Nanosecond-Pulsed THz Laser and Phonon Spectroscopy Laboratory

College of Science Building Room 154

Laboratory Description

Wilson has in place most of the necessary components to conduct a suite of experiments in condensed-matter physics including a proposed study of the attenuation studies of near-THz transverse acoustic phonons in vitreous silica.. The laboratory is housed in room 154 of the College of Science Building. The large (9.8 m x 6.5 m x 2.25 m) air-conditioned laboratory is located on the ground floor and contains a fume hood, a sink, built-in oak cabinetry and shelves, and is wired for both 220 V and 120 V ac. (It should be mentioned also that a cleanroom shell is housed in a new Engineering Building across the street and NSF MRI proposals will be submitted to acquire photolithography/sputtering instrumentation for installation and use there.)

Equipment

  • Modified Gentec DD-250 TEA CO2 laser (grating-tunable ~1J/pulse at 10 pps)
  • Custom low-pressure CO2 gain cell (on occasion inserted inside the CO2 laser resonator for SLM performance)
  • Spectra-Physics GCR-150-10 YAG laser with Type II harmonic generator and dichroic separator: (produces 640-mJ @1064-nm and 360 mJ @ 532-nm in 8-10 ns pulses @ 10 pps) used for optical-switching of silicon
  • Custom cavity-dumped FIR laser resonator with cryo-absorption pumps for gas recycling and corrugated waveguide output beam transport,
  • Items 1-3 mounted on two Newport RS1000-5-12 optical tables with vibration isolation
  • Janis Research Co., Model 8 CNDT-5L optical immersion tail cryostat: temp range 1.4-4.2 K with 8-12 hour hold time, stainless connection lines, digital level indicator, and transfer tube. Temperature control is maintained by pumping on the vapor above the liquid helium bath through an MKS-653B throttle valve with an Oerlikon Sogevac SV-100B vacuum pump. The throttle valve aperture is adjusted under LabView control with an MKS-600 pressure controller with feedback from an MKS 626 pressure sensor.
  • JDS Uniphase NanoGreen pulsed diode laser (300-W, 1-ns pulses @ 17.5-kHz pps) used for broadband phonon generation and bolometer characterization studies
  • LeCroy WavePro 950 1-GHz digital oscilloscope
  • Leybold TOSS 50+ vacuum turbopump station
  • Stanford Research Corporation SRS 280/250/245/255/235/250 hi-speed dual gated integrator system
  • Avtech AVL-AV1-PS-T-P adjustable power and width, nanosecond pulse generator
  • Tektronics 2465A 350 MHz analog oscilloscope
  • Danielson Associates Tribodyn 150 oil-free molecular drag pump for pumping item 4
  • Varian 936-40 helium leak detector (rebuilt) for leak-checking the mm-wave laser resonator 15. HP 34420A nanovoltmeter
  • Keithley 224 programmable current source 13-14 used for bolometer characterization
  • Optical Engineering Co.model 16-A CO2 laser spectrum analyzer
  • Ortec 1-GHz preamplifier, Avtech Electropulse preamplifier.
  • Molectron Inc., J25, P3-00, and P5-00 pyroelectric detectors
  • Boston Electronics PEM-L-2 800MHz HgCdTe CO2 laser detector
  • SouthBay Technology model 150 Lapping/Polishing Station
  • Numerous Newport HeNe 2 mW lasers
  • 3 free-standing wire grid polarizers G30-10S Microtech Instruments, miscellaneous lens and laser mirrors
  • Complete precision 3-axis motion controller including Newport ESP300 controller with CMA25-CCCL piezo actuators and 462 3-axis translation stage (2 micron repeatability) for Fabry-Perot control and also for precise THz laser beam focusing onto the sample
  • Two pair of UVEX laser goggles for 532 nm, 1064 nm and 10.6 micron
  • Newport Jun-Air air compressor
  • Two MacBook Air notebook computers with Thunderbolt Displays and backup drives
  • Cryogenic uniaxial stress apparatus
  • Optical system for viewing quartz stress-field using crossed polarizers
  • Home-built FIR metal-mesh scanning Fabry-Perot interferometer
  • Home-built optical test jig for finishing crystals with flat parallel faces
  • Two Stanford Research Corp. DG-535 digital delay generators for triggering mm-wave laser
  • MKS Baratron pressure transducers (3 ea 10. Torr, 1 ea 1.0 Torr) and digital displays
  • Neslab water chiller (for CO2 laser)