Imaging spectrometer

摘要

Optical radiation from a sample is received by the slit and it is passed through an aperture in a reflective plane of a folding mirror towards a curved reflective surface of a collimating mirror. The slit and the curved reflective surface have a common optical axis. The reflective plane and the curved reflective surface face each other. The optical radiation passed through the folding mirror is collimated by the curved reflective surface. The collimated optical radiation is directed to the reflective plane of the folding mirror by the curved reflective surface. The collimated optical radiation is reflected in a direction other than the common optical axis of the slit and the curved reflective surface by the reflective plane.

主权项

1. An imaging spectrometer that acquires a spectrally-resolved image of an object or scene comprising:
an optical collimating system comprising an elongated slit, the elongated slit having a length and a height, the length being larger than the height, a folding mirror comprising a reflective plane, and a collimating mirror comprising a curved reflective surface, the reflective plane of the folding mirror and the curved reflective surface of the collimating mirror being set to face each other, the folding mirror being configured to allow optical radiation received by the slit to pass through the folding mirror towards the curved reflective surface of the collimating mirror, the slit and the curved reflective surface having a common optical axis, the curved reflective surface being configured to collimate the optical radiation coming from the slit and direct the collimated optical radiation to the reflective plane of the folding mirror, the reflective plane being configured to reflect the collimated optical radiation in a direction other than the common optical axis of the slit and the curved reflective surface; a dispersive imaging element; and a two-dimensional detecting element, the reflective plane being configured to reflect the collimated optical radiation to the dispersive imaging element, the dispersive and imaging element being configured to form a location dependent spectrum of the received optical radiation on the two-dimensional detecting element, the two-dimensional detecting element being configured to transform the location dependent spectrum to an electrical signal for processing data in the electrical signal, wherein the dispersive and imaging element is configured to receive the collimated optical radiation formed by the collimating mirror, and the dispersive and imaging element comprising at least one prism, at least one transmission grating, and at least one lens, each of the at least one prism, at least one transmission grating, and at least one lens being a transmissive component, the at least one lens being on-axis with the at least one prism, the at least one lens being disposed after the at least one prism in a direction of propagation of the optical radiation, thereby enabling reduction of smile and Keystone caused by the at least one prism.