Circular-grating surface-emitting distributed Bragg reflector lasers on an InGaAs-GaAs structure for 0.48-μm applications

In this paper, we report on the design and fabrication of electrically-pumped circular-grating surface-emitting DBR lasers for operation in the 0.98-/spl mu/m wavelength range. The layer structure with InGaAs-GaAs-AlGaAs strained multiquantum-wells was obtained by one-step epitaxial growth. Circular gratings are defined by electron-beam lithography around circular gain sections of different diameters. Low threshold CW operation as low as 26 mA for a 60-/spl mu/m diameter gain section, and high-power pulsed operation of over 120 mW for a 100-/spl mu/m diameter gain region are demonstrated. A quasi-circular far-field pattern with a divergence of about 1/spl deg/ is obtained.>