ABSTRACT
The present status of nitride-based laser diodes (LDs) made by plasma-assisted molecular beam epitaxy (PAMBE) is reviewed. We demonstrate continuous-wave LDs operating in the range of 408–482 nm on (0001) c-plane bulk GaN substrates and ultraviolet LDs at 390 nm on ( 20 2 ¯ 1 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315151595/260c4d72-cfcf-45d4-8599-8f9a5ea0a739/content/eqni14_1.jpg"/> semipolar GaN substrates. The peculiarities of low-temperature GaN and InGaN growth by PAMBE are discussed. Recent improvements of InGaN growth have allowed us to demonstrate high-quality quantum wells (QWs) and excellent morphology for thick InGaN layers. The use of high N fluxes—up to 3 μm/h—during the InGaN growth was essential to push the lasing wavelengths of PAMBE LDs above 460 nm. The novel LDs design with the InGaN waveguides is demonstrated. We discuss 322the influence of thickness and composition of InGaN waveguides on the internal and external LDs parameters. Additionally, a solution to the problem of light leakage to GaN substrate is proposed.
