[OPTICAL REVIEW Vol. 21, No. 3 (2014) 206-209]
© 2014 The Japan Society of Applied Physics

InGaAs Circular-Grating-Coupled Surface Emitting Laser with Focusing Function Fabricated by Electron Beam Writing with Circular Scanning

Ashim Kumar SAHA, Masahiro UEMUKAI, and Toshiaki SUHARA

Department of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan

(Received December 13, 2013; Accepted February 16, 2014)

We report the design, fabrication and operation of an InGaAs QW circular-grating-coupled surface emitting laser (CGCSEL) which can focus the output laser beam. Circular distributed Bragg reflector and circular chirped grating coupler were fabricated by electron beam lithography employing smooth circular scanning and two step reactive ion etching. Single-mode-like lasing at a wavelength of 978.3 nm was accomplished. Focusing function was confirmed and the focused spot size around 80 μm was obtained.

Key words: surface emitting laser, distributed Bragg reflector, focusing grating coupler, integrated optoelectronics, electron beam lithography, circular gratings