光栅耦合外谐振腔调谐的半导体量子级连激光器

本文研究了由InGaAs/InAlAs材料组成,波长为4.6和5.1微米的量子级连中红外半导体激光器的光栅外耦合谐振腔的特性。在温度是80K时波长可调制宽度是激光中心波长的1.5%左右。对于这两个激光器而言,它们的波长可调制宽度随温度升高而减低。被调制的单模激光器的输出光功率是几个毫瓦,激光的谱线宽度是1到2个微米。激光阈值电流随波长缓慢变化,然而激光输出效率在短波长时更加优化。

Grating-Tuned External- Cavity Quantum Cascade Semiconductor Lasers

Midinfrared InGaAs/InAlAs based semiconductor lasers with wavelength from 4.6 and 5.1 μm have been used in a grating tuned external cavity configuration. At 80K, a tuning range, up to ～1.5% of the center wavelength has been obtained. Both the Littman Metcalf and first order grating direct feedback cavity configurations were used with similar tuning results. The tuning ranges for both narrowed substantially with increasing temperature. Power of few mW peak has been demonstrated for single mode operation with ～1 2 nm linewidth. The threshold varied slowly vs. wavelength, while the efficiency appeared to be more optimum toward wavelengths shorter than the free running wavelength.