Title :
Picosecond CO2laser-induced self-defocusing in InSb
Author :
Sheik-Bahae, Mansoor ; Kwok, Hoi-Sing
Author_Institution :
Center for research in electro-optics and lasers, University of Central Florida, Orlando, Fl., USA
fDate :
11/1/1987 12:00:00 AM
Abstract :
Self-defocusing of 45 ps CO2laser pulses was observed in InSb at intensities as low as 1 MW/cm2. This self-defocusing was caused by the two-photon absorption generated free carriers and the resulting self-phase modulation. In addition to demonstrating spatial beam modulation in this material at 10.6 μm, the present experiment also confirms directly that such a process occurs on a picosecond time scale. This information is important in order to increase the switching speed of infrared optical bistable devices to the picosecond regime. Furthermore, the present self-defocusing experiment also provided an accurate determination of the two-photon absorption coefficient in InSb. The value of 2.5 cm/MW obtained agrees exactly with a previous study. Other applications to continuum and ultrashort pulse generation will also be discussed.
Keywords :
Carbon dioxide lasers; Indium materials/devices; Laser-beam focusing; Optical propagation in nonlinear media; Optical propagation, semiconducting media; Optical transient propagation; Free electron lasers; Laser beams; Nonlinear optics; Optical bistability; Optical devices; Optical pulse generation; Optical pulses; Optical refraction; Optical variables control; Ultrafast optics;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.1987.1073249
