The parametric transformation of acoustic and optical phonons in doped superlattices is theoretically studied by using a set of quantum kinetic equations for the phonons. The analytic expression of parametric transformation coefficient of acoustic and optical phonons in doped superlattices is obtained, that depends non-linear on the concentration of impurities. Numerical computations of theoretical results and graph are performed for GaAs:Si/GaAs:Be doped superlattices
Excimer lasers are pulsed gas lasers that intrinsically offer efficient and powerful
broadband emission at several spectral regions throughout the ultraviolet.
The spectral widths are typically 2 nm. An exception to this categorization is the
XeF laser urith its broadly tunable C+A transition (approximately 50 nm) in the
visible. The broad tunability results from the steeply repulsive A state.
Although we are well into the fourth decade since the advent of the laser, the number
and type of lasers and their wavelength coverage continue to expand. One seeking a
photon source is now confronted with an enormous number of possible lasers and laser
wavelengths. In addition, various techniques of frequency conversion—harmonic
generation, optical parametric oscillation, sum- and difference-frequency mixing, and
Raman shifting—can be used to enlarge the spectral coverage.