High contrast atomic magnetometer based on coherent population trapping

We present an experimental and theoretical investigation of the coherent population trapping (CPT) resonance excited on the D1 line of ⁸⁷Rb atoms by bichromatic linearly polarized laser light. The experimental results show that a lin‖lin transition scheme is a promising alternative to the conventional circular–circular transition scheme for an atomic magnetometer. Compared with the circular light transition scheme, linear light accounts for high-contrast transmission resonances, which makes this excitation scheme promising for high-sensitivity magnetometers. We also use linear light and circular light to detect changes of a standard magnetic field, separately.