Compact optical pumping system based on offaxis freeform mirror collimation for miniaturized atomic gyroscopes

Conventional optical systems for laser beam expansion, collimation, and reflective path configurations in miniaturized atomic gyroscopes face challenges due to excessive volume and component complexity, limiting further optical integration. To overcome this, we propose a compact optical architecture using an off-axis freeform mirror that integrates beam expansion, collimation, and reflection for vertical-cavity surface-emitting lasers (VCSELs) into a single freeform surface. We fabricated an off-axis freeform reflective mirror and a total internal reflection mirror, both achieving polarization preservation above 98%. This approach offers a promising solution for miniaturizing atomic sensors.