Subwavelength grating waveguide antenna based on interleaved groove structure

Abstract

Integrated optical antennas are essential components of optical phased arrays for applications in light detection and ranging technology. To achieve larger detection distances, wider detection ranges, and higher scanning resolutions, it is imperative to employ millimeter-scale or longer effective lengths to achieve a narrow beam width, coupled with high radiation efficiency. In the high refractive index contrast silicon photonics platform, achieving a narrow far-field beam width and high radiation efficiency simultaneously is a formidable challenge. In the article, a subwavelength grating waveguide antenna with interleaved grooved lateral radiating block arrays is proposed. The simulation result shows that an effective length of about 3.3 mm is attained, with a corresponding far-field beam width is 0.02°, and a radiation efficiency of 0.785 at the wavelength of 1550 nm. It is also found that the crosstalk between the adjacent grating antennas designed in the range of 1.49 μm ∼ 1.61 μm is less than −15.6 dB.