Patent US5422745A successfully refreshed from Google Patents.
US5422745A
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Preparation of permanent photowritten optical diffraction gratings in irradiated glasses
Assignee: United States Department of the Navy
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Filing: 1992-10-30
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Granted: 1995-06-06
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Expires: 2012-10-30
Abstract
Abstract A fast process for photowriting a permanent, high efficiency optical grating comprises darkening glass by irradiation and photobleaching the darkened glass by exposing the glass to interfering writing laser beams, thereby forming the grating.
Inventors
- 👤 Glen M. Williams
- 👤 David A. Dutt
- 👤 Jacqueline A. Ruller
- 👤 Edward J. Friebele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:33
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/02057; G02B6/02076; G02B6/02123; G02B6/02133; G02B5/00; G02B5/18; G02B5/1847; G02B5/1857; G02B6/02114
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
63 words
A process for photowriting a diffraction grating into a glass, comprising: a) exposing the glass to a quantity of electromagnetic radiation to darken said glass, wherein said electromagnetic radiation has energy of at least about hν=5 eV, and b) exposing said irradiated glass to interfering light beams of essentially equal wavelength and intensity, to selectively bleach said darkened glass, thereby forming the grating.
Claim 2
Dependent Claim
63 words
A process for photowriting a diffraction grating into a glass, comprising: a) exposing the glass to a quantity of electromagnetic radiation to darken said glass, wherein said electromagnetic radiation has energy of at least about hν=5 eV, and b) exposing said irradiated glass to interfering light beams of essentially equal wavelength and intensity, to selectively bleach said darkened glass, thereby forming the grating.
Claim 3
Dependent Claim
12 words
The process of claim 1, wherein the glass is a silicate glass.
Claim 4
Dependent Claim
30 words
The process of claim 2, wherein the silicate glass is doped with at most about 15 mol % of a rare earth element or compound of said rare earth element.
Claim 5
Dependent Claim
12 words
The process of claim 3, wherein said rare earth element is praseodymium.
Claim 6
Dependent Claim
17 words
The process of claim 1, wherein said electromagnetic radiation has energy of at least about hν=50 keV.
Claim 7
Dependent Claim
20 words
The process of claim 1, wherein said quantity of electromagnetic radiation is between about 0.5 Mrad and about 2.0 Mrad.
Claim 8
Dependent Claim
15 words
The process of claim 1, wherein said quantity of electromagnetic radiation is about 1.0 Mrad.
Claim 9
Dependent Claim
16 words
The process of claim 1, wherein said quantity of electromagnetic radiation darkens the glass to saturation.
Claim 10
Dependent Claim
12 words
The process of claim 1, wherein the glass is a optical fiber.
Claim 11
Dependent Claim
19 words
The process of claim 1, wherein said grating has a peak-to-valley Δn of at least about 0.5×10 -5 .
Claim 12
Dependent Claim
19 words
The process of claim 1, wherein said grating has a peak-to-valley Δn of at least about 1.0×10 -5 .
Claim 13
Dependent Claim
24 words
The process of claim 1, wherein said interfering light beams saturate said darkened glass, thereby forming said grating, in at most about 120 seconds.
Claim 14
Dependent Claim
24 words
The process of claim 1, wherein said interfering light beams saturate said darkened glass, thereby forming said grating, in at most about 60 seconds.
Claim 15
Dependent Claim
18 words
The process of claim 1, wherein said interfering light beams have wavelengths of at most about 514 nm.
Claim 16
Dependent Claim
21 words
The process of claim 1, wherein said interfering light beams have wavelengths of between about 490 nm and about 400 nm.
Claim 17
Dependent Claim
16 words
The process of claim 1, wherein said interfering light beams have wavelengths of about 488 nm.
Claim 18
Dependent Claim
25 words
The process of claim 1, wherein said interfering light beams have output powers of between about 5 W/cm 2 and about 75 W/cm 2 .
Claim 19
Dependent Claim
19 words
The process of claim 1, wherein said interfering light beams have output powers of about 50 W/cm 2 .
References Cited (Backward Citations)
US4390637A
Cited
US4728165A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-06-05 | 1998-12-05 | 1999-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-05 | 2002-12-05 | 2003-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-05 | 2006-12-05 | 2007-06-06 | $7700.00 | Window Closed / Lapsed |