Dual frequency laser for dual mode optical lattice atomic clock

A dual frequency laser for a dual mode optical lattice atomic clock, wherein the dual frequency laser comprises a 532 nm pump laser source, and in an emission optical path of the 532 nm laser, a beam splitter set, a dichroic mirror, a titanium sapphire crystal, a birefringent crystal, an electro-optic crystal, a concave reflector, and piezoelectric ceramics (PZT) are disposed sequentially, wherein

• the dichroic mirror and the concave reflector form a first resonant cavity configured to generate a laser;
• the beam splitter set is configured to split a collimated pump beam into two pump beams that are spatially separated;
• an optical axis of the birefringent crystal is at an angle of 45° to a light incidence plane to generate propagation paths for ordinary ray and extraordinary ray within the same cavity to form two eigen modes;
• in each of the propagation paths for ordinary ray and extraordinary ray, a set of birefringent filter and etalon is provided, an anti-reflective coating of the birefringent filter and a high-reflective coating of the concave reflector have spectral bands with overlapping edges, the spectral bands being used for a rough selection of a laser wavelength, and the etalon and the birefringent filter being used for a mode fine selection;
• the electro-optic crystal is configured to add an electric field externally in a direction parallel to an electric vector of the ordinary ray or an electric vector of the extraordinary ray to independently regulate a frequency of one polarized ray;
• and
• the piezoelectric ceramic is combined with the electro-optic crystal to regulate two laser frequencies simultaneously.