Lead salt microdisk lasers operating in continuous wave mode at 5.3 μm wavelength

Lead salt microdisk lasers with midinfrared emission around 5.3 μm are demonstrated. The laser structures were grown by molecular beam epitaxy on BaF2 substrates and consist of Pb0.95Sr0.05Se spacer layers and a ten-period PbSe/Pb0.95Sr0.05Se multi-quantum-well active region. Under optical excitation, single mode continuous-wave lasing is obtained up to temperatures of 135 K from microdisks with a diameter of 45 μm. With increasing temperature the laser emission continuously switches to resonator modes at shorter wavelengths. The lasers exhibit a threshold pump power of only 1.47 mW (75 W/cm2) at 115 K.