Abstract

(AlGaIn)P bulk and quantum well heterostructures, grown on GaAs substrates, are being intensively studied for visible laser diode and LED applications, because of the large room-temperature direct energy gaps (up to ~2.3eV) which they offer. Early effort has concentrated on the lattice-matched Ga_0.52In_0.48P–(Al_yGa_1–y)_0.52In_0.48P system. In this case¹, laser action has typically been achieved at -660 to 680nm at room temperature, with threshold current densities of at best 0.2 – 0.4 kA cm⁻². These lasers have commonly shown rapid degradation in threshold current density as the temperature is increased above 294K. Recently, in an effort to improve performance and shorten the operating wavelength, laser structures with (GaIn)P quantum well active regions under coherent strain on the GaAs substrate have been produced. Both¹ compressively and tensile strained active layer lasers have been investigated, with strain of up to ~1% in each case.

© 1993 Optical Society of America