LASERS and Related Apparatus

LASER Experiences

1) ns Excimer laser & Dye laser (at Tokyo Metropolitan University)
Lumonics Hyper EX-400: 308 nm (XeCl)
Lumonics Hyper EX-300

2) ps Diode Laser (at Tokyo Metropolitan University)
with Streak Camera

3) ps Nd:YAG Laser and OPA (at Tokyo Metropolitan University)
Exspla PL2143B: 30ps, 1064 nm (80mJ), 532 nm(40 mJ), 355 nm (33 mJ), 266 nm(15 mJ),
Exspla PG401V: 420-650 nm (> 1 mJ)

4) ns Excimer laser (at OCU)
Lambda Physik LPF205:

5) ns Excimer laser (at OCU)
Lambda Physik COMPex102:

6) fs Ti:Sapphire laser & OPA (at Max-Planck-Institute for Quantum Optics)
Spectra Physics Super Spitfire: 50 fs, 800 nm (> 2 mJ), 1 kHz
LightConversion TOPAS

7) fs Ti:Sapphire laser & OPA (at OCU)
Thales Lasers Alpha 100/XS: < 30fs, 800nm (> 15 mJ), 100 Hz
(Osillator: Femto lasers Femtosource s20, 20 fs, 76 MHz, 500 mW, 800 nm)
(Pump: Thales laser JEDI, 7ns, 100 Hz, 120 mJ, 532 nm)

Oscillator is always a seed of trouble.

The output pulse train from the oscillator (Femto lasers, Femtosource s20, 20 fs, 76 MHz, 500 mW, 800 nm) pumped by a Nd:YVO4 laser (Coherent, VERDI V5, 5 W, 532 nm) was temporally stretched by an 8 pass Offner-type stretcher. After stretching, the pulse was selected and modulated by the AOPDF (acoustooptic programmable dispersive filters, Fastlite, Dazzler). The modified pulse was amplified in a regenerative amplifier (Ti:sapphire). The extracted single pulse was then fed into a pulse cleaner (Pockels cell and polarizer pair) to attenuate pre-pulses on nanosecond timescale produced by the regenerative amplification process and then amplified in 4 pass amplifier (Ti:sapphire). A regenerative amplifier and 4 pass amplifier were both pumped by a diode laser pumped Nd:YAG laser (Thales laser, JEDI, 7ns, 100 Hz, 120 mJ, 532 nm). Amplified pulse was compressed by a pair of grating. The picosecond contrast ratio was measured by the third-order cross-correlator. The contrast ratio was > 2~104 : 1 (1ps), > 105 : 1 (5 ps), > 106 : 1 (10 ps), respectively. The nanosecond pre-pulse contrast ratio was >5~105 : 1 (8 ns) measured by a fast pin-photodiode. RMS stability of the output energy was around 1 %. The beam quality factor (M2) was less than 1.4 on both axis. The energy of the laser pulses was attenuated by a combination of a motorized half-waveplate and a polarizer placed before the multipass amplifier. The duration of laser pulse can vary from 30 fs to 1 ps by adjusting the distance between gratings and also by the AOPDF. AOPDF can compensate both 2nd and 3rd order dispersion. The pulse width was measured by a second order single-shot autocorrelator (Thales Laser, TAIGA).

LightConversion: TOPAS 100 fs
LightConversion: TOPAS 30 fs

8) sub-ns N2 laser (at OCU)
UshoKEN-810 (337.1 nm, 80 μJ, 600 ps, 10 Hz) for educational use


* home made single shot autocorrelator (> 6 fs)
* home made whight light generation and pulse compression system (with Dr. Subhasis Panja)