US5388173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for forming aperiodic gratings in optical fibers
Assignee: RTX Corp
•
Filing: 1993-12-20
•
Granted: 1995-02-07
•
Expires: 2013-12-20
Abstract
Abstract A method and apparatus for simultaneously exposing an optical fiber 32, made of a material which has a refractive index that can be permanently changed by exposure to light of a predetermined intensity at a predetermined wavelength, to two writing light beams 268,272 which intersect and interfere in a predetermined region 30 of the fiber 32 so as to create an interference pattern along a longitudinal axis of the fiber 32, for a time long enough to form a permanent refractive index variation in the waveguide. Each of said two writing beams have a predetermined number of wavelengths, each wavelength being sufficiently different from each other so as to cause said refractive index variation to be an aperiodic variation. Also, each wavelength represents a Fourier component of the desired aperiodic refractive index variation.
Inventors
- 👤 William H. Glenn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:12
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/02057; G02B6/02076; G02B6/02123; G02B6/02133; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
124 words
A method of impressing an aperiodic grating, comprising the steps of: obtaining an optical waveguide made of a material which has a refractive index that can be permanently changed by exposure to light of a predetermined intensity at a predetermined wavelength; and simultaneously exposing the waveguide to two writing light beams which intersect and interfere in a predetermined region of the waveguide so as to create an interference pattern along a longitudinal axis of the waveguide for a time long enough to form a permanent refractive index variation in the waveguide, each of said two writing beams having a predetermined number of wavelengths, each wavelength being sufficiently different from each other so as to cause said refractive index variation to be an aperiodic variation.
Claim 2
Independent Claim
124 words
A method of impressing an aperiodic grating, comprising the steps of: obtaining an optical waveguide made of a material which has a refractive index that can be permanently changed by exposure to light of a predetermined intensity at a predetermined wavelength; and simultaneously exposing the waveguide to two writing light beams which intersect and interfere in a predetermined region of the waveguide so as to create an interference pattern along a longitudinal axis of the waveguide for a time long enough to form a permanent refractive index variation in the waveguide, each of said two writing beams having a predetermined number of wavelengths, each wavelength being sufficiently different from each other so as to cause said refractive index variation to be an aperiodic variation.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein each of said wavelengths in said step of exposing comprises a Fourier component of said aperiodic refractive index variation.
Claim 4
Dependent Claim
20 words
The method of claim 1 further comprising a step of modulating the amplitude of a predetermined number of said wavelengths.
Claim 5
Dependent Claim
16 words
The method of claim 1 wherein said aperiodic refractive index variation exhibits a broadband reflectivity profile.
Claim 6
Independent Claim
129 words
An apparatus for impressing an aperiodic grating into a region of an optical waveguide, comprising= light source means, for providing a predetermined number of source beams, each beam having a predetermined wavelength; wavelength combining means, for combining said source beams into a single beam; beamsplitting means for splitting said single beam into at least two writing beams; and beam directing means for directing said writing beams so as to intersect on a region of the waveguide, thereby creating an interference pattern along a longitudinal axis of the waveguide for a time long enough to form a permanent refractive index variation in the waveguide, the wavelengths associated with said source beams being sufficiently different from each other so as to cause said refractive index variation to be an aperiodic variation.
Claim 7
Independent Claim
129 words
An apparatus for impressing an aperiodic grating into a region of an optical waveguide, comprising= light source means, for providing a predetermined number of source beams, each beam having a predetermined wavelength; wavelength combining means, for combining said source beams into a single beam; beamsplitting means for splitting said single beam into at least two writing beams; and beam directing means for directing said writing beams so as to intersect on a region of the waveguide, thereby creating an interference pattern along a longitudinal axis of the waveguide for a time long enough to form a permanent refractive index variation in the waveguide, the wavelengths associated with said source beams being sufficiently different from each other so as to cause said refractive index variation to be an aperiodic variation.
Claim 8
Dependent Claim
42 words
The apparatus of claim 5, wherein said light source means comprises: broadband light source means for providing a broadband source light having a plurality of wavelengths; and wavelength separation means, for separating said broadband light into said predetermined number of source beams.
Claim 9
Dependent Claim
21 words
The apparatus of claim 5, further comprising amplitude modulation means, for independently modulating the amplitude of each of said source beams.
Claim 10
Dependent Claim
33 words
The apparatus of claim 7, further comprising signal processing means for providing an amplitude modulation signal to said amplitude modulation means and for determining the desired amplitude of each of said source beams.
Claim 11
Dependent Claim
14 words
The apparatus of claim 5, wherein said aperiodic variation exhibits a broadband reflectivity profile.
Claim 12
Independent Claim
130 words
An apparatus for impressing an aperiodic grating into a region of an optical waveguide, comprising: variable wavelength light source means, for providing a variable wavelength source light; beamsplitting means for splitting said source light into at least two writing beams; beam directing means for directing said writing beams so as to intersect on a region of the optical waveguide, thereby creating an interference pattern along a longitudinal axis of the waveguide, for a time long enough to form a permanent refractive index variation in the waveguide; and signal processing means for providing a wavelength control signal to said variable wavelength light source means, for setting different successive wavelengths, each wavelength forming a different refractive index variation, so as to create a total refractive index variation which is an aperiodic variation.
Claim 13
Independent Claim
130 words
An apparatus for impressing an aperiodic grating into a region of an optical waveguide, comprising: variable wavelength light source means, for providing a variable wavelength source light; beamsplitting means for splitting said source light into at least two writing beams; beam directing means for directing said writing beams so as to intersect on a region of the optical waveguide, thereby creating an interference pattern along a longitudinal axis of the waveguide, for a time long enough to form a permanent refractive index variation in the waveguide; and signal processing means for providing a wavelength control signal to said variable wavelength light source means, for setting different successive wavelengths, each wavelength forming a different refractive index variation, so as to create a total refractive index variation which is an aperiodic variation.
Claim 14
Dependent Claim
19 words
The apparatus of claim 10, further comprising amplitude modulation means, for independently modulating the amplitude of said source light.
Claim 15
Dependent Claim
31 words
The apparatus of claim 11, further comprising signal processing means for providing an amplitude modulation signal to said amplitude modulation means and for determining the desired amplitude of said source light.
Claim 16
Dependent Claim
23 words
The apparatus of claim 10, further comprising phase modulation means, for independently modulating the phase of at least one of said writing beams.
Claim 17
Dependent Claim
31 words
The apparatus of claim 13, further comprising signal processing means for providing a phase modulation signal to said phase modulation means and for determining the phase relationship between said writing beams.
Claim 18
Dependent Claim
14 words
The apparatus of claim 10, wherein said aperiodic variation exhibits a broadband reflectivity profile.
Claim 19
Independent Claim
141 words
An apparatus for impressing an aperiodic grating into a region of an optical waveguide, comprising: light source means, for providing a source light having a predetermined wavelength; beamsplitting means for splitting said source light into at least two writing beams; variable beam directing means for directing said writing beams so as to intersect on a region of the optical waveguide at a predetermined angle of incidence thereon, thereby creating an interference pattern along a longitudinal axis of the waveguide, for a time long enough to form a permanent refractive index variation in the waveguide; and signal processing means for providing a wavelength control signal to said variable beam directing means, for setting different successive angles of incidence, each angle causing a different refractive index variation to form, so as to create a total refractive index variation which is an aperiodic variation.
Claim 20
Independent Claim
141 words
An apparatus for impressing an aperiodic grating into a region of an optical waveguide, comprising: light source means, for providing a source light having a predetermined wavelength; beamsplitting means for splitting said source light into at least two writing beams; variable beam directing means for directing said writing beams so as to intersect on a region of the optical waveguide at a predetermined angle of incidence thereon, thereby creating an interference pattern along a longitudinal axis of the waveguide, for a time long enough to form a permanent refractive index variation in the waveguide; and signal processing means for providing a wavelength control signal to said variable beam directing means, for setting different successive angles of incidence, each angle causing a different refractive index variation to form, so as to create a total refractive index variation which is an aperiodic variation.
Claim 21
Dependent Claim
19 words
The apparatus of claim 16, further comprising amplitude modulation means, for independently modulating the amplitude of said source light.
Claim 22
Dependent Claim
31 words
The apparatus of claim 17, further comprising signal processing means for providing an amplitude modulation signal to said amplitude modulation means and for determining the desired amplitude of said source light.
Claim 23
Dependent Claim
23 words
The apparatus of claim 16, further comprising phase modulation means, for independently modulating the phase of at least one of said writing beams.
Claim 24
Dependent Claim
31 words
The apparatus of claim 19, further comprising signal processing means for providing a phase modulation signal to said phase modulation means and for determining the phase relationship between said writing beams.
Claim 25
Dependent Claim
14 words
The apparatus of claim 16, wherein said aperiodic variation exhibits a broadband reflectivity profile.
References Cited (Backward Citations)
US3995937A
Cited
US4725110A
Cited
US4807950A
Cited
USH474H
Cited
US4749248A
Cited
US5006716A
Cited
US5007705A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-06 | 1998-08-08 | 1999-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-06 | 2002-08-08 | 2003-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-06 | 2006-08-08 | 2007-02-07 | $7700.00 | Window Closed / Lapsed |