Fluorescence microscopy with a coded aperture snapshot spectral imager

This paper describes the application of a dual-dispersive (DD) coded aperture snapshot spectral imager (CASSI) to fluorescence microscopy. CASSI records an interleaved spatially varying, spectrally filtered map of an object onto a two-dimensional (2D) focal plane. Using a compressive sensing framework, the spectrally encoded 2D scene is reconstructed into a three-dimensional (3D) data cube. CASSI also records a 3D dataset at video rate making it suitable for dynamic cellular imaging. A convex optimization technique combining least squares QR factorization with a total variance constraint is used to reconstruct the image. The system records 32 spectral channels that span the spectral range between 450nm and 750nm with 10nm spectral resolution for any pixel in a 2D image. This paper illustrates the application of CASSI imaging to fluorescence microscopy applications. We report on the reconstruction of fluorescent microspheres used in fluorescence microscopy as calibration standards. Images are compared with a multi-spectral confocal system.