Integrated Silicon Fourier Transform Spectrometer with Broad Bandwidth and Ultra‐High Resolution

Journal Article · Wed Mar 03 00:00:00 EST 2021 · Laser & Photonics Reviews

DOI:https://doi.org/10.1002/lpor.202000358· OSTI ID:1804543

Li, Ang  ^[1]; Fainman, Yeshaiahu ^[1]

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1. Department of Electrical and Computer Engineering University of California at San Diego La Jolla CA 92093‐0407 USA

Abstract An ultra‐high resolution Fourier transform spectrometer (FTS) realized in silicon photonic platform that can operate with broad band, narrow band as well as a combination of broad band and narrow band signals is reported. The ultra‐high resolution of the spectrometer is achieved by exploiting multiple techniques: a Michelson interferometer (MI) structure to increase the optical path delay (OPD), a hybrid waveguide design to reduce insertion loss, an optimized heater and air trenches to achieve higher thermal efficiency. Moreover, to further increase the OPD of the spectrometer to increase its resolution, a novel multiple interferometers approach is employed which combines balanced MI with N statically imbalanced MIs, thereby increasing the OPD of a single MI by factor of N + 1. An FTS spectrometer consisting of N = 2 such MIs is fabricated and experimentally characterized using unknown broad bandwidth input signal spectra of about 180 nm centered around 1550 nm, a narrow line laser input signal, and a combination of broad and narrow band signals demonstrating spectral resolution of about 0.16 nm.

• Sponsoring Organization: USDOE
• OSTI ID: 1804543
• Journal Information: Laser & Photonics Reviews, Journal Name: Laser & Photonics Reviews Vol. 15 Journal Issue: 4; ISSN 1863-8880
• Publisher: Wiley Blackwell (John Wiley & Sons)
• Country of Publication: Germany
• Language: English