Multi-grating spectrograph and method of changing gratings
AssigneeOriel Corporation
InventorsZbigniew Drozdowicz, Traian Manta
Life of this patent
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Abstract
An improved multiple grating spectrograph is provided comprising a grating changer for mounting gratings, and rotatable about an axis substantially perpendicular to grating lines such that changing from one grating to another preserves the wavelength-selecting angle of incidence of electromagnetic radiation. The grating changer preferably includes a grating holder, and an actuator for moving the holder about the axis.
Claims20
A spectrograph for analyzing a source of electromagnetic radiation comprising:
- at least two diffraction gratings having a plurality of lines;
- a grating holder for removably, replaceably mounting said diffraction gratings;
- an actuator for moving said grating holder about a first axis to change which of said diffraction gratings is exposed to radiation from the source;
- and
- a plate rotatable around a second axis, said grating holder connected for rotation with said plate, said second axis aligned substantially parallel to the plurality of diffraction grating lines such that rotation of said plate changes the angle of incidence at which radiation from the source strikes said diffraction grating;
- said first axis substantially perpendicular to the lines on said gratings such that operation of said actuator to change said diffraction grating does not unnecessarily change the wavelength-selecting angle of incidence.
A grating changer for a spectrograph including at least two diffraction gratings, the changer comprising:
- a grating holder having at least two sides and mounted to a shaft for rotation about a first axis, the diffraction gratings mounted to sides of said holder such that lines of the gratings are aligned substantially perpendicular to the first axis;
- an actuator operably connected to the shaft for rotating said holder to change the diffraction grating in a position aligned with the path of a beam of electromagnetic radiation while preserving the angle of incidence between the beam and a direction substantially parallel to the first axis.
In a multiple grating spectrograph of the type including at least two diffraction gratings having a plurality of lines, a grating changer for mounting said gratings, and a plate rotatable about a first axis, said changer connected for rotation with said plate to change the angle of incidence at which radiation from an electromagnetic source strikes said grating, the improvement comprising said grating changer rotatable about a second axis substantially perpendicular to the grating lines and the first axis such that changing from one grating to another grating does not change the angle of incidence.
A method of changing a diffraction grating in a spectrograph comprising the steps of:
- providing at least two diffraction gratings having a plurality of lines;
- providing a grating holder for mounting the diffraction gratings;
- and
- rotating the holder about an axis substantially perpendicular to the grating lines;
- whereby the grating may be changed without altering an angle between incident electromagnetic radiation and the axis.
Dependencies are inferred from the claim text.