Theoretical study of optimum operation of two-longitudinal-mode optically pumped miniature FIR laser

摘要

The optimum operation of two-longitudinal-mode optically pumped miniature far infrared (FIR) laser was theoretically studied via semi-classical density matrix equation. The effect of laser structural and operating parameters on the output power was calculated. The quantum transitions related to 90.4 µm FIR laser emission in the ammonia (NH_3) molecular system pumped by two-mode CO_2-9R(16) laser line was quantified in three-energy-level model that revealed a proportional relationship of the reduced pumping power with the thickness of the absorbed NH_3. The effective activated length became longer and adjusted to be equaled to the length of the fixed laser cavity.