Thermal Tunable Narrow Linewidth External Cavity Laser With Thermal Enhanced FBG

We demonstrated a mode-hop-free external cavity laser (ECL) design incorporating a semiconductor gain chip and a fiber Bragg grating (FBG) with enhanced thermal sensitivity. The compact ECL features a narrow linewidth of 35 kHz and a high linear thermal tuning velocity of 65 pm/°C (8.125 GHz/°C), which is six times higher than that of normal FBG-based ECLs.