Backward-Emitting Silicon Nitride Optical Phased Array Enabling Efficient Wavelength-Tuned Beam Steering

IEEE Photonics Journal

Taehoon Kim¹  Bishal Bhandari²  Sang-Shin Lee²  Chul-Soon Im²  Min-Cheol Oh³  Sung-Moon Kim³  Kyeong-Pyo Lee⁴ 

[1] Agency for Defense Development, Daejeon, South Korea;Department of Electronic Engineering, Kwangwoon University, Seoul, South Korea;Department of Electronics Engineering, Pusan National University, Pusan, (Busan), South Korea;i3system, Daejeon, South Korea;

关键词: Optical phased array;    light detection and ranging;    silicon nitride photonics;   

DOI  :  10.1109/JPHOT.2020.3019060

来源: DOAJ

【 摘 要 】

Silicon nitride (SiN) optical phased arrays (OPAs) have emerged as a potential alternative to their silicon counterparts, due to their potential use in enhanced solid-state light detection and ranging. Grating antennas based on a SiN waveguide suffer from a limited beam steering efficiency, owing to the relatively lower effective refractive index of the waveguide. To mitigate this limitation, we propose and demonstrate a backward-emitting SiN OPA incorporating a reinforced grating vector, which provides efficient wavelength-tuned beam steering along the longitudinal direction. Two backward-emitting OPAs were primarily characterized by their steering efficiency and the spectral emission for the main lobe, and they were compared with a forward-emitting device using a weakened grating vector. The results indicated that strengthening the grating vector for the antenna improved the beam steering efficiency but adversely affected the dependence of its directionality on the wavelength. The directionality was particularly inspected, with respect to major design parameters for the grating antennas, including the pitch and etch depth of a SiN grating, as well as the thickness of a buried oxide and SiN core layer. The proposed backward-emitting OPA scheme is expected to significantly promote its feasibility as an advanced beam scanning device.

【 授权许可】

Unknown