The Research Of The Holographic Concave Grating With Large Relative Aperture Used In The Testing Of Ramman Spectra

With the ability of imaging and dispersion, the holographic concave grating can give a flat-field image, which can be captured by linear sensor easily. So it is used in flat-field spectrometer widely.Based on the holographic concave grating theory, a theory for the flat-field holographic concave grating on aspherical substrate is given. By comparing these two theories, it is find that the holographic concave grating on aspherical substrate can correct more aberration than a holographic concave grating on spherical substrate. And a higher resulotion can be achieved by the flat-field spectrometer with a holographic concave grating on aspherical substrate.A flat-field holographic concave grating on aspherical substrate with a large relative aperture is designed for testing of Ramman spectra by using the software of ZEMAX. And the spot diagram given by ZEMAX shows the advantage of the flat-field spectrometer with holographic concave grating on aspherical substrate.A flat-field holographic concave grating with a large relative aperture is given to build a flat-field spectrometer in this paper. The test of resolution of the spectrometer is finished. A Ramman spectra testing system assembled with a flat-field spectrometer and a holographic notch filter is introduced. The...