Title :
Theory of optical nutation in direct-gap semiconductors due to ultrashort resonant laser irradiation
Author :
Singh, Kanta ; Sen, Pintu ; Sen, Pranay K.
Author_Institution :
Dept. of Phys., Bhopal Univ., India
Abstract :
An analytical investigation of optical nutation in direct-gap semiconductors such as GaAs, InSb, and Hg/sub 1-x/Cd/sub x/Te based on the time-dependent perturbation technique is discussed. The crystals are considered to be irradiated by short pulsed moderate power near-resonant lasers producing significant density of optically-induced free electron-hole pairs. Incoherent dephasing mechanisms have been introduced phenomenologically into the coherent radiation-semiconductor interaction model. The theory, on application to the case of a specific crystal such as Hg/sub 1-x/Cd/sub x/Te with x=0.18 irradiated by a pulsed 10.6 mu m CO/sub 2/ laser, manifests distinctly the occurrence of ringing behavior in the transmitted intensity, transient dispersion, and absorption even in the absence of any theoretical averaging or the consideration of the effective density of states.<>
Keywords :
II-VI semiconductors; cadmium compounds; laser beam effects; mercury compounds; optical coherent transients; semiconductors; 10.6 micron; CO/sub 2/ laser; GaAs; Hg/sub 1-x/Cd/sub x/Te; II-VI semiconductors; III-V semiconductors; InSb; absorption; coherent radiation-semiconductor interaction model; direct-gap semiconductors; incoherent dephasing mechanisms; optical nutation; optically-induced free electron-hole pairs; ringing behavior; short pulsed moderate power near-resonant lasers; time-dependent perturbation technique; transient dispersion; transmitted intensity; ultrashort resonant laser irradiation; Crystals; Free electron lasers; Gallium arsenide; Laser modes; Laser theory; Mercury (metals); Optical pulses; Perturbation methods; Power lasers; Tellurium;
Journal_Title :
Quantum Electronics, IEEE Journal of