Arbitrary 3D Beam Delivery from Planar Optical Waveguides for Quantum Technology

Grating couplers are an essential component to integrate planar photonics into trapped ion or cold atom quantum devices for optical beam delivery and readout. While etched gratings have been investigated for this before, they exhibit small-scale inconsistencies which can lead to phase errors and background scattered light. To reduce these errors, holographic UV written waveguides and gratings can be used. Here we design such gratings for light delivery from a chip to a target position in free space with arbitrary beam shapes in 3D, which can be optimised e.g. for coupling to individual particles or uniformly across a cloud of particles.