4.8 mu m vertical emitting PbTe quantum-well lasers based on high-finesse EuTe/Pb1-xEuxTe microcavities

Vertical laser emission at 4.8 mu m from PbTe quantum wells in high-finesse Pb0.95Eu0.05Te/EuTe microcavity structures at temperatures between 35 and 85 K is reported. The vertical-cavity laser structure was grown by molecula r-beam epitaxy on BaF2(111) substrates, and consisted of a 2 lambda cavity with four 20 nm quantum wells at the cavity antinodes. Laser emission was e xcited by optical pumping with a pulsed Nd:YVO4 laser. The comparison of th e cavity mode positions with envelope function calculations of the quantum- well energy levels indicates that, in this temperature range, lasing is due to transitions between the ground level of the oblique valleys in the cond uction and valence bands. (C) 2000 American Institute of Physics. [S0003-69 51(00)03614-7].