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arXiv · 2112.01961

Mid-infrared Fourier-transform spectrometer based on metamaterial lateral cladding suspended silicon waveguides

Thi Thuy Duong Dinh·Xavier Le Roux·Natnicha Koompai·Daniele Melati·Miguel Montesinos-Ballester·David González-Andrade·Pavel Cheben·Aitor V. Velasco·Eric Cassan·Delphine Marris-Morini·Laurent Vivien·Carlos Alonso-Ramos
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Abstract

Integrated mid-infrared micro-spectrometers have a great potential for applications in environmental monitoring and space exploration. Silicon-on-insulator (SOI) is a promising platform to tackle this integration challenge, due to its unique capability for large volume and low-cost production of ultra-compact photonic circuits. However, the use of SOI in the mid-infrared is restricted by the strong absorption of the buried oxide layer for wavelengths beyond 4 μm. Here, we overcome this limitation by utilizing metamaterial-cladded suspended silicon waveguides to implement a spatial heterodyne Fourier-transform (SHFT) spectrometer operating near 5.5μm wavelength. The metamaterial-cladded geometry allows removal of the buried oxide layer, yielding measured propagation loss below 2 dB/cm between 5.3μm and 5.7μm wavelengths. The SHFT spectrometer comprises 19 Mach-Zehnder interferometers with a maximum arm length imbalance of 200 μm, achieving a measured spectral resolution of 13cm-1 and a free-spectral range of 100 cm-1 near 5.5μm wavelength.

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Thi Thuy Duong Dinh, Xavier Le Roux, Natnicha Koompai, Daniele Melati, Miguel Montesinos-Ballester, David González-Andrade, Pavel Cheben, Aitor V. Velasco, Eric Cassan, Delphine Marris-Morini, Laurent Vivien, Carlos Alonso-Ramos. 2021-12-03. Mid-infrared Fourier-transform spectrometer based on metamaterial lateral cladding suspended silicon waveguides. https://arxiv.org/abs/2112.01961

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