Diode lasers of lead-europium-selenide-telluride grown by molecular beam epitaxy

Abstract

It is desirable to extend the wavelength coverage of PbSnTe diode lasers to shorter wavelengths (λ<5 μm) and higher operating temperatures. Currently, this range is covered by PbSxSe1−x diode lasers operating below 100 K. Double heterojunction diode lasers have now been fabricated using a new materials system, Pb1−xEuxSeyTe1−y. These structures were grown lattice matched to (100) oriented PbTe substrates by molecular beam epitaxy using PbTe, Eu, Te, PbSe, Tl2Te (p dopant), and Bi2Te3 (n dopant) source ovens. Mesa diodes were fabricated with 20-μm-wide stripes using anodic oxide insulation. Diodes have so far been fabricated with up to x=0.010, y=0.011, which operated cw from 4.93 μm (at 30 K) to 4.06 μm (at 136 K). Diodes with x=0.0015, y=0.0020 have operated up to 147 K cw. This is the highest cw operating temperature ever attained with lead-chalcogenide diode lasers. A wide range of single mode operation with ∼1 mW output power was observed for some of the better diodes. These diodes are useful for ultrahigh resolution spectroscopy, and may be useful in the future for low-loss, long-wavelength fiber optics communications.