Broadband transmission Raman measurements using a field-widened spatial heterodyne Raman spectrometer with mosaic grating structure

A field-widened spatial heterodyne Raman spectrometer with a mosaic grating structure is developed for the simultaneous sensitivity enhancement and broadband transmission Raman measurements. We optimize the etendue to maximize the signals collected from the samples by using field-widening prisms and employ two mosaic gratings to achieve broadband operation, covering 5638 cm(-1) with 2.865 cm(-1) spectral resolution. The signal-to-noise ratios are unproved by a factor of more than 11 and show a good stability and fair repeatability. We investigate the effects of the sample thickness and outer layer depth and observe liquids, solids, mixed targets, and anti-Stokes shifts. The instrument exhibits good performance for wide-field, high-resolution broadband transmission Raman measurements. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement