A novel dual-lens-coupling system for DFB laser based on hybrid integration

A dual-lens-integrated distributed feedback (DFB) laser based on hybrid integration for single-mode transmitter optical subassembly (TOSAs) is discussed in this paper. The alignment and fixing of the lenses are simple to manipulate and highly accurate, making it possible to achieve high-efficient optical coupling to single-mode fiber (SMF) without additional high-precision tools and fixing equipment. The capability for a low coupling loss of less than 3 dB between the laser and fiber was demonstrated. The fabricated TOSA module has clear opening eyes with minor time jitters at a bit rate of 25 Gbit/s. This hybrid integration is a low fabrication cost, compact, and low insertion loss method to manufacture TOSA for a 200 or 400 GbE optical transceiver in a high-speed optical network.