Large Bandwidth Fluorescence Spectrum in Situ Sensing Chip Based on Antisymmetric AWG Design

An on-chip spectrometer with 160nm bandwidth, 10nm interval, and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.4\text{mm}^{*}0.5 \text{mm}$</tex> area was fabricated by designing an anti symmetric AWG (Array Waveguide Grating) structure on the silicon nitride platform. The wideband fluorescence spectral signal in the waveguide could be separated by the spectrometer, and the fluorescence spectral signal in the sensing process could be detected in real-time. Finally, excitation and collection of fluorescent materials and in situ sensing of fluorescence spectra can be realized only by single-layer structure on passive silicon nitride chips, which greatly expands the application of fluorescent materials on chips.