Fig. 1. Schematic of the experimental device

Fig. 2. Photo of experimental device

Fig. 3. Reflection and transmission spectra of seed grating used in the experiment

Fig. 4. Transmission spectrum of regenerated grating at 900 ℃

Fig. 5. Variation of central wavelength during the temperature rising and falling processes. (a) Cooling; (b) heating

Fig. 6. Average central wavelength versus temperature

Fig. 7. Change of output laser intensity with central wavelength. (a) Cooling process;(b) heating process

Fig. 8. Evolution of intensity with wavelength in temperature rising and falling processes under input current of 150 mA. (a) Cooling to 800 ℃; (b) cooling to 800 ℃; (c) heating to 300 ℃; (d) heating to 800 ℃

Fig. 9. Change of laser intensity and central wavelength tested for a long time under 700 ℃. (a) Variation of laser intensity and central wavelength; (b) output spectra of laser under different time