Low threshold Ga xIn 1− xP/(Al yGa 1− y) 0.5In 0.5P strained quantum well lasers

Abstract

Strained Ga x In 1- x P/(Al y Ga 1- y ) 0.5In 0.5P quantum well (QW) lasers have been prepared by low pressure organometallic vapor phase epitaxy. By adjusting the QW active region composition and thickness, (300 K pulsed) wavelengths of 617 to 712 nm have been obtained. In the longer wavelength (λ > 670 nm) regime, where compressive strain ( x < 0.5) is applied, low threshold current density ( J th = 220 A/cm 2) and high characteristic temperature ( T 0 > 150 K) are demonstrated. For shorter wavelengths, where electron confinement begins to diminish, thresholds are higher and T 0 is lower, for both compressive- and tensile-strained ( x > 0.5) QWs. At 633 nm, best properties are J th = 400 A/cm 2 and T 0 = 60 K. The characteristic temperature can be improved by using multiple, rather than single, QWs.