Efficient Light Collection and Direction-of-Arrival Estimation Using a Photonic Integrated Circuit

Efficient collection of light into a photonic integrated circuit is becoming increasingly important. To couple light from free-space into an integrated circuit, one needs to efficiently guide it into a photonic wire. By using multiple light capturing elements and tuning their respective phases, it is possible to efficiently guide light into a single-mode waveguide, even when the phase front is distorted. Using a similar approach, a direction-of-arrival estimation is also performed. This is useful in free-space optical links or wavefront analysis. A 16 element integrated structure that performs these functions is presented here. Increasing the number of elements and downscaling the size will further improve the performance.