Back to results
US 8,749,781 B2Granted
High resolution slit-free direct-viewing multiplexing field spectrograph
OwnerRonald Anthony Mastersinventor
Life of this patent
Estimating the term…
Abstract
A compact field spectrograph is described that provides a resolution of 500 or more with no entrance aperture, providing for substantial gain in light throughput, ideal for viewing multiple distant objects with or without telescopic aid, and providing the ability to observe and distinguish a multiplex of objects simultaneously, even if in motion, with minimal or no mechanical tracking required. Spectra may be viewed directly with the unaided eye, or photographed with common consumer cameras.
Claims19
A spectrograph comprising:
- a housing having a front, a back, a top, a bottom, a first side, a second side and a generally hollow interior;
- an entrance lens group having a focal length resulting in a focal point, wherein a focal ratio of the entrance lens group is less than f/4, wherein the entrance lens group is located at the front of the housing, wherein the entrance lens group has a diameter of at least 3 mm;
- wherein the housing lacks any aperture located between the entrance lens and an object providing a light to be observed, and wherein the entrance lens group acts as the only entrance for the light received from the object;
- a grating located within the interior of the housing;
- and
- a viewing port located at the back or sides of the housing wherein no apertures are located between the entrance lens group and the viewing port, and wherein the viewing port is located after the grating along a path of light to be observed, wherein a distance the path of light travels between the entrance lens group and the viewing port is at least 10× or greater the distance between the entrance lens and the focal point wherein the focal point is located on an object field.
3 more elements
A method of using a spectrograph comprising the steps of:
- providing a spectrograph having an interior and having an entrance lens having a focal ratio less than f/4;
- and
- passing light through the entrance lens wherein the light travels an initial path to an echelle grating wherein the light is directed back from the echelle grating toward the entrance lens within approximately 30 degrees of the initial path to a cross-dispersive grating, wherein the cross-dispersive grating directs the light at an angle approximately orthogonal to the initial path to a viewing port, wherein a distance the light travels from the entrance lens to the viewing port is at least 10× greater than a distance between the entrance lens and a focal point of the entrance lens, and wherein the focal point is located on an object field of the entrance lens.
Dependencies are inferred from the claim text.