Planar-Optics Based Light Delivery System for Magneto-Optical Traps And Method For Using The Same

An apparatus for light delivery to magneto-optical trap (MOT) system utilizes only planar optical diffraction devices including a planar-integrated-circuit PIC and a metasurface MS. When MOT is based on the use of a diffraction grating, a grating chip is additionally employed to launch and manipulate light for laser cooling. Bridging the gap between the sub-micrometer-scale guided mode on the PIC and the centimeter-scale beam needed for laser cooling, a magnification of the mode area by about 10.sup.10 is demonstrated using an on-chip extreme-mode-converter to launch a Gaussian mode into free space from a PIC-waveguide and a beam-shaping, polarization-dependent MS to form a diverging laser beam with a flat-top spatial profile, which efficiently illuminates the grating chip without loss of light. Comparison to equivalent Gaussian-beam-illuminated GMOTs evidences advantageous power efficiency of operation of the proposed light delivery system as compared with conventional systems employing Gaussian distribution of illumination at the grating chip.