Control system for ruling blazed, aberration corrected diffraction gratings
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorDouglas B. Leviton
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Abstract
The grooved surface of an aberration-corrected holographic model grating is sensed by utilizing the sensing head of a scanning tunneling microscope. The sensing head is mechanically connected to a blazing type stylus for replicating the groove pattern of the holographic model on a ruled grating blank. A ruling engine causes the sensing head not only to scan the surface of the holographic grating model but also drive a blazing type ruling stylus or an equivalent type device in accordance with an error signal resulting from a departure of a sensing tip from the top of the holographic model groove as a function of tunneling current.
Claims20
A method of ruling a diffraction grating, comprising the steps of:
- locating means for forming diffraction grating grooves on a diffraction grating blank adjacent the surface of said blank;
- scanning the surface of a holographic model diffraction grating;
- sensing the grooved surface of the holographic model diffraction grating,
- generating electrical signals representative of the spatial characteristics of the grooved surface during the sensing step;
- controlling said means for forming grooves in response to said electrical signals;
- and
- replicating the grooves of the model grating in the surface of the diffraction grating blank.
Apparatus for ruling a diffraction grating, comprising:
- a model diffraction grating including a pattern of holographic grating grooves on a surface thereof;
- a diffraction grating blank having a surface which is to be ruled with diffraction grating grooves;
- means for sensing the grooved surface of the holographic model diffraction grating and generating electrical signals representative of the spatial characteristics of the grooved surface thereof;
- means for replicating the grooves of the model grating in the surface of the diffraction grating blank in response to said electrical signals;
- and
- means for scanning the sensing means in a predetermined pattern over the surface of the model diffraction together with said means for replicating.
Dependencies are inferred from the claim text.