Abstract:
A multiband spatial heterodyne spectrometer for determining spectra in first and second wavelength bands has a beamsplitter configured to split incident light and to direct the incident light upon a first and a second diffraction grating. The gratings are configured for Littrow reflection of incident light of the first wavelength band at a first order and Littrow reflection of incident light of the second wavelength band at a second order. Light reflected by the first and the second diffraction grating forms diffraction patterns imaged by an electronic camera. A dispersive device separates the imaged interference patterns onto separate groups of pixel sensors corresponding to the wavelength bands. A processing device receives information from the detector and computes spectra therefrom. The second diffraction grating is split spatially or temporally to provide two different responses, so the system can disambiguate spectra. In embodiments, the spectrometer computes hyperspectral images of a target.
Abstract:
Light dispersing device comprising a slit element having a slit for exposure to electromagnetic radiation, wherein the slit element is configured and disposed for turning the slit between at least two positions. The light dispersing device is used together with a streak camera, whereby in a first position the slit is adjusted to influence the temporal resolution of the streak camera and in a second postion the slit is adjusted to influence the spectral resolution of the streak camera.
Abstract:
A spectrometer measures a spectrum of a light beam supplied from a light source so as to obtain fine information and coarse information of the spectrum easily. This spectrometer has a holographic grating, an Echelle grating, a rotation stage and a line sensor. In the case where a single pass beam is to be detected, a control processing unit controls the rotation stage so as to rotate the Echelle grating from the Littrow arrangement by a predetermined angle &dgr;1. On the other hand, in the case where a double pass beam is to be detected, the control processing unit controls the rotation stage so as to rotate the Echelle grating from the Littrow arrangement by a predetermined angle &dgr;2.