Accession Number : AD0721372

Title :   The Behavior of Laser Modes in a Medium with Time Varying Dielectric Constant.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Whitney,Colin Gordon

Report Date : 25 AUG 1970

Pagination or Media Count : 170

Abstract : The effect, on semiconductor laser modes, of a time-varying modulation of the complex dielectric constant of the active region of the laser, is considered. It is seen that the main effect is to produce frequency modulation associated with modulation of the real part of the dielectric constant while modulation of the imaginary part gives rise to amplitude modulation. Two methods for producing the modulation are considered. The first, pressure via ultrasonic waves, produces pure frequency modulation in impure material. The second, modulation of the injection, results in both amplitude and frequency modulation. Experiments to confirm this analysis were carried out on a cw GaAs injection laser. The modulated laser spectrum was observed with a Fabry-Perot Interferometer. High resolution measurements on the pulsed spectral shift of a GaAs laser at 77K and 4.2K were performed using a Fabry-Perot interferometer. The feasibility of detecting modulation on a pulsed semiconductor laser was demonstrated. (Author)

Descriptors :   (*LASERS, FREQUENCY MODULATION), (*INFRARED LASERS, OPTICAL COMMUNICATIONS), ULTRASONIC RADIATION, FREQUENCY SHIFT CONVERTERS, GALLIUM ARSENIDES, PARTIAL DIFFERENTIAL EQUATIONS, DIELECTRIC PROPERTIES, GAIN, AMPLITUDE MODULATION, THESES

Subject Categories : Lasers and Masers
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE