High-performance millimeter-scale silicon grating emitters for beam steering applications

【摘要】 A 2-mm-long silicon-on-insulator grating emitter with a narrow angular full width at half-maximum（FWHM） and a high sideband suppression ratio（SSR） is proposed and designed. It consists of a Si₃N₄/Si grating with an approximate Gaussian emission profile along the grating length, which aims to reduce the sidelobe intensity of the scanning light in the far-field, thereby improving the resolution of the longitudinal steering resolution of the light detection and ranging（lidar）. Numerical analysis shows that the angular FWHM of the emitted beam could be as low as 0.026° for a grating length of 2.247 mm and the input TE-like waveguide mode at 1550 nm, and the SSR could be more than 32.622 dB. Moreover, this Si₃N₄/Si grating exhibits a favorable fabrication error tolerance when considering the width and length variation of the Si₃N₄overlayer in practice. Our design offers a promising platform for realizing integrated optical phased arrays for the long-distance solid-state lidar.更多还原

【Abstract】 A 2-mm-long silicon-on-insulator grating emitter with a narrow angular full width at half-maximum（FWHM） and a high sideband suppression ratio（SSR） is proposed and designed. It consists of a Si₃N₄/Si grating with an approximate Gaussian emission profile along the grating length, which aims to reduce the sidelobe intensity of the scanning light in the far-field, thereby improving the resolution of the longitudinal steering resolution of the light detection and ranging（lidar）. Numerical analysis shows that the angular FWHM of the emitted beam could be as low as 0.026° for a grating length of 2.247 mm and the input TE-like waveguide mode at 1550 nm, and the SSR could be more than 32.622 dB. Moreover, this Si₃N₄/Si grating exhibits a favorable fabrication error tolerance when considering the width and length variation of the Si₃N₄overlayer in practice. Our design offers a promising platform for realizing integrated optical phased arrays for the long-distance solid-state lidar.更多还原