Fig. 1. Optical path diagram of OPA

Fig. 2. Photographs of supercontinuum white light . (a) Supercontinuum white light generated in YVO₄ crystal；(b) supercontinuum white light spot

Fig. 3. Spectrum of supercontinuum white light generated in YVO₄ crystal

Fig. 4. Autocorrelation measurement results of compressed output signals. (a) Central wavelength is 690 nm; 　　(b) central wavelength is 870 nm

Fig. 5. Spectra of tunable output signals

Fig. 6. Energy of tunable output pulse and shortest pulse width after compression

Fig. 7. Long term power stability of OPA output at 690 nm