High power lasers on InP substrates

Abstract

High power semiconductor lasers have found numerous applications in a wide variety of fields that include telecommunications, solid-state laser pumping, fiber laser pumping, direct laser, laser printing, and more recently in medical and cosmetic applications such as hair removal and skin treatment. So far, high power semiconductor lasers have been mainly designed with the AlGaAs/GaAs system since most of the demand was for YAG and Ytterbium laser pumping, which requires emission in the 800–1000nm range, and because AlGaAs/GaAs material is a much more efficient system in converting electrons into light than InGaAsP/InP or AlInGaAs/InP systems that are used in the 1300–1500nm range. High power long wavelength near-infrared lasers have always been a subject of interest for Raman amplification as well as for their “eye safe” properties compared to short wavelength near-infrared lasers. New emerging applications like wrinkle and acne removal, and body-fat removal also require longer wavelengths that are outside the spectrum of AlGaAs/GaAs system. Cosmetic uses of lasers for wrinkle or acne removal have already received FDA approval for “at home” use. This development may drive the demand for long wavelength near-infrared high-power lasers to millions of units/year as long as the cost constraint of consumer markets can be met. Thus there should be a growing demand in the future for low cost high power long wavelength semiconductor lasers that can emit CW power in the range of a few watts. This paper will cover how well InGaAsP/InP and AlInGaAs/InP lasers can satisfy this demand in terms of performance.