Electro-absorption modulated tunable V-cavity laser

Abstract

Low-cost tunable lasers are key enablers for wide deployment of dense wavelength division multiplexing (DWDM) technology in upcoming 5G wireless networks. Simple and compact tunable V-cavity laser (VCL) have been previously reported with direct modulation up to 10Gbps. The transmission distance was limited to below 10km due to wavelength chirp and chromatic dispersion of optical fiber in the telecom C-band. Here we present an electro-absorption modulated tunable V-cavity laser (VCL) based on InGaAlAs/InP multiple quantum wells. The modulator is monolithically integrated with the half-wave coupled VCL, which are fabricated with a single shallow etch for ridge waveguides and a single deep etch step for reflecting facets and trenches. No grating nor epitaxial regrowth is required. A deep-etched trench serves as the partial reflecting front mirror for the laser, while providing an excellent electrical isolation between the laser and the modulator. 50-channel wavelength tuning with 100 GHz spacing is achieved, with side-mode suppression ratio as high as 47 dB. Error-free transmission over 50 km is demonstrated at 10 Gbps, with receiver sensitivity better than -23 dBm.