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Integrated phased array for wide-angle beam steering

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Integrated phased array for wide-angle beam steering

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We demonstrate an on-chip optical phased array fabricated in a CMOS compatible process with continuous, fast (100 kHz), wide-angle (51°) beam-steering suitable for applications such as low-cost LIDAR systems. The device demonstrates the largest (51°) beam-steering and beam-spacing to date while providing the ability to steer continuously over the entire range. Continuous steering is enabled by a cascaded phase shifting architecture utilizing, low power and small footprint, thermo-optic phase shifters. We demonstrate these results in the telecom C-band, but the same design can easily be adjusted for any wavelength between 1.2 and 3.5 μm.
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... With the growing interest from the research community in chip-scale LiDAR, beam steering based on the integrated optical phased array (OPA) has drawn a lot of research effort in the past decade [9]. Significant progress has been achieved, including thermal tuning [10][11], electro-optics tuning [12], high sensitivity wavelength tuning [13][14], integrated on-chip light source [8,15], and side lobe suppression by aperiodic or apodized array placement [21][22][23]. However, most onchip OPA research stays in the single-waveguide-layer structure [9][10][11][12][13][14][15][16][17][18][19][20][21]. ...
... Significant progress has been achieved, including thermal tuning [10][11], electro-optics tuning [12], high sensitivity wavelength tuning [13][14], integrated on-chip light source [8,15], and side lobe suppression by aperiodic or apodized array placement [21][22][23]. However, most onchip OPA research stays in the single-waveguide-layer structure [9][10][11][12][13][14][15][16][17][18][19][20][21]. The OPA formed by a single layer can only emit the beam by diffractive components such as grating couplers, which has narrowband and relatively low emitting efficiency. ...
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... Although as expected the full width half maximum of the beam widens as it goes away from the boresight and is doubled at ±57.5 o . The residual sidelobes apparent in the plots above are due to the limitation in the accurate phase manipulation of the integrated phase shifters and the phase uncertainty present in each corresponding waveguiding antenna [15,16]. ...
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