Fig. 1. (a) Schematic of integrated external cavity laser device; (b) butterfly packaged device

Fig. 2. Characteristics of the external cavity semiconductor laser based on polarization-maintaining FBG. (a) PI curve; (b) output spectrum

Fig. 3. Current and temperature tuning characteristics of the prototype device. (a) Frequency-current; (b) frequency-temperature

Fig. 4. Measured spectra with different working currents

Fig. 5. Measured frequency noise PSDs with different working currents

Fig. 6. Measured RIN of laser

Fig. 7. Measured frequency and power stability of laser