High sampling, waveguide-based snapshot imaging spectrometer enabled by 2-photon polymerized additive manufacturing

We present a novel high spatial sampling snapshot imaging spectrometer, realized through a cladded waveguide array fabricated using 2-photon polymerization (2PP) additive manufacturing. The snapshot imaging is achieved by managing the density of input vs output of the waveguide array. The input features a densely packed input array, while the output of the array is designed with specific void spaces to provide space for spectral data. Specifically, this waveguide structure is based on an array of 45000 (e.g. 300 x 150 structures) waveguides with an input 3 µm pitch, utilizing square waveguide with a 1.7 µm core. The fabricated waveguide array is then integrated into an imaging spectrometer, allowing about 40 spectral channels. To validate the performance of the system, we conducted imaging tests using a resolution (USAF) and fluorescence test targets (Thermofisher microscopic cell and tissue slides) and ultimately imaged multi-probe cell signaling samples (like diabetic inlet cells). Spectral comparisons were performed against commercial spectrometer systems. Additionally, the results of air-cladded waveguide array and unpolymerized IP-S cladded array are being compared.