Vector magnetometer based on the effect of coherent population trapping.

The method is presented for converting a coherent population trapping (CPT) atomic clock into a CPT vector (compass-) magnetometer without mechanically moving parts through a relatively simple add-on. The system of 3D Helmholtz coils was used for compensation of the external magnetic field, allowing measurement of both strength and direction of a magnetic field at the sensitivity level of -/ within a 10-Hz bandwidth. Angular resolution of the developed vector magnetometer amounts to about 10 degrees.

Soliton based χ combs in high-Q optical microresonators.

Investigations of the frequency combs in χ microresonators have passed a critical point when the soliton based regimes are well established and realized on different platforms. For χ microresonators, where the first harmonic (FH) and second harmonic (SH) envelopes are coupled via the SH generation and optical parametric oscillation, the comb-soliton studies are just starting. Here we report on a vast accessible dual χ soliton-comb family in high-Q microresonators with the SH and FH combs centered at the pump frequency ω and its half ω/2.