Low-Threshold 795 nm Oxide-Confined Distributed Feedback Lasers With Surface Gratings

795 nm oxide-confined distributed feedback (DFB) lasers have been developed. The oxide-confined structure is used to realize lateral optical and current confinement, and the first-order surface gratings offer the frequency selectivity for single-longitudinal mode operation. The fabricated 200-mu m-long devices exhibited a low-threshold current of similar to 4.8 mA, a 3-dB modulation bandwidth of similar to 5.8 GHz and maintained stable single mode operation around 795 nm with side mode suppression ratio (SMSR) as high as similar to 40 dB. The simple and compact laser structure greatly reduces the difficulty of device design and fabrication compared with traditional DFB lasers. The characteristics of the laser, including low-threshold current, singlemode stability and potentially narrow spectral linewidth, make it a suitable candidate for applications in absorption spectroscopy of the rubidium D1 line, chip-scale atomic clocks, magnetometers, and gyroscopes.