Picosecond CO/sub 2/ laser-induced self-defocusing in InSb

Journal Article · Sun Nov 01 04:00:00 EST 1987 · IEEE J. Quant. Electron.; (United States)

DOI:https://doi.org/10.1109/JQE.1987.1073249· OSTI ID:5742952

Sheik-Bahae, M; Kwok, H S

Self-defocusing of 45 ps CO/sub 2/ laser pulses was observed in InSb at intensities as low as 1 MW/cm/sup 2/. 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 ..mu..m, 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 are also discussed.

• Research Organization: Dept. of Electrical and Computer Engineering, State Univ. of New York at Buffalo, Amherst, NY 14260
• OSTI ID: 5742952
• Journal Information: IEEE J. Quant. Electron.; (United States), Journal Name: IEEE J. Quant. Electron.; (United States) Vol. QE-23:11; ISSN IEJQA
• Country of Publication: United States
• Language: English

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36 MATERIALS SCIENCE
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42 ENGINEERING
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ABSORPTION
ALLOYS
CARBON DIOXIDE LASERS
CHARGE CARRIERS
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
FOCUSING
FUNCTION GENERATORS
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INDIUM ALLOYS
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LASER MATERIALS
LASERS
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MODULATION
OPERATION
OPTICAL PROPERTIES
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PULSE GENERATORS
PULSE RISE TIME
PULSES
RADIATIONS
TIMING PROPERTIES
TIN ALLOYS