Optically pumped intersubband lasers based on quantum wells

Analysis of a quantum well-based far infrared laser that employs optical pumping to incorporate population inversion in the laser reveals that a high pumping power density is essential to induce population inversion in the valence band structure with high intersubband scattering rates while a moderate pumping power density is sufficient in the conduction band structure. A maximum population inversion of 2.1 times 10 to the power of 11 sq cm is seen for conduction band structure at 2 kW/sq cm of pumping power density.