Curved volume phase holographic (VPH) diffraction grating with tilted fringes and spectrographs using same
AssigneeThe University of North Carolina at Chapel Hill
InventorsJ. Christopher Clemens, Darragh Evelyn Anthony Adam O'Donoghue
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Abstract
The subject matter described herein includes a curved VPH grating with tilted fringes and spectrographs, both retroreflective and transmissive, that use such gratings. A VPH grating according to the subject matter described herein includes a first curved surface for receiving light to be diffracted. The grating includes an interior region having tilted fringes to diffract light that passes through the first surface. The grating further includes a second curved surface bounding the interior region on a side opposite the first surface and for passing light diffracted by the fringes.
Claims11
A spectrograph comprising:
- a first curved volume phase holographic (VPH) transmission diffraction grating comprising a first curved surface through which light to be diffracted enters the grating, a second curved second curved surface through which diffracted light exits the grating, and an interior region located between the first and second curved surfaces:
- the interior region having tilted fringes holographically recorded within the interior region for diffracting at least some light that passes through the first surface and the interior region, wherein the tilted fringes have tilt angles θ recorded to be different from each other and substantially constant with respect to light rays incident on the first surface that impinge on the fringes;
- the second curved surface for passing the light diffracted by the fringes from the interior region through the second surface to a region exterior to the first curved VPH transmission diffraction grating on the side opposite the first curved surface;
- and
- optics for directing the light to and from the first curved VPH transmission diffraction grating.
Dependencies are inferred from the claim text.