Nonmagnetic VCSEL package and driver circuit for SERF atomic magnetometer

SERF (Spin-exchange relaxation free) atomic magnetometers have been demonstrated as the ultra-high sensitive, noncryogenic sensor. Single-beam configured sensors often choose VCSEL (Vertical-Cavity Surface-Emitting Laser) as the optical source. The existing commercial VCSELs are often with magnetic package and heater, which will affect the sensitivity of atomic magnetometers. In our work, we presented a novel nonmagnetic VCSEL package and its driver circuit. VCSEL chip, heater, and PT1000 are assembled on FPC (Flexible Printed Circuit), and its driver are optimized in terms of low noise, safe protection and AC temperature control. The result showed that the magnetic field generated by heating current can be ignored based on proposed layout method, and the RMS noise of current and temperature are lower than 0.1 µA and 20 mK, respectively. Our proposed method will expand the possibility for commercialization process of miniature SERF atomic magnetometers.