Fourier transform spectrometer on silicon with thermo-optic non-linearity and dispersion correction

Author(s)

Souza, Mario C. M. M. ^[1] ; Grieco, Andrew ^[2] ; Frateschi, Newton C. ^[1] ; Fainman, Yeshaiahu ^[2]

Affiliation

^[1] Univ Estadual Campinas, Gleb Wataghin Phys Inst, BR-13083970 Campinas, SP - Brazil

^[2] Univ Calif San Diego, Dept Elect & Comp Engn, 9500 Gilman Dr, San Diego, CA 92023 - USA

• Document type: Journal article
• Source: NATURE COMMUNICATIONS; v. 9, FEB 14 2018.
• Web of Science Citations: 9

Abstract

Miniaturized integrated spectrometers will have unprecedented impact on applications ranging from unmanned aerial vehicles to mobile phones, and silicon photonics promises to deliver compact, cost-effective devices. Mirroring its ubiquitous free-space counterpart, a silicon photonics-based Fourier transform spectrometer (Si-FTS) can bring broadband operation and fine resolution to the chip scale. Here we present the modeling and experimental demonstration of a thermally tuned Si-FTS accounting for dispersion, thermo-optic non-linearity, and thermal expansion. We show how these effects modify the relation between the spectrum and interferogram of a light source and we develop a quantitative correction procedure through calibration with a tunable laser. We retrieve a broadband spectrum (7 THz around 193.4 THz with 0.38-THz resolution consuming 2.5W per heater) and demonstrate the Si-FTS resilience to fabrication variations - a major advantage for large-scale manufacturing. Providing design flexibility and robustness, the Si-FTS is poised to become a fundamental building block for on-chip spectroscopy. (AU)

• FAPESP's process: 15/20525-6 - Active devices exploiting capacitively-inducedc free-carrier effects in silicon waveguides
• Grantee: Mário César Mendes Machado de Souza
• Support type: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 14/04748-2 - Coupled microresonators applied to signal processing and photonics integration
• Grantee: Mário César Mendes Machado de Souza
• Support type: Scholarships in Brazil - Doctorate