Optical phased arrays (OPAs) are a solid-state device able to manipulate the distribution of optical power without the use of mechanical beam steering systems and have potential applications in free-space laser communications, target acquisition and tracking, and interferometry. Here we present a scalable OPA and digital control architecture capable of steering a laser beam at MHz frequencies, and having arbitrary control over the beam wavefront.
We present a continuous wave Light Detection And Ranging (LiDAR) sensor that instantaneously measures distance and radial velocity with strong immunity to interference (e.g., other LiDAR sensors, glare). By automatically prioritising measured information based on velocity and range, our aim is to reduce the processing time required to execute safety-critical decisions in autonomous applications.
We present the preliminary design and experimental results of a 1550 nm solid-state beam pointing system based on an optical phased array (OPA) architecture. OPAs manipulate the distribution of optical power in the far-field by controlling the phase of individual emitters in an array. This allows OPAs to steer the beam in the far field without any mechanical components (e.g., steering mirrors). The beam-steering system presented here uses waveguide electro-optic modulators to actuate the phase of each element in a 7-emitter OPA, enabling kHz bandwidth steering with sub-milliradian pointing precision. The control system used to stabilize and control the phase of each emitter in the OPA exploits a technique called digitally enhanced heterodyne interferometry, allowing the phase of each emitter to be measured simultaneously at a single photodetector, dramatically simplifying the optical system. All digital signal processing is performed using a field-programmable gate-array. Applications of this technology include free-space link acquisition and tracking for satellite-to-satellite laser communications and light detection and ranging (LiDAR).