A simple imaging solution for chip-scale laser cooling

We demonstrate a simple stacked scheme that enables absorption imaging through a hole in the surface of a grating magneto-optical trap (GMOT) chip, placed immediately below a micro-fabricated vacuum cell. The imaging scheme is capable of overcoming the reduced optical access and surface scatter that is associated with this chip-scale platform, while further permitting both trapping and imaging of the atoms from a single incident laser beam. The through-hole imaging is used to characterise the impact of the reduced optical overlap volume of the GMOT in the chip-scale cell, with an outlook to an optimised atom number in low volume systems.