Future Trends in Microelectronics: From Nanophotonics to Sensors to Energy

GaSb-based Type-I Laser Diodes Operating at 3 μm and Beyond

L. Shterengas, G. Kipshidze, T. Hosoda, and G. Belenky

Department of Electrical and Computer Engineering, SUNY–Stony Brook Stony Brook, NY 11794-2350, U.S.A.

1.   Introduction

Laser light sources operating in the spectral region near 3 μm are required for variety of applications, ranging from aesthetic surgery to remote spectroscopic analysis. Semiconductor diode lasers operating at room temperature (RT) with watt-level continuous wave (cw) output power can benefit the design of the corresponding systems due to their inherent stability, compactness, and possibly low cost and high efficiency. Until recently, the very idea of cw diode lasers operating at RT with wavelength λ ~ 3 μm was thought to be questionable. This pessimism originated in the well-known fundamental increases of the nonradiative Auger recombination and of free carrier absorption with wavelength. The associated carrier and photon losses were considered likely to prevent the mid-infrared (mid-IR) diode lasers from reaching cw lasing at RT.

Today, cw RT operation of 3 μm diode lasers with hundreds of mW of output power is a reality. Clearly, this experimental fact casts doubt on the validity of the old argument based on the destructive power of Auger recombination and free carrier absorption. Moreover, the narrow bandgap nature of the active region not only brings disadvantages but also can provide significant benefits. The advantage of using narrow bandgap ...