Stable in-Phase Mode Operation in Coherent VCSEL Array With an Integrated Phase Shifter

• Published in: IEEE transactions on electron devices Vol. 67; no. 7; pp. 2819 - 2824
• Main Authors: Xun, Meng, Sun, Yun, Jiang, Xiaowei, Zhang, Runze, Zhou, Jingtao
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Coatings; Far fields; In-phase mode; Laser arrays; Laser beams; Measurement by laser beam; Phase shifters; Phased arrays; proton implantation; Sidelobes; Single mode operation; Vertical cavity surface emission lasers; Vertical cavity surface emitting lasers; vertical-cavity surface-emitting laser (VCSEL) coherent array
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2020.2994274

Implant-defined coherent vertical-cavity surface-emitting laser (VCSEL) arrays with an integrated phase shifter that can convert the out-of-phase mode into the in-phase mode were demonstrated. The measured angular full-width at half-maximum (FWHM) from a <inline-formula> <tex-math notation="LaTeX">{9} \times {9} </tex-math></inline-formula> coherent VCSEL array in the far-field lobes is only 0.82°. The intensity of the central lobe is about 2.9 times than that of surrounding sidelobes, showing excellent beam quality. The FWHM of the spectrum of a <inline-formula> <tex-math notation="LaTeX">{9} \times {9} </tex-math></inline-formula> array is only 0.02 nm, showing a single-mode operation. It provides a potential method to fabricate larger in-phase coherent VCSEL arrays. A remaining challenge is enhancing output power via solving the heat problem.