AOW/GEN/RAH/15.0/06/00 OMC/NCU acceptance tests DRAFT (Version date: 2 nd June 2000) wht-naomi-44 The ID numbers are those

More information

Thin Lenses Drawing Ray Diagrams

Thin Lenses Drawing Ray Diagrams Drawing Ray Diagrams Fig. 1a Fig. 1b In this activity we explore how light refracts as it passes through a thin lens. Eyeglasses have been in use since the 13 th century. In 1610 Galileo used two lenses

More information

ENGINEERING METROLOGY

ENGINEERING METROLOGY ENGINEERING METROLOGY ACADEMIC YEAR 92-93, SEMESTER ONE COORDINATE MEASURING MACHINES OPTICAL MEASUREMENT SYSTEMS; DEPARTMENT OF MECHANICAL ENGINEERING ISFAHAN UNIVERSITY OF TECHNOLOGY Coordinate Measuring

More information

Optical laser beam scanner lens relay system

Optical laser beam scanner lens relay system 1. Introduction Optical laser beam scanner lens relay system Laser beam scanning is used most often by far in confocal microscopes. There are many ways by which a laser beam can be scanned across the back

More information

Testing of Aspheric Surfaces with computer Generated Holograms

Testing of Aspheric Surfaces with computer Generated Holograms Testing of Aspheric Surfaces with computer Generated Holograms H.Tiziani, B.PackroB, G.Schmidt Institut fur Technische Optik, Universitat Stuttgart, Pfaffenwaldring 9, 7000 Stuttgart 80, FRG Summary Aspherical

More information

Alignment Laser System.

Alignment Laser System. - O T 6 0 0 0 Alignment Laser System. The OT-6000. Multi -Target,Two Dimensional Alignment. Introducing the most powerful way to measure alignment at distances up to 300 feet. The OT-6000 Alignment Laser

More information

4.3.5: High Temperature Test 3

4.3.5: High Temperature Test 3 temperature and 800 degrees Celsius is made by matching the optical path lengths of the measurement and sensing arms at both temperatures. By marking the relative distance between the GRIN lens and mirror

More information

Teacher s Resource. 2. The student will see the images reversed left to right.

Teacher s Resource. 2. The student will see the images reversed left to right. Answer Booklet Reflection of Light With a Plane (Flat) Mirror Trace a Star Page 16 1. The individual students will complete the activity with varying degrees of difficulty. 2. The student will see the

More information

3.5.4.2 One example: Michelson interferometer

3.5.4.2 One example: Michelson interferometer 3.5.4.2 One example: Michelson interferometer mirror 1 mirror 2 light source 1 2 3 beam splitter 4 object (n object ) interference pattern we either observe fringes of same thickness (parallel light) or

More information

LOCATION DEPENDENCY OF POSITIONING ERROR IN A 3-AXES CNC MILLING MACHINE

LOCATION DEPENDENCY OF POSITIONING ERROR IN A 3-AXES CNC MILLING MACHINE th International & 26 th All India Manufacturing Technology, Design and Research Conference (AIMTDR 214) December 12 th 14 th, 214, IIT Guwahati, Assam, India LOCATION DEPENDENCY OF POSITIONING ERROR IN

More information

Modern Classical Optics

Modern Classical Optics Modern Classical Optics GEOFFREY BROOKER Department of Physics University of Oxford OXPORD UNIVERSITY PRESS Contents 1 Electromagnetism and basic optics 1 1.1 Introduction 1 1.2 The Maxwell equations 1

More information

Realization of a UV fisheye hyperspectral camera

Realization of a UV fisheye hyperspectral camera Realization of a UV fisheye hyperspectral camera Valentina Caricato, Andrea Egidi, Marco Pisani and Massimo Zucco, INRIM Outline Purpose of the instrument Required specs Hyperspectral technique Optical

More information

SafetyScan Lens. User Manual

SafetyScan Lens. User Manual SafetyScan Lens User Manual Contents Introduction 2 Lens selection 3 Beam quality parameter Using the tables Use with lasers whose M 2 is 1.2 4 Use with lasers whose M 2 is 3.0 5 Use with lasers whose

More information

A Guide to Acousto-Optic Modulators

A Guide to Acousto-Optic Modulators A Guide to Acousto-Optic Modulators D. J. McCarron December 7, 2007 1 Introduction Acousto-optic modulators (AOMs) are useful devices which allow the frequency, intensity and direction of a laser beam

More information

Optical Digitizing by ATOS for Press Parts and Tools

Optical Digitizing by ATOS for Press Parts and Tools Optical Digitizing by ATOS for Press Parts and Tools Konstantin Galanulis, Carsten Reich, Jan Thesing, Detlef Winter GOM Gesellschaft für Optische Messtechnik mbh, Mittelweg 7, 38106 Braunschweig, Germany

More information

Application Note #503 Comparing 3D Optical Microscopy Techniques for Metrology Applications

Application Note #503 Comparing 3D Optical Microscopy Techniques for Metrology Applications Screw thread image generated by WLI Steep PSS angles WLI color imaging Application Note #503 Comparing 3D Optical Microscopy Techniques for Metrology Applications 3D optical microscopy is a mainstay metrology

More information

Simplifying Opto- Mechanical Product Development: How a new product reduces cost, stress, and time to market

Simplifying Opto- Mechanical Product Development: How a new product reduces cost, stress, and time to market Simplifying Opto- Mechanical Product Development: How a new product reduces cost, stress, and time to market Innovation in optical design is exploding. From cell phone cameras to space telescopes, driverless

More information

Laboratory #3 Guide: Optical and Electrical Properties of Transparent Conductors -- September 23, 2014

Laboratory #3 Guide: Optical and Electrical Properties of Transparent Conductors -- September 23, 2014 Laboratory #3 Guide: Optical and Electrical Properties of Transparent Conductors -- September 23, 2014 Introduction Following our previous lab exercises, you now have the skills and understanding to control

More information

Telescope. The Hubble. Failure Rewrt. ODtid. November 1930. National Aeronautics and Space Administration

Telescope. The Hubble. Failure Rewrt. ODtid. November 1930. National Aeronautics and Space Administration The Hubble ODtid - Telescope Failure Rewrt November 1930 National Aeronautics and Space Administration Tne Hubble Space Telescope Optical Systems Failure Report November 1W National Aeronautics and Space

More information

ALMA Newsletter. ALMA In-depth. How Will ALMA Make Images? April 2010

ALMA Newsletter. ALMA In-depth. How Will ALMA Make Images? April 2010 How Will ALMA Make Images? Credit: ALMA (ESO / NAOJ / NRAO), Cynthia Collao (ALMA). The invention of the optical telescope by Galileo 400 years ago marked the beginning of modern astronomy. Galileo used

More information

Problem Statement. Focal Point: Spherical aberration in Hubble Space Telescope (HST) images returned from orbit

Problem Statement. Focal Point: Spherical aberration in Hubble Space Telescope (HST) images returned from orbit Root Cause Analysis Report Example_Hubble Space elescope Problem Statement Report umber /A RCA Owner Brian Hughes Report Date 12/7/2015 RCA Facilitator Brian Hughes Focal Point: Spherical aberration in

More information

A NEW LOOK AT RISLEY PRISMS. By Craig Schwarze Senior Systems Engineer OPTRA Inc.

A NEW LOOK AT RISLEY PRISMS. By Craig Schwarze Senior Systems Engineer OPTRA Inc. As seen in Photonics Spectra June 2006: A NEW LOOK AT RISLEY PRISMS By Craig Schwarze Senior Systems Engineer OPTRA Inc. Introduction With laser beams finding more and more applications that require aiming

More information

Light Telescopes. Grade Level: 5. 2-3 class periods (more if in-depth research occurs)

Light Telescopes. Grade Level: 5. 2-3 class periods (more if in-depth research occurs) Light Telescopes Grade Level: 5 Time Required: Suggested TEKS: Science - 5.4 Suggested SCANS Information. Acquires and evaluates information. National Science and Math Standards Science as Inquiry, Earth

More information

RAY TRACING UNIFIED FIELD TRACING

RAY TRACING UNIFIED FIELD TRACING RAY TRACING Start to investigate the performance of your optical system using 3D ray distributions, dot diagrams of ray positions and directions, and optical path length. GEOMETRIC FIELD TRACING Switch

More information

Choosing The Right Optical Design Software

Choosing The Right Optical Design Software White Paper Choosing The Right Optical Design Software January 2014 Author Jay Wilson, CODE V Sales Engineer Introduction As a decision maker responsible for making the right choices for your company s

More information

Interference. Physics 102 Workshop #3. General Instructions

Interference. Physics 102 Workshop #3. General Instructions Interference Physics 102 Workshop #3 Name: Lab Partner(s): Instructor: Time of Workshop: General Instructions Workshop exercises are to be carried out in groups of three. One report per group is due by

More information

Rodenstock Photo Optics

Rodenstock Photo Optics Apo-Sironar-S Apo-Macro-Sironar Apo-Grandagon Grandagon-N Accessories: Center filters Accessories: Focus-Mount Lenses for Analog Professional Photography Even in the age of digital photography, the professional

More information

Telescope Types. 2009 by Keith Beadman

Telescope Types. 2009 by Keith Beadman Telescope Types 2009 by Keith Beadman Table of Contents Introduction...2 Telescope Types...2 Refractor...3 How it works...3 Advantages...3 Disadvantages...3 Best Uses...4 Dobsonian...5 How it works...5

More information

LIGHT SECTION 6-REFRACTION-BENDING LIGHT From Hands on Science by Linda Poore, 2003.

LIGHT SECTION 6-REFRACTION-BENDING LIGHT From Hands on Science by Linda Poore, 2003. LIGHT SECTION 6-REFRACTION-BENDING LIGHT From Hands on Science by Linda Poore, 2003. STANDARDS: Students know an object is seen when light traveling from an object enters our eye. Students will differentiate

More information

Physics 1230: Light and Color

Physics 1230: Light and Color Physics 1230: Light and Color The Eye: Vision variants and Correction http://www.colorado.edu/physics/phys1230 What does 20/20 vision mean? Visual acuity is usually measured with a Snellen chart Snellen

More information

Diffraction of a Circular Aperture

Diffraction of a Circular Aperture Diffraction of a Circular Aperture Diffraction can be understood by considering the wave nature of light. Huygen's principle, illustrated in the image below, states that each point on a propagating wavefront

More information