TEMPERATURE-DEPENDENT EFFICIENCY AND MODULATION CHARACTERISTICS OF AL-FREE 980-NM LASER-DIODES

Temperature dependent efficiency and modulation characteristics of str ained quantum-well (QW) InGaAs-InGaAsP-InGaP 980-nm laser diodes of va rious designs are analyzed using self consistent carrier transport ana lysis including stimulated emission. The decrease of the differential efficiency of 980-nm laser diodes with temperature is found to be caus ed by an increased modal loss attributed to the free carrier (electron and hole) absorption. The obtained results agree well with experiment ally observed increase of internal loss at higher temperatures. Modula tion characteristics are determined mainly by drift-diffusion in separ ate confinement region along with processes of carrier capture and esc ape in QW's. At high temperatures modulation bandwidth is reduced beca use of the decrease in differential gain. Graded index separate confin ement heterostructure and multi-QW lasers show superior efficiency and modulation behavior at high temperatures.