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The Optical Experiment

 

1.  Picosecond Laser Spectroscopy Equipment Facility:  This state-of-the-art facility is used to measure picosecond time-resolved photoluminescence and optical properties of semiconductors from infrared (IR) to ultraviolet (UV) spectral region. The system consists of 

• a picosecond (8 ps pulse width) dye laser driven by a Nd:YAG laser with a frequency doubler;

• a frequency doubler for the dye laser to provide a tunability in the UV region (285 -  310 nm) with an average power of 50 mW; a frequency tripler for the YAG laser to  provide a 100 ps laser source at 355 nm with an average power of 1 W;

• a closed-cycle He refrigerator with temperature range between 10 - 300 K;

• a 1.3-m monochromator with gratings operating in the region from 185 nm -  800 nm;

• a 0.5 m monochromator with a grating operating in the region of 800 nm - 170 nm;

• a streak camera detection system (2 picosecond time resolution) operating in the region of 185 - 800 nm;

• a microchannel plate photo-multiplier tube and a single photon counting detection system (25 ps time-resolution) operating in the region of 185 - 800 nm;

• a microchannel plate photo-multiplier tube and a single photon counting detection system (25 ps time-resolution) operating in the region of 800 nm - 1300 nm;

• an auto-correlator and a sampling scope (< 100 ps rise time) for monitoring YAG and dye laser pulse shape and UV optics and ultra fast pin photo-diodes. 

2. Femtosecond Laser System: A complete frequency Quadrupled Ti-Sapphire femtosecond laser system.  This laser system is specifically designed to generate femtosecond tunable deep UV (195-200 nm) laser light source with 10 mW average power.  This laser system together with our current detection system is the world¡¯s first deep UV (¦Ë > 195 nm) picosecond time-resolved optical measurement facilities dedicated to III-nitride semiconductor research and allows us to measure optical processes in AlGaN with AlN fraction all the way up to 100%. 

Below: An overhead diagram of the Optical Experiment setup:

Below: Dr. Robin Mair and Ke-Cai Zeng check out the setup:

mair&zeng_lg.jpg (57834 bytes)

Below:  The laser setup during operation:

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