Air-clad silicon pedestal structures for broadband mid-infrared microphotonics

• Main Authors: Lin, Pao Tai (Contributor), Singh, Vivek (Contributor), Cai, Yan (Contributor), Kimerling, Lionel C. (Contributor), Agarwal, Anuradha Murthy (Contributor)
• Other Authors: MIT Materials Research Laboratory (Contributor), Massachusetts Institute of Technology. Department of Materials Science and Engineering (Contributor)
• Format: Article
• Language: English
• Published: Optical Society of America, 2013-07-30T18:31:10Z.
• Subjects: Article
• Online Access: Get fulltext

 Toward mid-infrared (mid-IR) silicon microphotonic circuits, we demonstrate broadband on-chip silicon structures, such as: (i) straight and bent waveguides and (ii) beam splitters, utilizing an air-clad pedestal configuration which eliminates the need for typical mid-IR-lossy oxide cladding. We illustrate a sophisticated fabrication process that can create high-quality pedestal structures in crystalline silicon, while preserving its mid-IR transparency. A fundamental waveguide mode is observed between λ = 2.5  μm and λ = 3.7  μm, and an optical loss of 2.7  dB/cm is obtained at λ = 3.7  μm. Our pedestal silicon structures show 50∶50 mid-IR power splitting enabling the further development of mid-IR silicon microphotonics.