Mid-infrared Fourier-transform spectrometer based on metamaterial lateral cladding suspended silicon waveguides Journal Articles uri icon

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  • 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, owing 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 at wavelengths near 5.5 µm. The metamaterial-cladded geometry allows removal of the buried oxide layer, yielding measured propagation loss below 2 dB/cm at wavelengths between 5.3 and 5.7 µm. The SHFT spectrometer comprises 19 Mach–Zehnder interferometers with a maximum arm length imbalance of 200 µm, achieving a measured spectral resolution of 13 cm−1 and a free spectral range of 100 cm−1 at wavelengths near 5.5 µm.


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

publication date

  • February 15, 2022