National Science Foundation Center for Lasers and Plasmas for Advanced Manufacturing Mool C. Gupta Applied Research Center Old Dominion University
National Science Foundation Center - Center Mission - Develop Science, Engineering and Technology Base for Laser and Plasma Processing of Materials, Devices and Systems for Advanced Manufacturing
Partnership Industry Fed. Labs Projects Univ. Overhead & Membership Facility Membership Funds & National CIT Membership State NSF Recognition
Industrial Advisory Board Members Science & Technology Corp. Spectra Physics NASA Langley Research Center Philip Morris Framatome ANP Jefferson Lab Economic Development Authority of the City of Newport News Virginia s Center for Innovative Technology Luna Innovations Materials Modification Inc. Vistakon
PROJECTS Projects Primary Interest Effect of Fs pulse width on micromachining (Spectra Physics) Laser induced compressive stresses (Framatome) Plasma Processing (CIT, EDA) Nanocatalysts for CO oxidation (Philip Morris) Nanostructures and Electron emission (Jefferson Lab) Carbon Nanotubes for EM Shielding (NASA-Langley, STC) Fullerenes (Luna Innovations) Nanoparticles (MMI) Optical Surfaces (Vistakon)
ADDITIONAL RESEARCH Laser Crystallization of a-si for Solar Cells (NSF & BPSolar) Laser Crystallization of Diamond like Carbon Films (Anatech,CIT) Butterfly Color Formation (Alcoa Corporation) Laser Texturing for Adhesion of Shape Memory Alloys (NASA) 121.6 nm VUV Lamp Source for Lithography (DARPA) BST Nanoparticles by Ablation for Microwave devices (to Army) Lasers for Art Cleaning & Preservation (to Dept. of Interior) Laser Hardening of Sensors (submitted to AFOSR) Fs laser holography,tera Hertz Applications and Electro-Optic Beam Scanner
Nanostructures & Electron Emission Primary Interest: Jefferson Lab. FEL High Charge > 1 nc; Polarization not important Pulse Duration~ 0.1-1 ps; I~ 100 ma Energy~ fraction of MeV; Emittance ~ 1 mm mrad Nuclear Physics Low Charge ~ 1 nc; Polarization~ 80% Pulse duration < 1 ps; I~ 100 µa Energy~fraction of MeV; Emittance not important
Nanostructures & Electron Emission Carbon Nanotubes Current Density:10-100 A/cm 2 Emission Pulse width: Picosecond Repetition Rate: 10-100 MHz Emission Area: > 1 cm 2 Dong, Xu and Gupta
Carbon Nanotube Electron Emission Imaging from CNT ITO Film Phosphor CNT Dong, Myneni and Gupta
RESULTS LINE STRUCTURE Still picture of single-pass cutting on Silicon τ p = 110fs τ p = 500fs τ p = 1ps Chien & Gupta τ p = 5ps τ p = 10ps
RESULTS LINE STRUCTURE * Laser cutting on Silicon @ E = 10 µj 3 2.5 2 1-pass 5-pass 10-pass 60 50 40 1.5 30 1 0.5 0 0 2 4 6 8 10 12 Pulse width (ps) 20 10 1-pass 5-pass 10-pass 0 0 2 4 6 8 10 12 Pulse width (ps) Chien & Gupta
LASER PEENING SET UP Bugayev and Gupta
X-RAY DIFFRACTION PATTERN of 316L 16 DIFFRACTED BEAM (a.u.) 14 12 10 8 6 4 2 [111] [200] STEEL 316L before LSP after LSP [220] 0 70 80 90 100 110 120 130 2Θ (degree) Bugayev and Gupta
Fs Laser Holography Bugayev and Gupta
Fs Laser Holography 0.48 mm Bugayev and Gupta
Balance photodiode Input laser Probe beam Xu and Gupta
7 Power Absorption Spectrum 6 Room temperature water vapor 5 4 3 2 1 0 1.0 1.5 2.0 2.5 Frequency (THz) Xu and Gupta
Aim: To improve the efficiency of Si solar cells. Diode Laser Laser Crystallization of a-si:h Set up Method: Crystallize a-si:h using a semiconductor laser. Diode Array Laser Beam Path Focusing Lens a-si:h film Sponsor: National Science Foundation Result CPS [a.u] Advantages: - Manufacturing Compatibility -Solar cell Stability. [111] 2θ XRD of crystallized Si Nayak & Gupta
Butterfly Color Formation Wong and Gupta
Butterfly Surface under SEM Wong and Gupta
Grating Fabrication Wong and Gupta
121.6 nm VUV Lamp Chamber for MIT-Lincoln Lab RF Input VUV Radiation for Materials Processing Si Detector Discharge Chamber Gas Input Spectra 20 15 Pressure = 500 Torr Flowrate = 900 Sccm 0.058% H2 RF = 60 W 10 5 Yan and Gupta 0 100 120 140 160 180 200 Wavelength (nm) Supported by DARPA
Some Experiments on Plasma Interaction with Materials RF input power 150W, Ar silicon plate 0.5mm T = 1683 K Akhmerov and Gupta
Yang and Gupta Plasma Modification of Surfaces Rotary stage Polymer film Plasma jet Roller
Plasma Processing Oxygen Treated Untreated PET Fluorochemical Yang, Mohajer and Gupta Teflon