A continuous-wave all-solid-state tunable Ti：sapphire laser with compact configuration is presented. The frequency-tuning range extends from 760 to 825 nm by rotating the birefringent filters. When the intracavity etalon is locked on tile oscillating frequency of the laser and the length of the resonator is scanned by the piezo- electric ceramics transducer, a maximal continuous frequency-tuning range of 15.3 GHz is realized. The obtained Ti：sapphire laser is successfully applied to scan the saturation absorption spectroscopy of D1 transitions of SrRb atoms around the wavelength of 794.97 nm.
A scheme for measuring the intra-cavity round-trip loss of an all-solid-state single-frequency laser by inserting a type-I noncritical phase-matching nonlinear crystal introducing nonlinear loss into the resonator is presented.The intra-cavity round-trip loss is theoretically deduced by analyzing the dependence of the fundamental-wave（FW） and second-harmonic-wave（SHW） powers on the pump factor and the nonlinear conversion factor of the single-frequency laser and experimentally measuring them by recording different FW and SHW powers, which are decided by the temperature of the nonlinear crystal. The measured intra-cavity round-trip loss and pump factor are 4.84% and 6.91% W-1, respectively. The standard deviations of the measured intra-cavity round-trip loss and the pump factor are 0.26% and 0.07%, respectively. This scheme is very suitable for measuring the intra-cavity round-trip loss of a high-gain solid-state single-frequency laser.
We present a stable entangled light source that integrates the pump laser, entanglement generator, detectors, and electronic control systems. By optimizing the design of the mechanical elements and the optical path, the size of the source is minimized, and the quantum correlations over 6 d B can be directly provided by the entangled source. The compact and stable entangled light source is suitable for practical applications in quantum information science and technology. The presented protocol provides a useful reference for manufacturing products of bright entangled light sources.
