A Hybrid Integrated Light Source on a Silicon Platform Using a Trident Spot-Size Converter

• Published in: Journal of lightwave technology Vol. 32; no. 7; pp. 1329 - 1336
• Main Authors: Hatori, Nobuaki, Shimizu, Takanori, Okano, Makoto, Ishizaka, Masashige, Yamamoto, Tsuyoshi, Urino, Yutaka, Mori, Masahiko, Nakamura, Takahiro, Arakawa, Yasuhiko
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Circuit properties; Couplings; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Hybrid integration; Integrated optics. Optical fibers and wave guides; inter-chip optical interconnects; Lasers; Light sources; light sources on silicon platform; Loss measurement; Miscellaneous; Optical and optoelectronic circuits; Optical device fabrication; Optical losses; Optical sources and standards; Optical waveguides; Optics; Physics; quantum dot laser; Quantum dots; Semiconductor lasers; laser diodes; Silicon; silicon optical interposer; silicon photonics; spot-size converter; Performance evaluation; Integrated optics; Light source; light sources on silicon platform; Tapered waveguide; Quantum dot; Output power; Hybrid integrated circuit; High density; silicon optical interposer; spot-size converter; High temperature; Spot size; Waveguide; Planar form; quantum dot laser; Accuracy; Hybrid integration; inter-chip optical interconnects; Quantum well lasers; Converter; silicon photonics; Optical interconnection
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2014.2304305

This paper reports a hybrid integrated light source fabricated on a Si platform using a spot-size converter (SSC) with a trident Si waveguide. Low-loss coupling for 1.55 μm and 1.3 μm wavelengths was achieved with merely the simple planar form of a Si waveguide with no use of complicated structures such as vertical tapers or an extra dielectric core overlaid on the waveguide. The coupling loss tolerance up to a 1 dB loss increase was larger than the accuracy of our passive alignment technology. The coupling efficiency was quite robust against manufacturing variations in the waveguide width compared with that of a conventional SSC with an inverse taper waveguide. A multi-channel light source with highly uniform output power and a high-temperature light source were fabricated with a 1.55 μm quantum well laser and a 1.3 μm quantum dot laser, respectively. The integration scheme we report can be used to fabricate light sources for high-density, multi-channel Si optical interposers.