US5058281A
Expired / Lapsed
US
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Control system for ruling blazed, aberration corrected diffraction gratings
Assignee: National Aeronautics and Space Administration
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Filing: 1990-08-23
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Granted: 1991-10-22
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Expires: 2010-08-23
Abstract
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.
Inventors
- 👤 Douglas B. Leviton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:45
CPC Classifications
B; B82; B82Y; B82Y15/00; B23; B23Q; B23Q35/00; B23Q35/04; B23Q35/08; B23Q35/12; B23Q35/127; B23Q35/129; B24; B24B; B24B13/00; B24B13/04; B24B13/046; G; G02; G02B; G02B27/00; G02B27/0025; G02B27/0031; G02B5/00; G02B5/18; G02B5/1847; G02B5/1852; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/852; Y10S977/855
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
92 words
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.
Claim 2
Independent Claim
92 words
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.
Claim 3
Dependent Claim
38 words
The method as defined by claim 1 wherein said step of sensing comprises the step of sensing the spatial characteristics of the grooves of the holographic model diffraction grating with a sensing head of a scanning tunneling microscope.
Claim 4
Dependent Claim
43 words
The method as defined by claim 2 wherein said step of sensing includes applying a bias voltage between the model grating and the sensing head and sensing quantum mechanical tunneling current to obtain a surface profile of individual grooves of the model grating.
Claim 5
Dependent Claim
23 words
The method as defined by claim 3 wherein said sensing step comprises sensing the grooved surface of an aberration corrected holographic grating model.
Claim 6
Dependent Claim
27 words
The method as defined by claim 3 and additionally including the step of securing the model diffraction grating and the diffraction grating blank on a common carriage.
Claim 7
Dependent Claim
24 words
The method as defined by claim 5 and additionally including the step of physically linking said sensing head and said means for forming grooves.
Claim 8
Dependent Claim
24 words
The method as defined by claim 6 wherein said step of scanning comprises scanning the surface of the model grating with a ruling engine.
Claim 9
Dependent Claim
50 words
The method as defined by claim 7 wherein said step of scanning with a ruling engine comprises driving said carriage along two of three mutually perpendicular axes and wherein said step of sensing quantum mechanical tunneling current comprises sensing said current along a third of said three mutually perpendicular axes.
Claim 10
Dependent Claim
21 words
The method as defined by claim 8 wherein said replicating step comprises blazing grooves in the surface of the grating blank.
Claim 11
Dependent Claim
24 words
The method as defined by claim 8 wherein said replicating step comprises ruling the surface of the grating blank with a blazing type stylus.
Claim 12
Dependent Claim
111 words
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.
Claim 13
Dependent Claim
111 words
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.
Claim 14
Dependent Claim
29 words
The apparatus as defined by claim 11 wherein means for sensing the groove surface of the holographic model diffraction grating comprises a sensing head of a scanning tunneling microscope.
Claim 15
Dependent Claim
45 words
The apparatus as defined by claim 12 and further comprising means for applying a bias voltage between the model grating and the sensing head, to generate quantum mechanical tunneling current which is sensed to obtain a surface profile of individual grooves of the model grating.
Claim 16
Dependent Claim
18 words
The apparatus as defined by claim 13 wherein said holographic model comprises an aberration corrected holographic grating model.
Claim 17
Dependent Claim
21 words
The apparatus as defined by claim 14 and further comprising a carriage supporting both the model grating and the grating blank.
Claim 18
Dependent Claim
26 words
The apparatus as defined by claim 15 and wherein said means for moving includes a pantographic arm connecting the sensing head with the means for replicating.
Claim 19
Dependent Claim
35 words
The apparatus as defined by claim 16 wherein said means for moving additionally includes a ruling engine which operates to respectively move said carriage and said pantographic arm along two of three mutually perpendicular axes.
Claim 20
Dependent Claim
33 words
The apparatus as defined by claim 17 and additionally including means for moving the sensing means along a third of said three mutual axes in response to the sensed quantum mechanical tunneling current.
Claim 21
Dependent Claim
54 words
The apparatus as defined by claim 18 wherein said means for moving the sensing means along said third axis includes a control loop which operates to maintain a tip of the sensing head at a constant height above a predetermined groove of the model grating in response to the sensed quantum mechanical tunneling current.
Claim 22
Dependent Claim
82 words
The apparatus as defined by claim 19 wherein said control loop includes a signal processor responsive to the sensed quantum mechanical tunneling current and generating control signals for controlling the movement of the tip of the sensing head along said third axis and additionally the movement of the carriage via the ruling engine along one of said two axes, and wherein the ruling engine controls movement of the pantographic arm and the means for replicating along the other of said two axes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-21 | 1995-04-22 | 1995-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-21 | 1999-04-22 | 1999-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-21 | 2003-04-22 | 2003-10-22 | $7700.00 | Window Closed / Lapsed |