High-performance 1.55-uM gallium indium nitride arsenide antimonide lasers grown on gallium arsenide.

摘要

Next-generation local and metro-area optical networks require high-performance lasers, detectors, and modulators operating at 1.55 mum. In contrast to long-haul networks, components must be very inexpensive, power efficient, and producible in high volumes---all with little sacrifice to performance. Two classes of lasers are required. The first is low-power (∼1-10 mW) 1.55-mum communication sources, such as vertical-cavity surface-emitting lasers (VCSELs), that must be insensitive to ambient temperature and operable at high modulation rates. The second class is higher output power (∼300 mW) lasers emitting at shorter wavelengths (∼1.48 mum) for pumping Raman and doped fiber amplifiers.; This work describes the development of a novel GaAs-based gain material, GaInNAsSb, which is ideal for both classes of lasers. Materials growth via molecular beam epitaxy is challenging, but optical quality can be improved dramatically through the introduction of antimony and other enhancements that are discussed. We demonstrate the first low-threshold GaAs-based lasers from 1.45-1.55 mum and the first GaAs-based QW laser >1.6 mum. Laser threshold current densities are as low as 440 A/cm2---comparable, if not superior, to commercially available InP-based devices. High continuous-wave output powers ∼400 mW, more than sufficient for amplifier applications, are achieved from even simple single quantum well structures. Laser results at 1.55 mum validate this new materials system for use in VCSEL sources as well. The temperature stability of these devices, the relevant physics, and methods for improvement are also discussed.