PROBLEMS OF REALIZING A LONG-PULSE LENGTH, HIGH DUTY CYCLE P-GE LANDAU-LEVEL FIR LASER

The hot-hole p-Ge laser, which requires a large power density ((J) ove r bar.(E) over bar similar or equal to 10(5) watts/cm(3)) for excitati on, has fundamental heat dissipation and lattice temperature constrain ts that limit the laser pulse length and duty cycle that can be achiev ed. This paper presents a two-dimensional heat equation analysis of th e p-Ge laser bar configuration along with consideration of constraints of resonator size, heat sink dissipation limits, and temperature cut- off limits (similar to 20 degrees K). In order to realize a CW p-Ge la ser, the present bar sizes (typically 3 x 4 x 50 mm), would need to be decreased by over an order of magnitude and the heat sink dissipation capability appreciably increased. The detailed graphs and equations p resented provide design data for future p-Ge lasers and optimization d ata with respect to laser pulse length and duty cycle for existing las ers.