After-pulse-discarding in single-photon detection to reduce bit errors in quantum key distribution
|
|
- Shannon Garrison
- 7 years ago
- Views:
Transcription
1 After-pulse-discarding in single-photon detection to reduce bit errors in quantum key distribution A. Yoshizawa, R. Kaji and H. Tsuchida National Institute of Advanced Industrial Science and Technology (AIST) 1-1-1, Umezono, Tsukuba-shi, Japan Abstract: We demonstrate fiber-optic quantum key distribution (QKD) at 1 nm using single-photon detectors operating at MHz. Such highspeed single-photon detectors are essential to the realization of efficient QKD. However, after-pulses increase bit errors. In the demonstration, we discard after-pulses by measuring time intervals of detection events. For a fiber length of 1. km, we have achieved a key rate of 17 khz with an error of 2%. 23 Optical Society of America OCIS codes: (27.27) Quantum optics; (6.6) Fiber optics and optical communications References and links 1. N. Gisin, G. Ribordy, W. Tittel and H. Zbinden, Quantum cryptography, Rev. Mod. Phys. 74, (22). 2. P. A. Hiskett, G. Bonfrate, G. S. Buller and P. D. Townsend, Eighty kilometer transmission experiment using an InGaAs/InP SPAD-based quantum cryptography receiver operating at 1. µm, J. Mod. Opt. 48, (21). 3. P. A. Hiskett, J. M. Smith, G. S. Buller and P. D. Townsend, Low-noise single-photon detection at wavelength 1. µm, Electron. Lett. 37, (21). 4. M. Bourennane, A. Karlsson, J. P. Ciscar and M. Mathes, Single-photon counters in the telecommunication wavelength region of 1 nm for quantum information processing, J. Mod. Opt. 48, (21).. D. Stucki, G. Ribordy, A. Stefanov, H. Zbinden, J. G. Rarity and T. Wall, Photon counting for quantum key distribution with Peltier cooled InGaAs/InP APDs, J. Mod. Opt. 48, (21). 6. A. Yoshizawa, R. Kaji and H. Tsuchida, A method of discarding after-pulses in single-photon detection for quantum key distribution, Jpn. J. Appl. Phys. 41, (22). 7. D. Stuchi, N. Gisin, O. Guinnard, G. Ribordy and H. Zbinden, Quantum key distribution over 67 km with a plug & play system, New J. Phys. 4, (22). 8. A. Yoshizawa, R. Kaji and H. Tsuchida, Quantum efficiency evaluation method for gated mode single photon detector, Electron. Lett. 38, (22). 9. C. H. Bennett, Quantum cryptography using any two nonorthogonal states, Phys. Rev. Lett. 68, (1992). 1. D. S. Bethune and W. P. Risk, An autocompensating fiber-optic quantum cryptography system based on polarization splitting of light, IEEE J. Quantum Electron. 36, (2). 11. C. H. Bennett and G. Brassard, Quantum Cryptography: Public Key Distribution and Coin Tossing, in Proc. of IEEE Inter. Conf. on Computers and Signal Processing, Bangalore, India (Institute of Electrical and Electronics Engineers, New York, 1984), pp Introduction Quantum key distribution (QKD) is a technique to share a private key of a random binary sequence between two remote parties, sender and receiver (called Alice and Bob, respectively) by exchanging qubits described by single photons or weak coherent pulses, in order to implement a secure one-time-pad encryption and decryption (for a good review, see [1]). Since any unknown qubit state cannot be perfectly copied, an eavesdropper (Eve) (C) 23 OSA 2 June 23 / Vol. 11, No. 11 / OPTICS EXPRESS 133
2 disturbs the transmitted qubits when extracting information. Its security relies on the laws of quantum mechanics. If a single-mode fiber is used as a quantum channel, the most desirable wavelength for low-loss transmission is 1 nm. Recently, 8-km fiber-optic QKD experiments were reported at 1 nm [2]. The performance of indium-gallium-arsenide (InGaAs) avalanche photodiodes (APDs) is widely investigated for single-photon detection at 1 nm. A common method is referred to as the gated mode, in which the APD is pulsebiased above its breakdown [3-]. During the gate-on time, a photon-induced avalanche can grow into a macroscopic pulse. However, a thermally excited carrier also triggers an avalanche, giving a dark count in detection. Furthermore, carriers are trapped every avalanche and if one emits during the next gate-on times, it can trigger a new avalanche. For 1 nm, this avalanche (after-pulse) is frequently found in detection if the repetition frequency exceeds 1 MHz, resulting in a significant increase of bit errors in QKD [-6]. However, high-speed single-photon detectors are essential to the realization of efficient QKD. Since only traps with an emission lifetime comparable to or longer than a reciprocal of the repetition frequency generate after-pulses, introducing a dead time in detection, during which, following an avalanche, no gates are applied to the APD, is an effective way to reduce bit errors in QKD [7]. In this paper, we demonstrate discarding of after-pulses by measuring time intervals of detection events to reduce bit errors in QKD. In the demonstration, single-photon detectors operating at a repetition frequency of MHz are used. Furthermore, Alice is connected to Bob with two single-mode fibers. One is used as a quantum channel while the other for clock sharing. Such a system removes bit errors related to backscattered photons from the clock pulse. Here, we have achieved a key rate of 17 khz with an error of 2% for a fiber length of 1. km. 2. Single-photon detectors The evaluation method for gated-mode single-photon detectors described here makes it possible to measure the quantum efficiency and the after-pulse probabilities per gate from the same data [8]. Here, only important parts are summarized. To obtain the probability distribution, we measure time intervals of detection events. Let p interval ( t) denote the probability of finding t among those measured. Also, let p after-pulse ( t) denote the (conditional) probability that an after-pulse is observed after t following a previous avalanche. Then, one finds that for each interval t n = n/v with n = 1,2,3 p interval ( t n ) = c( t n )e ( n 1)ηµ [(1 e ηµ ) + p after pulse ( t n )] (1) Here, v is a repetition frequency; η is a quantum efficiency and µ is an average of photons per incoming pulse. The probability of finding no after-pulses within an interval of t n can be written as (n = 2,3,4 ) n 1 c( t n ) =Π k=1 [1 p after pulse ( t n )]. (2) For long intervals such that p after-pulse ( t n ) ~, c( t n ) becomes n-independent, enabling us to determine η from the slope of lnp interval ( t n ). Here, ln stands for natural logarithm. Furthermore, considering that c( t 1 ) = 1, p after-pulse ( t n ) is calculated by substituting the estimated value of η into Eq. (1). In the following, two single-photon detectors (D and D1) operating at v = MHz are evaluated. Figure 1 shows lnp interval ( t n ) of D measured at µ =.1. After-pulses are observed as a nonlinear decrease of the measured data for t n < 1 µs. However, for longer intervals, lnp interval ( t n ) decreases linearly, yielding a quantum efficiency of η = 13%. Figure 2 shows lnp interval ( t n ) of D1 measured at the same value of µ. Figure 3 shows the calculated p after-pulse ( t n ), where solid and open circles correspond to those of D (C) 23 OSA 2 June 23 / Vol. 11, No. 11 / OPTICS EXPRESS 134
3 and D1, respectively. Although they have different probabilities for t n < 4 µs, each afterpulse is mostly found within 1 µs following a previous avalanche. Table 1 summarizes operating conditions and evaluation results of D and D1. Here, d thermal and d after-pulse are darkcount probabilities per gate resulting from thermally excited carriers and after-pulses, respectively. The former is evaluated after excluding after-pulses by measuring time intervals of dark counts and discarding those with t n < 1 µs (= t after-puse ). The remaining dark counts are found with a probability of d thermal exp(-d thermal v t after-pulse ), which becomes nearly equal to d thermal if d thermal v t after-pulse << 1. Then, the difference between the dark-count probabilities per gate with and without discarding after-pulses coincides with d after-pulse Non-linear decrease - In p interval η = 13% Interval t (µs) n Fig. 1. ln p interval ( t n ) of D Non-linear decrease - In p interval η = 11% Interval t (µs) n Fig. 2. ln p interval ( t n ) of D1. (C) 23 OSA 2 June 23 / Vol. 11, No. 11 / OPTICS EXPRESS 13
4 Table 1. Operating conditions and evaluation results of single-photon detectors D D1 η 13% 11% d thermal d after-pulse Gate time 1.6 ns Temperature 243 K.3.2 D D1.2 p after-pulse Interval t (µs) n Fig. 3. p after-pulse versus t n. 3. Quantum key distribution 3.1 Quantum channel Figure 4 shows a schematic diagram of the system employed for the QKD demonstration (Bennett s two-coherent-protocol: B92 [9]). Alice is connected to Bob with two 1.-km dispersion-shifted single-mode fibers (DSF1 and DSF2) with a loss of.21 db/km. DSF1 is a quantum channel while DSF2 is used for clock sharing. Here, only the system related to the quantum channel is explained. A gain-switched laser diode (LD1) produces a sequence of light pulses at a repetition frequency of MHz, each having a width of ps with a bandwidth of 1 nm centered at 1 nm. With a polarization controller (PC), the polarization state is aligned for transmission through a polarizing beam splitter (PBS1). With a half-wave plate (HWP) and PBS2, the pulse is divided into signal and reference pulses. After transmission through a quarter-wave plate (QWP) and reflection by a mirror (M), the reference pulse leaves Bob, going to Alice ahead of the signal pulse. With a fiber-optic delay line (DL) and a Faraday rotator mirror (FRM), the signal pulse is delayed for 1 ns compared with the reference pulse. Due to birefringence fluctuations in DSF1, both polarization states become unknown when arriving at Alice. With a polarization-independent phase modulator (PM) [1], Alice modulates the signal pulse at random but evenly between and π while letting the reference pulse unchanged. Alice s FRM guarantees that Bob receives the signal and reference pulses with polarization states linear but orthogonal to their initial states [7, 1]. A pseudo-random number generator (PRNG) outputs a voltage pulse with a width of ns, which is applied to PM only when the bit value is 1. Alice returns the signal and reference pulses to Bob after attenuating those pulses with an attenuator (AT) such that the signal pulse has an average of. photons. At Bob, the reference pulse is delayed compared with the (C) 23 OSA 2 June 23 / Vol. 11, No. 11 / OPTICS EXPRESS 136
5 signal pulse, both re-arriving at PBS2 simultaneously with identical intensity. The recombined pulse is horizontally or vertically polarized, which only reflects Alice s phase choice. The private key can be established by interpreting single-photon detectors D and D1 as and 1, respectively 3.2 Clock sharing Figure 4 also shows how to share the clock between Alice and Bob. A gain-switched laser diode (LD2) produces a sequence of light pulses at a repetition frequency of 1 MHz, each having a width of ps with a bandwidth of 1 nm centered at 1 nm. To synchronize LD1 with LD2, a two-channel synthesized function generator (SFG) is used, which also triggers a delay generator (DG) whose outputs become timing signals for gated-mode operation of D and D1. Alice detects clock pulses sent by Bob via DSF2 with a conventional avalanche photodiode (C-APD), whose output pulse is converted into a square wave with a frequency of 1 MHz, which becomes a reference signal of a frequency synthesizer (FS). A sinusoidal wave with a frequency of 1 MHz is generated from FS, and is applied as a time-base signal to an arbitrary wave function generator, which is used as PRNG. Since the signal/reference pulse and the clock pulse are transmitted through separate fibers, the difference in temperature between DSF1 and DSF2 will cause the relative temporal walk-off between those pulses. However, such a walk-off is estimated to be ~.6 ns/k [2], and is not a significant problem because it is much smaller than the width of the voltage pulse applied to PM (= ns). Compared with the signal and reference pulses, the clock pulse is strong enough to produce a large number of backscattered photons. The presented system prevents those photons from entering single-photon detectors. Thus, only half of backscattered photons from the signal and reference pulses (much weaker than the clock pulse) become bit errors in QKD. DL FRM PBS2 Bob DSF1 Alice M QWP HWP AT PM PBS1 Circulator D1 DG D LD2 SFG DSF2 C-APD FS FRM PRNG PC LD1 Fig. 4. Experimental setup for quantum key distribution. LD1 and LD2: gain-switched laser diodes, PC: polarization controller, PBS1 and PBS2: polarizing beam splitters, HWP: halfwave plate, QWP: quarter-wave plate, M: mirror, DL: delay line, FRM: Faraday rotator mirror, D and D1: single-photon detectors, SFG: synthesized function generator, DG: delay generator, PM: phase modulator, C-APD: conventional avalanche photodiode, PRNG: pseudo-random number generator, AT: attenuator, DSF1 and DSF2: dispersion-shifted single-mode fibers, FS: frequency synthesizer. 4. Results and discussion Figure shows the quantum bit-error rate (QBER) of D after discarding detection events with intervals t n < t discard. Solid circles are the measured results while open circles are corresponding key rates. For t discard < µs, after-pulses are effectively discarded, leading to a (C) 23 OSA 2 June 23 / Vol. 11, No. 11 / OPTICS EXPRESS 137
6 significant decrease in QBER. However, if t discard exceeds µs, the QBER slowly decreases and then becomes t discard -independent. Meanwhile, the key rate shows an exponential decrease such that r = kv exp( kv t discard ). (3) Here, k = ηµexp[-(αl+β)/1]. Note that η is a quantum efficiency of Bob s single-photon detector (D) whereas µ is an average of photons of the signal pulse measured by Alice. α is a fiber loss in db/km; L is a fiber length (km) and β is an internal loss (db) of Bob s system. In the demonstration, η = 13%, µ =., α =.21, L = 1. and β = 3. A curve in Fig. is obtained by substituting those parameters into Eq. (3). Figure 6 shows the measured results corresponding to D1. A curve in this figure is also obtained by substituting the same parameters as D except that η = 11% into Eq. (3). Approximately, the QBER can be written as 1 D µs Exponential Quantum bit-error rate (%) 1 1 Key rate (khz) t (µs) discard Fig.. Measured and calculated quantum bit-error rates (solid circles and open squares, respectively) and corresponding key rates (open circles) of D. (C) 23 OSA 2 June 23 / Vol. 11, No. 11 / OPTICS EXPRESS 138
7 1 D1 1 Quantum bit-error rate (%) 1 µs Exponential 1 Key rate (khz) t (µs) discard Fig. 6. Measured and calculated quantum bit-error rates (solid circles and open squares, respectively) and corresponding key rates (open circles) of D1. e qber ~ d thermal + 1 1/k p after pulse ( t discard + t n ) + e others. (4) 2k 2 n=1 In this equation, the first and second terms on the right-hand side express contributions to bit errors of thermally excited carriers and after-pulses, respectively. In the following calculation, we assume that p after-pulse ~ for t n > 1 µs whereas others are presented as solid and open circles in Fig. 3. The third term on the right-hand side of this equation is the QBER induced by backscattered photons from the signal and reference pulses in the quantum channel, internal reflections at Bob s system and other imperfections of optical and electrical components. In the demonstration, e others ~ 1% and is independent of t discard. Open squares in Figs. and 6 are those calculated with Eq. (4), agreeing with the results obtained in QKD experiments (solid circles). Since the key rate decreases with t discard, we have to properly determine t discard for D and D1. For example, if we choose t discard = 7.6 µs for D and µs for D1, respectively, the total key rate becomes 17 khz with an error of 2%. It is well known that Benett-Brassard-84 protocol (BB84) [11] is the most popular protocol and is more secure than the demonstrated B92 protocol. However, since the systems of two protocols are so similar, the demonstrated discarding method seems to be effective for both protocols to reduce bit errors in QKD. We are planning to increase the repetition frequency of the single-photon detectors for realizing more efficient QKD although afterpulses are more often found in detection. In the demonstration, the sender is connected to the receiver with two single-mode fibers. One is a quantum channel and the other is used for carrying strong clock pulses. In this case, it is important to consider what new strategies could be applied by Eve and see how those strategies influence the security of the QKD. Studying such a security problem will be necessary in the future.. Summary We have demonstrated fiber-optic quantum key distribution at 1 nm using single-photon detectors operating at MHz. After-pulses are discarded by measuring time intervals of detection events, leading to a significant reduction of the quantum bit-error rate. For a fiber length of 1. km, we have achieved a key rate of 17 khz with an error of 2%. (C) 23 OSA 2 June 23 / Vol. 11, No. 11 / OPTICS EXPRESS 139
A High Speed Quantum Communication Testbed
A High Speed Communication Testbed Carl J. Williams, Xiao Tang, Mikko Hiekkero, Julie Rouzaud, Richang Lu, Andreas Goedecke, Alan Migdall, Alan Mink, Anastase Nakassis, Leticia Pibida, Jesse Wen a, Edward
More informationReal-time monitoring of single-photon detectors against eavesdropping in quantum key distribution systems
Real-time monitoring of single-photon detectors against eavesdropping in quantum key distribution systems Thiago Ferreira da Silva, 1,2,* Guilherme B. Xavier, 3,4,5 Guilherme P. Temporão, 1 and Jean Pierre
More informationA Probabilistic Quantum Key Transfer Protocol
A Probabilistic Quantum Key Transfer Protocol Abhishek Parakh Nebraska University Center for Information Assurance University of Nebraska at Omaha Omaha, NE 6818 Email: aparakh@unomaha.edu August 9, 01
More informationSimulation and Best Design of an Optical Single Channel in Optical Communication Network
International Arab Journal of e-technology, Vol., No., June 11 91 Simulation and Best Design of an Optical Single Channel in Optical Communication Network Salah Alabady Computer Engineering Department,
More informationA More Efficient Way to De-shelve 137 Ba +
A More Efficient Way to De-shelve 137 Ba + Abstract: Andrea Katz Trinity University UW REU 2010 In order to increase the efficiency and reliability of de-shelving barium ions, an infrared laser beam was
More informationProposed experiment to test the non-locality hypothesis in transient light-interference phenomena
Proposed experiment to test the non-locality hypothesis in transient light-interference phenomena Masanori Sato Honda Electronics Co., Ltd., 20 Oyamazuka, Oiwa-cho, Toyohashi, Aichi 441-3193, Japan Abstract
More informationFour Wave Mixing in Closely Spaced DWDM Optical Channels
544 VOL. 1, NO. 2, AUGUST 2006 Four Wave Mixing in Closely Spaced DWDM Optical Channels Moncef Tayahi *, Sivakumar Lanka, and Banmali Rawat Advanced Photonics Research lab, Department of Electrical Engineering
More informationThe New Approach of Quantum Cryptography in Network Security
The New Approach of Quantum Cryptography in Network Security Avanindra Kumar Lal 1, Anju Rani 2, Dr. Shalini Sharma 3 (Avanindra kumar) Abstract There are multiple encryption techniques at present time
More informationIncoherent beam combining using stimulated Brillouin scattering in multimode fibers
Incoherent beam combining using stimulated Brillouin scattering in multimode fibers Timothy H. Russell and Won B. Roh Air Force Institute of Technology, Wright-Patterson AFB, Ohio 45433 timothy.russell@afit.edu;
More informationModule 13 : Measurements on Fiber Optic Systems
Module 13 : Measurements on Fiber Optic Systems Lecture : Measurements on Fiber Optic Systems Objectives In this lecture you will learn the following Measurements on Fiber Optic Systems Attenuation (Loss)
More informationDesigning Fiber Optic Systems David Strachan
Designing Fiber Optic Systems David Strachan Everyone knows that fiber optics can carry a huge amount of data. There are more benefits to using fiber optics in broadcast applications than you might realize.
More informationAvalanche Photodiodes: A User's Guide
!"#$%& Abstract Avalanche Photodiodes: A User's Guide Avalanche photodiode detectors have and will continue to be used in many diverse applications such as laser range finders and photon correlation studies.
More informationQuantum Key Distribution as a Next-Generation Cryptographic Protocol. Andrew Campbell
Quantum Key Distribution as a Next-Generation Cryptographic Protocol Andrew Campbell Abstract Promising advances in the field of quantum computing indicate a growing threat to cryptographic protocols based
More informationOptical Fibres. Introduction. Safety precautions. For your safety. For the safety of the apparatus
Please do not remove this manual from from the lab. It is available at www.cm.ph.bham.ac.uk/y2lab Optics Introduction Optical fibres are widely used for transmitting data at high speeds. In this experiment,
More information24 th IEEE Annual Computer Communications Workshop (CCW)
24 th IEEE Annual Computer Communications Workshop (CCW) Exploration of Quantum Cryptography in Network Security Presented by Mehrdad S. Sharbaf Sharbaf & Associates Loyola Marymount University California
More informationarxiv:1403.3122v1 [quant-ph] 12 Mar 2014
Relativistic Quantum Cryptography I. V. Radchenko and K. S. Kravtsov A.. Prokhorov General Physics Institute RAS, oscow, Russia S. P. Kulik Faculty of Physics, oscow State University, oscow, Russia S.
More informationAN1200.04. Application Note: FCC Regulations for ISM Band Devices: 902-928 MHz. FCC Regulations for ISM Band Devices: 902-928 MHz
AN1200.04 Application Note: FCC Regulations for ISM Band Devices: Copyright Semtech 2006 1 of 15 www.semtech.com 1 Table of Contents 1 Table of Contents...2 1.1 Index of Figures...2 1.2 Index of Tables...2
More informationProgress Toward Quantum Communications Networks: Opportunities and Challenges
Progress Toward Quantum Communications Networks: Opportunities and Challenges Robert J. Runser *a,b, Thomas Chapuran a, Paul Toliver a, Nicholas A. Peters a, Matthew S. Goodman a, Jon T. Kosloski b, Nnake
More informationExperiment 5. Lasers and laser mode structure
Northeastern University, PHYS5318 Spring 2014, 1 1. Introduction Experiment 5. Lasers and laser mode structure The laser is a very important optical tool that has found widespread use in science and industry,
More informationSingle Photon Counting Module COUNT -Series
Description Laser Components COUNT series of s has been developed to offer a unique combination of high photon detection efficiency, wide dynamic range and ease of use for photon counting applications.
More informationEvolution and Prospect of Single-Photon
S. Cova, M. Ghioni, A. Lotito, F. Zappa Evolution and Prospect of Single-Photon Avalanche Diodes and Quenching Circuits Politecnico di Milano, Dip. Elettronica e Informazione, Milano, Italy Outline Introduction
More informationModeling and Performance Analysis of DWDM Based 100 Gbps Low Power Inter-satellite Optical Wireless Communication (LP-IsOWC) System
ISSN(Print): 2377-0538 ISSN(Online): 2377-0546 DOI: 10.15764/STSP.2015.01001 Volume 2, Number 1, January 2015 SOP TRANSACTIONS ON SIGNAL PROCESSING Modeling and Performance Analysis of DWDM Based 100 Gbps
More informationA Laser Scanner Chip Set for Accurate Perception Systems
A Laser Scanner Chip Set for Accurate Perception Systems 313 A Laser Scanner Chip Set for Accurate Perception Systems S. Kurtti, J.-P. Jansson, J. Kostamovaara, University of Oulu Abstract This paper presents
More informationHigh-speed transparent switch via frequency upconversion
High-speed transparent switch via frequency upconversion Aaron P. VanDevender and Paul G. Kwiat Department of Physics, University of Illinois at Urbana-Champaign 1110 W Green St., Urbana, IL, 61801 vandvndr@uiuc.edu
More informationFIBER OPTIC COMMUNICATIONS. Optical Fibers
FIBER OPTIC COMMUNICATIONS Optical Fibers Fiber optics (optical fibers) are long, thin strands of very pure glass about the size of a human hair. They are arranged in bundles called optical cables and
More informationA 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 informationIntroduction to Optical Link Design
University of Cyprus Πανεπιστήµιο Κύπρου 1 Introduction to Optical Link Design Stavros Iezekiel Department of Electrical and Computer Engineering University of Cyprus HMY 445 Lecture 08 Fall Semester 2014
More informationÉcole Supérieure d'optique
Conference on Education and Training in Optics & Photonics Marseille, 27 th October 2005 An Optical Time Domain Reflectometry Set-Up for Laboratory Work at École Supérieure d'optique École Supérieure d'optique
More informationImproving Chromatic Dispersion and PMD Measurement Accuracy
Improving Chromatic Dispersion and PMD Measurement Accuracy White Paper Michael Kelly Agilent Technologies Signal transmission over optical fibers relies on preserving the waveform from transmitter to
More informationSimulation of Gaussian Pulses Propagation Through Single Mode Optical Fiber Using MATLAB . MATLAB
Iraqi Journal of Science, 213, Vol.4, No.3, pp.61-66 Simulation of Gaussian Pulses Propagation Through Single Mode Optical Fiber Using MATLAB Salah Al Deen Adnan Taha *, Mehdi M. Shellal, and Ahmed Chyad
More informationDuobinary Modulation For Optical Systems
Introduction Duobinary Modulation For Optical Systems Hari Shanar Inphi Corporation Optical systems by and large use NRZ modulation. While NRZ modulation is suitable for long haul systems in which the
More informationA receiver TDC chip set for accurate pulsed time-of-flight laser ranging
A receiver TDC chip set for accurate pulsed time-of-flight laser ranging Juha Kostamovaara, Sami Kurtti, Jussi-Pekka Jansson University of Oulu, Department of Electrical Engineering, Electronics Laboratory,
More information10 Gb/s all-optical boolean XOR with SOA fiber Sagnac gate
10 Gb/s all-optical boolean XOR with SOA fiber Sagnac gate T. Houbavlis (1), K. Zoiros (1), A. Hatziefremidis (1), H. Avramopoulos (1), L. Occhi (2), G. Guekos (2), S. Hansmann (3), H. Burkhard (3) and
More informationPUMPED Nd:YAG LASER. Last Revision: August 21, 2007
PUMPED Nd:YAG LASER Last Revision: August 21, 2007 QUESTION TO BE INVESTIGATED: How can an efficient atomic transition laser be constructed and characterized? INTRODUCTION: This lab exercise will allow
More informationAnalysis and Improvement of Mach Zehnder Modulator Linearity Performance for Chirped and Tunable Optical Carriers
886 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 20, NO. 5, MAY 2002 Analysis and Improvement of Mach Zehnder Modulator Linearity Performance for Chirped and Tunable Optical Carriers S. Dubovitsky, Member, IEEE,
More informationFibre Bragg Grating Sensors An Introduction to Bragg gratings and interrogation techniques
Fibre Bragg Grating Sensors An ntroduction to Bragg gratings and interrogation techniques Dr Crispin Doyle Senior Applications Engineer, Smart Fibres Ltd. 2003 1) The Fibre Bragg Grating (FBG) There are
More informationDifferential-phase-shift quantum key distribution using heralded narrow-band single photons
Differential-phase-shift quantum key distribution using heralded narrow-band single photons Chang Liu, 1 Shanchao Zhang, 1 Luwei Zhao, 1 Peng Chen, 1 C. -H. F. Fung, 2 H. F. Chau, 2 M. M. T. Loy, 1 and
More informationDevelopment of Optical Wave Microphone Measuring Sound Waves with No Diaphragm
Progress In Electromagnetics Research Symposium Proceedings, Taipei, March 5 8, 3 359 Development of Optical Wave Microphone Measuring Sound Waves with No Diaphragm Yoshito Sonoda, Takashi Samatsu, and
More informationJOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 22, NO. 2, FEBRUARY 2004 1
JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 22, NO. 2, FEBRUARY 2004 1 Photon-Counting OTDR for Local Birefringence and Fault Analysis in the Metro Environment M. Wegmuller, F. Scholder, and N. Gisin Abstract
More information(Amplifying) Photo Detectors: Avalanche Photodiodes Silicon Photomultiplier
(Amplifying) Photo Detectors: Avalanche Photodiodes Silicon Photomultiplier (no PiN and pinned Diodes) Peter Fischer P. Fischer, ziti, Uni Heidelberg, Seite 1 Overview Reminder: Classical Photomultiplier
More informationA PC-BASED TIME INTERVAL COUNTER WITH 200 PS RESOLUTION
35'th Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting San Diego, December 2-4, 2003 A PC-BASED TIME INTERVAL COUNTER WITH 200 PS RESOLUTION Józef Kalisz and Ryszard Szplet
More informationE190Q Lecture 5 Autonomous Robot Navigation
E190Q Lecture 5 Autonomous Robot Navigation Instructor: Chris Clark Semester: Spring 2014 1 Figures courtesy of Siegwart & Nourbakhsh Control Structures Planning Based Control Prior Knowledge Operator
More informationLab 9: The Acousto-Optic Effect
Lab 9: The Acousto-Optic Effect Incoming Laser Beam Travelling Acoustic Wave (longitudinal wave) O A 1st order diffracted laser beam A 1 Introduction qb d O 2qb rarefractions compressions Refer to Appendix
More informationDIRECTIONAL FIBER OPTIC POWER MONITORS (TAPS/PHOTODIODES)
Features: DIRECTIONAL FIBER OPTIC POWER MONITORS (TAPS/PHOTODIODES) PATENT NUMBERS: CANADA 2,494,133, USA 7095931, 7295731 AND CHINA 1672073 Telcordia GR-468 qualified Available in versions for any wavelength
More informationQuantum cryptography
Quantum cryptography Optical fibers to carry information 10 Kb/s 1Tb/s 10 12 b/s Optical fibers vs electrical cables Frequency: 10 8 Hz vs 10 15 Hz Bit rate for electrical interconnections B B 0 A l 2
More informationInterferometric Measurement of Dispersion in Optical Components
Interferometric Measurement of Dispersion in Optical Components Mark Froggatt, Eric Moore, and Matthew Wolfe Luna Technologies, Incorporated, 293-A Commerce Street, Blacksburg, Virginia 246 froggattm@lunatechnologies.com.
More informationQUANTUM LIGHT :! A BRIEF INTRODUCTION!
Quantum Physics QUANTUM LIGHT : A BRIEF INTRODUCTION Philippe Grangier Laboratoire Charles Fabry de l'institut d'optique, UMR 85 du CNRS, 927 Palaiseau, France Quantum Physics * Alain Aspect, in «Demain
More informationISTITUTO NAZIONALE DI FISICA NUCLEARE
ISTITUTO NAZIONALE DI FISICA NUCLEARE Sezione di Catania INFN/TC-11/02 February 28, 2011 PRELIMINARY TESTS OF A SCINTILLATOR-BASED MINI-STATION FOR EXTENSIVE AIR SHOWERS MEASUREMENTS S.Aiola 1, P. La Rocca
More informationProjects. Objective To gain hands-on design and measurement experience with real-world applications. Contents
Projects Contents 9-1 INTRODUCTION...................... 43 9-2 PROJECTS......................... 43 9-2.1 Alarm Radar Sensor................ 43 9-2.2 Microwave FM Communication Link....... 46 9-2.3 Optical
More informationBandwidth analysis of multimode fiber passive optical networks (PONs)
Optica Applicata, Vol. XXXIX, No. 2, 2009 Bandwidth analysis of multimode fiber passive optical networks (PONs) GRZEGORZ STEPNIAK *, LUKASZ MAKSYMIUK, JERZY SIUZDAK Institute of Telecommunications, Warsaw
More informationFast optical source for quantum key distribution based on semiconductor optical amplifiers
Fast optical source for quantum key distribution based on semiconductor optical amplifiers M. Jofre, 1, A. Gardelein, 1 G. Anzolin, 1 W. Amaya, 2 J. Capmany, 2 R. Ursin, 3,4,L.Peñate, 5 D. Lopez, 5 J.
More informationMultiplexing. Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single physical medium.
Multiplexing Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single physical medium. The following two factors in data communications lead to
More informationNuclear Magnetic Resonance
Nuclear Magnetic Resonance Practical Course M I. Physikalisches Institut Universität zu Köln May 15, 2014 Abstract Nuclear magnetic resonance (NMR) techniques are widely used in physics, chemistry, and
More informationAMPLIFIED HIGH SPEED FIBER PHOTODETECTOR USER S GUIDE
AMPLIFIED HIGH SPEED FIBER PHOTODETECTOR USER S GUIDE Thank you for purchasing your Amplified High Speed Fiber Photodetector. This user s guide will help answer any questions you may have regarding the
More informationALMA Memo No. 519 An alternative scheme of round-trip phase correction
ALMA Memo No. 519 An alternative scheme of round-trip phase correction Hitoshi KIUCHIa and Masoto ISHIGUROa anational Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan, hitoshi.kiuchi@nao.ac.jp,
More informationApplication of Quantum Cryptography to an Eavesdropping Detectable Data Transmission
Title Application of Quantum Cryptography Detectable Data Transmission Author(s) Kudo, Takamitsu; Usuda, Tsuyoshi Sa Masayasu IEICE Transactions on Fundamentals Citation Communications and Computer Science
More informationCabling & Test Considerations for 10 Gigabit Ethernet LAN
Introduction Current communication data rates in local networks range from 10/100 megabits per second (Mbps) in Ethernet to 1 gigabit per second (Gbps) in fiber distributed data interface (FDDI) and Gigabit
More informationNumeric modeling of synchronous laser pulsing and voltage pulsing field evaporation
Numeric modeling of synchronous laser pulsing and voltage pulsing field evaporation L. ZHAO 1, A. NORMAND, J. HOUARD, I. BLUM, F. DELAROCHE, F. VURPILLOT Normandie Univ, UNIROUEN, INSA Rouen, CNRS, GPM,
More informationQuantum Cryptography: Privacy Through Uncertainty (Released October 2002) by Salvatore Vittorio
Quantum Cryptography: Privacy Through Uncertainty (Released October 2002) by Salvatore Vittorio Review Key Citations Web Sites Glossary Conferences Editor Review Article 1. Cryptography - an Overview I
More informationOPTICAL FIBERS INTRODUCTION
OPTICAL FIBERS References: J. Hecht: Understanding Fiber Optics, Ch. 1-3, Prentice Hall N.J. 1999 D. R. Goff: Fiber Optic Reference Guide (2 nd ed.) Focal Press 1999 Projects in Fiber Optics (Applications
More informationInternational Journal of Advanced Research in Computer Science and Software Engineering
ISSN: 2277 128X International Journal of Advanced Research in Computer Science and Software Engineering Research Paper Available online at: Key Distillation Process on Quantum Cryptography Protocols in
More informationBroadband THz Generation from Photoconductive Antenna
Progress In Electromagnetics Research Symposium 2005, Hangzhou, China, August 22-26 331 Broadband THz Generation from Photoconductive Antenna Qing Chang 1, Dongxiao Yang 1,2, and Liang Wang 1 1 Zhejiang
More informationQuantum Key Distribution Protocols: A Review
IOSR Journal of Computer Engineering (IOSR-JCE) e-issn: 2278-0661, p- ISSN: 2278-8727Volume 16, Issue 2, Ver. XI (Mar-Apr. 2014), PP 01-09 Quantum Key Distribution Protocols: A Review Hitesh Singh 1, D.L.
More informationEE4367 Telecom. Switching & Transmission. Prof. Murat Torlak
FIBER OPTIC COMMUNICATIONS Optical Fibers Fiber optics (optical fibers) are long, thin strands of very pure glass about the size of a human hair. They are arranged in bundles called optical cables and
More informationScientific Exchange Program
Scientific Exchange Program Electrical characterization of photon detectors based on acoustic charge transport Dr. Paulo Santos, Paul Drude Institute, Berlin,Germany Dr. Pablo Diniz Batista, Brazilian
More informationExperiment # 9. Clock generator circuits & Counters. Eng. Waleed Y. Mousa
Experiment # 9 Clock generator circuits & Counters Eng. Waleed Y. Mousa 1. Objectives: 1. Understanding the principles and construction of Clock generator. 2. To be familiar with clock pulse generation
More informationAPSYN420A/B Specification 1.24. 0.65-20.0 GHz Low Phase Noise Synthesizer
APSYN420A/B Specification 1.24 0.65-20.0 GHz Low Phase Noise Synthesizer 1 Introduction The APSYN420 is a wideband low phase-noise synthesizer operating from 0.65 to 20 GHz. The nominal output power is
More informationA wave lab inside a coaxial cable
INSTITUTE OF PHYSICS PUBLISHING Eur. J. Phys. 25 (2004) 581 591 EUROPEAN JOURNAL OF PHYSICS PII: S0143-0807(04)76273-X A wave lab inside a coaxial cable JoãoMSerra,MiguelCBrito,JMaiaAlves and A M Vallera
More informationarxiv:1306.4174v1 [cs.cr] 18 Jun 2013
arxiv:1306.4174v1 [cs.cr] 18 Jun 2013 Physical-layer encryption on the public internet: a stochastic approach to the Kish-Sethuraman cipher Lachlan J. Gunn James M. Chappell Andrew Allison Derek Abbott
More informationQuantum Cryptography: The Ultimate Solution to Secure Data Transmission?
Quantum Cryptography: The Ultimate Solution to Secure Data Transmission? Ioannis P. Antoniades 1, Amalia N. Miliou 2, Miltiades K. Hatalis 3 1 Department of Informatics, Aristotle University of Thessaloniki,
More informationFiber Optics: Engineering from Global to Nanometer Dimensions
Fiber Optics: Engineering from Global to Nanometer Dimensions Prof. Craig Armiento Fall 2003 1 Optical Fiber Communications What is it? Transmission of information using light over an optical fiber Why
More information# 2. Selecting and Using Thermistors for Temperature Control
# 2 Selecting and Using Thermistors for Temperature Control Selecting and Using Thermistors for Temperature Control Thermally sensitive resistors (thermistors) are used widely in laser diode and detector
More informationLimiting factors in fiber optic transmissions
Limiting factors in fiber optic transmissions Sergiusz Patela, Dr Sc Room I/48, Th. 13:00-16:20, Fri. 9:20-10:50 sergiusz.patela@pwr.wroc.pl eportal.pwr.wroc.pl Copying and processing permitted for noncommercial
More informationQuantum Encoder and Decoder for Secret Key Distribution with Check Bits
Research Journal of Applied Sciences, Engineering and Technology 6(23): 4381-4386, 2013 ISSN: 2040-7459; e-issn: 2040-7467 Maxwell Scientific Organization, 2013 Submitted: January 31, 2013 Accepted: May
More informationOptical vector network analyzer for single-scan measurements of loss, group delay, and polarization mode dispersion
Optical vector network analyzer for single-scan measurements of loss, group delay, and polarization mode dispersion Dawn K. Gifford, Brian J. Soller, Matthew S. Wolfe, and Mark E. Froggatt We present a
More informationEmail: tjohn@mail.nplindia.ernet.in
USE OF VIRTUAL INSTRUMENTS IN RADIO AND ATMOSPHERIC EXPERIMENTS P.N. VIJAYAKUMAR, THOMAS JOHN AND S.C. GARG RADIO AND ATMOSPHERIC SCIENCE DIVISION, NATIONAL PHYSICAL LABORATORY, NEW DELHI 110012, INDIA
More informationIN RECENT YEARS, the increase of data transmission over
1356 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 8, AUGUST 2004 A 3.125-Gb/s Clock and Data Recovery Circuit for the 10-Gbase-LX4 Ethernet Rong-Jyi Yang, Student Member, IEEE, Shang-Ping Chen, and
More informationData Transmission. Data Communications Model. CSE 3461 / 5461: Computer Networking & Internet Technologies. Presentation B
CSE 3461 / 5461: Computer Networking & Internet Technologies Data Transmission Presentation B Kannan Srinivasan 08/30/2012 Data Communications Model Figure 1.2 Studying Assignment: 3.1-3.4, 4.1 Presentation
More informationPIPELINE LEAKAGE DETECTION USING FIBER-OPTIC DISTRIBUTED STRAIN AND TEMPERATURE SENSORS WHITE PAPER
PIPELINE LEAKAGE DETECTION USING FIBER-OPTIC DISTRIBUTED STRAIN AND TEMPERATURE SENSORS WHITE PAPER Lufan Zou and Taha Landolsi OZ Optics Limited, 219 Westbrook Road, Ottawa, ON, Canada, K0A 1L0 E-mail:
More informationAttaching the PA-A1-ATM Interface Cables
CHAPTER 4 Attaching the PA-A1-ATM Interface Cables To continue your PA-A1-ATM port adapter installation, you must attach the port adapter cables. The instructions that follow apply to all supported platforms.
More informationCHAPTER 11: Flip Flops
CHAPTER 11: Flip Flops In this chapter, you will be building the part of the circuit that controls the command sequencing. The required circuit must operate the counter and the memory chip. When the teach
More informationDesign and Test of Fast Laser Driver Circuits
Design and Test of Fast Laser Driver Circuits Since the invention of the laser by Theodore H Maiman 50 years ago, lasers have found widespread applications in various technological fields, such as telecommunications,
More informationChallenges in DWDM System Spectral Analysis By Laurent Begin and Jim Nerschook
Challenges in DWDM System Spectral Analysis By Laurent Begin and Jim Nerschook TABLE OF CONTENTS: 1.0 Satisfying the Thirst for Bandwidth 02 2.0 The Solution, DWDM 02 3.0 Resolution 04 4.0 Wavelength Accuracy
More informationSunny 1, Rinku Garg 2 Department of Electronics and Communication Engg. GJUS&T Hissar, India
Performance Analysis of Optical CDMA System Using W/T Codes Sunny 1, Rinku Garg 2 Department of Electronics and Communication Engg. GJUS&T Hissar, India Abstract This paper represents the performance of
More informationDIGITAL COUNTERS. Q B Q A = 00 initially. Q B Q A = 01 after the first clock pulse.
DIGITAL COUNTERS http://www.tutorialspoint.com/computer_logical_organization/digital_counters.htm Copyright tutorialspoint.com Counter is a sequential circuit. A digital circuit which is used for a counting
More informationEXPERIMENT NUMBER 5 BASIC OSCILLOSCOPE OPERATIONS
1 EXPERIMENT NUMBER 5 BASIC OSCILLOSCOPE OPERATIONS The oscilloscope is the most versatile and most important tool in this lab and is probably the best tool an electrical engineer uses. This outline guides
More informationFiber Optics: Fiber Basics
Photonics Technical Note # 21 Fiber Optics Fiber Optics: Fiber Basics Optical fibers are circular dielectric wave-guides that can transport optical energy and information. They have a central core surrounded
More informationAdding Heart to Your Technology
RMCM-01 Heart Rate Receiver Component Product code #: 39025074 KEY FEATURES High Filtering Unit Designed to work well on constant noise fields SMD component: To be installed as a standard component to
More informationMeasuring of optical output and attenuation
Measuring of optical output and attenuation THEORY Measuring of optical output is the fundamental part of measuring in optoelectronics. The importance of an optical power meter can be compared to an ammeter
More informationLaser-induced surface phonons and their excitation of nanostructures
CHINESE JOURNAL OF PHYSICS VOL. 49, NO. 1 FEBRUARY 2011 Laser-induced surface phonons and their excitation of nanostructures Markus Schmotz, 1, Dominik Gollmer, 1 Florian Habel, 1 Stephen Riedel, 1 and
More informationExperimental investigation of a coherent quantum measurement of the degree of polarization of a single-mode light beam
JOURNAL OF MODERN OPTICS, 2003, VOL. 50, NO. 11, 1679 1690 Experimental investigation of a coherent quantum measurement of the degree of polarization of a single-mode light beam M. LEGRE, M. WEGMULLER
More informationExperimental plug and play quantum coin flipping
Experimental plug and play quantum coin flipping Anna Pappa, Paul Jouguet, Thomas Lawson, André Chailloux, Matthieu Legré, Patrick Trinkler, Iordanis Kerenidis, Eleni Diamanti To cite this version: Anna
More informationWith the advent of Gigabit Ethernet
INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT Int. J. Network Mgmt 2001; 11:139 146 (DOI: 10.1002/nem.396) The importance of modal bandwidth in Gigabit Ethernet systems By David N. Koon Ł This article deals
More informationTi:Sapphire Lasers. Tyler Bowman. April 23, 2015
Ti:Sapphire Lasers Tyler Bowman April 23, 2015 Introduction Ti:Sapphire lasers are a solid state laser group based on using titanium-doped sapphire (Ti:Al 2O 3) plates as a gain medium. These lasers are
More informationThe Phase Modulator In NBFM Voice Communication Systems
The Phase Modulator In NBFM Voice Communication Systems Virgil Leenerts 8 March 5 The phase modulator has been a point of discussion as to why it is used and not a frequency modulator in what are called
More informationPump-probe experiments with ultra-short temporal resolution
Pump-probe experiments with ultra-short temporal resolution PhD candidate: Ferrante Carino Advisor:Tullio Scopigno Università di Roma ƒla Sapienza 22 February 2012 1 Pump-probe experiments: generalities
More informationSol: Optical range from λ 1 to λ 1 +Δλ contains bandwidth
1. Use Figure 3.47 and Figure 3.50 to explain why the bandwidth of twisted-wire pairs and coaxial cable decreases with distance. Figure 3.47 figure 3.50 sol: The bandwidth is the range of frequencies where
More information10 Gb/s WDM-PON Using Downstream OFDM and Upstream OOK
10 Gb/s WDM-PON Using Downstream OFDM and Upstream OOK Jing Huang, Deming Liu & Cheng Zeng College of Optoelectronic Science and Engineering Huazhong University of Science and Technology, Wuhan 430074,
More informationINTERFERENCE OF SOUND WAVES
1/2016 Sound 1/8 INTERFERENCE OF SOUND WAVES PURPOSE: To measure the wavelength, frequency, and propagation speed of ultrasonic sound waves and to observe interference phenomena with ultrasonic sound waves.
More information