Light-guide snapshot spectrometer for biomedical applications

We present a proof-of-principle prototype of a fiber-based snapshot spectrometer to provide high spatial and spectral sampling for biomedical application such as cell signaling or diagnostics. An image is collected by a custom fiber bundle and then divided into spatial groups with spaces in between for dispersion. The image is later scaled down by an image taper (to scale down the image size and allow smaller optical components), dispersed with a prism and captured by a CCD camera. An interpolation algorithm is used to locate each wavelength and reconstruct the image for each spectral channel. The fiber bundle is fabricated by aligning multi-mode bare fiber ribbons as matrix, gluing together in Teflon molds, laser cutting and polishing. We present preliminary finger occlusion results obtained with the spectrometer where the oxy- and deoxy-hemoglobin spectrum could be differentiated.