Laser Based Micro and Nanoscale Manufacturing and Materials Processing Faculty: Prof. Xianfan Xu Email: xxu@ecn.purdue.edu Phone: (765) 494-5639 http://widget.ecn.purdue.edu/~xxu Research Areas: Development of laser based micro and nano manufacturing technologies Micro and Nanoscale heat/energy transfer in laser manufacturing processes, particularly, high power, ultrafast laser (pulse width ~ 100 fs) materials interactions Laser manufacturing of MEMS/NEMS, microsensors and microelectronics Sponsors : NSF, ONR, State of Indiana, DoD, IBM, Intel, Knolls Atomics, Sandia National Lab, Affiliated with Center for Laser Micro-fabrication, Center for Advanced Manufacturing, and Birck Nanotechnology Center
Fundamentals of Femtosecond Laser Interaction with Materials Experimental and numerical studies are being conducted to investigate energy coupling and transfer during femtosecond laser matter interaction. Imaging of laser induced plasma in glass Bi film 365 fs (2.74THz) Reflectivity Molecular dynamics simulation of femtosecond laser ablation (laser irradiates from right) -2-1 0 1 2 3 4 5 Time delay (ps) Phonon oscillation observed during laser-matter interaction
Femtosecond Laser Micro Machining A femtosecond laser system is being used to fabricate various micro structures and components. Because of the very short laser pulse duration, heat dissipation is confined, resulting in cleaner machining results. The various non-linear and non-equilibrium processes during laser matter interaction are also utilized to machine microstructures in transparent materials (figure on right). Laser fabricated 4-bar linkage 0.5 mm 0.5mm Purdue logo fabricated inside glass Microoptics: Fresnel zone plate Laser writing of optical waveguides and 3D optical components.
Laser Direct-Write of Microsystems LDW Laser Direct Write and LS Laser Sintering systems allow the fabrication of microelectronics with integrated chemical/biological components from a CAD file. Thermal modeling improves performance of directwrite system. Capable of fabricating microelectronic and energy conversion devices, and on low-temperature, flexible substrates that cannot otherwise be fabricated. Silver Dielectric Parallel-plate capacitor on glass substrate CCD Camera XY Scanner Fiber Laser Nd:YLF Laser Patch antenna on flexible Mylar substrate Path of laser Laser Hot Mirror Flip Mirror Stages Laser Direct-Write Apparatus z Ink-substrate interface x Thermal model of laser writing process
Nanoscale Optical Antenna and Its Application in Nano manufacturing Objective: to realize nanoscale confinement of light, for applications such as ultrahigh density data storage, nanoimaging, and nanomanufacturing. Theory: Nanoscale optical near-field confinement combining confined waveguide propagation and resonant optical transmission and excitation of localized surface plasmon. Design: finite-deference time-domain (FDTD) numerical computations for optimization. Characterization: home-developed near-field scanning optical microscopy (NSOM). Bowtie nano antenna array fabricated by focused ion beam milling Spectrum response (A.U.) 4 3.5 3 2.5 2 E field (A.U.) 1.5 1 0.5 0-0.5-1 -1.5 0 5 10 15 20 25 t (ps) 1.5 1 0.5 300 400 500 600 700 800 Wavelength (nm) Intensity 467 525 583 λ (nm) FDTD 50 Ag calculation for design and optimization nm Optical near field measurement
Optical Nanomanufacturing and Nanolithography develop nanomanufacturing technologies and understand the underling manufacturing, control, nano-optics, and energy transfer issues Nanomanufacturing facility, including high precision motion stages and optics housed in a clean environment Nanometer sized holes produced by high efficiency nanoscale optical antenna developed in this laboratory