Fig. 1. Schematic diagram of experimental setup

Fig. 2. DFL output spectra when pump current is 14.5 A. (a) 5 ℃-65 ℃; (b) 60 ℃

Fig. 3. Variations of (a) center wavelength and (b) frequency difference between left and right peaks with temperature when pump current is 14.5 A

Fig. 4. (a) Small signal gain curve of Nd∶YVO4 microchip crystal; (b) variation of laser output power with temperature when pump power is 14.5 A; small signal gain curves and DFL spectra when temperature is (c) T2 and (d) T3, respectively