Electroabsorption-Modulated DFB Laser Integrated With Dual-Core Spot-Size Converters

A 1.55-mum single shallow ridge electroabsorption- modulated distributed feedback laser that is monolithically integrated with a buried-ridge-stripe dual-core spot-size converter (SSC) at the input and output ports was fabricated by combining selective area growth, quantum-well intermixing, and dual-core integration techniques simultaneously. These devices exhibit a threshold current of 34 mA, a side mode suppression ratio of 38.0 dB, a 3-dB modulation bandwidth of 11.0 GHz, and a modulator extinction ratio of 25.0 dB dc. The output beam divergence angles of the SSC in the horizontal and vertical directions are as small as 7.3deg times 18deg, respectively, resulting in 3.2-dB coupling loss with a cleaved single-mode optical fiber.