Laser cooling in a chip-scale platform

Chip-scale atomic devices built around micro-fabricated alkali vapor cells are at the forefront of compact metrology and atomic sensors. We demonstrate a micro-fabricated vapor cell that is actively pumped to ultra-high-vacuum (UHV) to achieve laser cooling. A grating magneto-optical trap (GMOT) is incorporated with a 4 mm-thick Si/glass vacuum cell to demonstrate the feasibility of a fully miniaturized laser cooling platform. A two-step optical excitation process in rubidium is used to overcome surface-scatter limitations to the GMOT imaging. The unambiguous miniaturization and form-customizability made available with micro-fabricated UHV cells provide a promising platform for future compact cold-atom sensors.