Sandwiched dual seed sources master oscillator power amplifier quantum cascade lasers.

To facilitate the development of compact multi-wavelengths lasers, we reported the experimental demonstration of dual seed sources master oscillator power amplifier (MOPA) QCLs. The devices were based on a sandwich configuration consisting of dual seed sources and a central power amplifier. Emission spectrum of devices was modulated by switching seed sources. By utilizing this design, two room temperature continuous-wave output power of 46 mW and 30 mW were obtained at modes 7.35 µm and 7.38 µm, respectively. The problem of power difference at the dual wavelengths have been improved. The two target modes were fine-tuning through current with tuning coefficients -0.0131 cmmA and -0.0122 cmmA, respectively. The reported compact quantum cascade lasers with dual seed sources and fine-tuning characteristics are significant for developing miniaturized and on-chip sensing systems with multi-gas accurate detection.