Integrated Electro-Optically Tunable Narrow-Linewidth III–V Laser

Abstract

Herein, an integrated electro-optically tunable narrow-linewidth III–V laser with an output power of 738.8 μW and an intrinsic linewidth of 45.55 kHz at the C band is demonstrated. The laser cavity is constructed using a fiber Bragg grating (FBG) and a tunable Sagnac loop reflector (TSLR) fabricated on thin-film lithium niobate. The combination of the FBG and the electro-optically tunable TSLR offers the advantages of single spatial mode, single frequency, narrow linewidth, and wide wavelength tunability for the electrically pumped hybrid integrated laser, which features a frequency tuning range of 20 GHz and a tuning efficiency of 0.8 GHz V⁻¹.