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

Lead salt microdisk lasers with midinfrared emission around 5.3 mu m are demonstrated. The laser structures were grown by molecular beam epitaxy on BaF(2) substrates and consist of Pb(0.95)Sr(0.05)Se spacer layers and a ten-period PbSe/Pb(0.95)Sr(0.05)Se 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 mu m. 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/cm(2)) at 115 K.