Criteria to obtain independent modes in a homogeneous laser medium.

摘要

This dissertation presents the sufficient conditions required of a laser system to achieve simultaneous lasing of two or more closely spaced laser modes when other modes have already been established in the laser. Saturation of the gain medium and spatial holes burned into the gain medium are used in this analysis. The first mode to lase is considered to be higher on the gain curve than the second mode.; Next, the laser modes are considered that have a phase difference between them. The phase of a mode is taken with respect to the beginning of the gain medium. That is, the gain medium can be any length in the cavity and located at any position in the cavity. Sufficient conditions for lasing of multiple modes is derived based on this theory. An optimal gain medium length is derived based on this theory, as well as, an optimal gain medium position inside of the cavity. It is also determined that the best phase difference between two modes is 90°.; It was determined that as more modes are added to the cavity the requirements for these new modes to exist inside of the cavity become more stringent due to the depletion of the available electrons by the existing modes.