Midinfrared lead-chalcogenide vertical external cavity surface emitting laser with 5μm wavelength

Midinfrared vertical external cavity surface emitting lasers for 5μm wavelength have been realized. The active parts consist either of a 2μm thick PbTe gain layer or of two 150nm PbTe layers embedded in Pb1−xEuxTe barriers, and an epitaxial two pair Pb1−yEuyTe∕BaF2 Bragg mirror. They are optically pumped with a 1.5μm laser. No precautions for efficient heat removal were implemented. The two-layer structure emits 1–2mW continuous wave at 95K with threshold pump power as low as ∼300mW. In pulsed mode, peak powers are >50mW, and lasing occurs up to ∼140K.