title: On-chip coherent combining of angled-grating diode lasers toward bar-scale single-mode lasers.
abstract: Single mode operation of broad-area diode lasers, which is the key to obtain high power, high brightness sources, is difficult due to highly nonlinear materials and strong coupling between gain and index. Conventional broad-area lasers usually operate with multiple modes and have poor beam quality. Laser bars usually consist of incoherently combined broad-area single emitters placed side by side. In this article, we have demonstrated a novel integrated laser architecture in which Bragg diffraction is used to realize simultaneous modal control and coherent combining of broad-area diode lasers. Our experimental results show that two 100 μm wide, 1.3mm long InP broad-area lasers provide near-diffraction-limited output beam and are coherently combined at the same time without any external optical components. Furthermore, our design can be expanded to a coherently combined broad-area laser array that turns a laser bar into a coherent single mode laser with diffraction-limited beam quality.
authors.affiliation: Department of Electrical and Computer Engineering, Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634, USA.
authors.forename: Yunsong
authors.initials: Y
authors.lastname: Zhao
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D054023:Lasers, Semiconductor; D012031:Refractometry / Q000295:instrumentation*; D018511:Systems Integration