US3875422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Four photon parametric amplification in glassy optical waveguides
Assignee: AT&T Inc
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Filing: 1974-07-24
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Granted: 1975-04-01
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Expires: 1994-07-24
Abstract
Abstract An optical parametric amplifier is provided in a glassy material in optical waveguiding fiber form. The fiber is moderately multimoded with respect to the intended pump and signal wavelengths, typically such that lambda 2 0.05 to 0.1 times the core diameter and lambda p is marginally less than lambda s. The pump beam is injected into the fiber in two modes simultaneously by focusing it on the fiber with a spot size substantially smaller than the core diameter, illustratively less than one-half the core diameter. Coherence lengths for exponential parametric gain longer than 10 meters and gains more than double the usual Reman gain have been obtained this way.
Inventors
- 👤 Rogers Hall Stolen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:41
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/39; G02F1/395
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
An active optical device comprising a glassy optical waveguiding fiber dimensioned to be moderately multi-moded with respect to the intended signal wavelength and the intended pump wavelength, means for launching into said fiber a beam of said signal wavelength in a selected mode, and means for launching into said fiber a beam of said pump wavelength in two modes simultaneously to generate an idler wavelength differing from said pump wavelength in the opposite sense from said signal wavelength. 9. an active optical device comprising a glassy optical waveguiding fiber dimensioned to be moderately multi-moded with respect to the intended pump wavelength, and means for injecting into said fiber a beam of said pump wavelength in two modes simultaneously to generate signal and idler wavelengths differing from said pump wavelength in opposite senses and differing in modes.
Claim 2
Dependent Claim
136 words
An active optical device comprising a glassy optical waveguiding fiber dimensioned to be moderately multi-moded with respect to the intended signal wavelength and the intended pump wavelength, means for launching into said fiber a beam of said signal wavelength in a selected mode, and means for launching into said fiber a beam of said pump wavelength in two modes simultaneously to generate an idler wavelength differing from said pump wavelength in the opposite sense from said signal wavelength. 9. an active optical device comprising a glassy optical waveguiding fiber dimensioned to be moderately multi-moded with respect to the intended pump wavelength, and means for injecting into said fiber a beam of said pump wavelength in two modes simultaneously to generate signal and idler wavelengths differing from said pump wavelength in opposite senses and differing in modes.
Claim 3
Dependent Claim
45 words
An active optical device according to claim 1 in which the signal beam launching means and the pump beam launching means are mutually adapted to launch combinations of a signal mode and two pump modes yielding relative insensitivity to fiber imperfections including fiber diametral variations.
Claim 4
Dependent Claim
26 words
An active optical device according to claim 1 including means for yielding the lowest frequency beam in a mode of order higher than lowest order mode.
Claim 5
Dependent Claim
43 words
An active optical device according to claim 3 in which the signal wavelength is selected to have the lowest frequency, and the signal launching means comprises means for launching the signal beam in a mode of order higher than the lowest order mode.
Claim 6
Dependent Claim
93 words
An optical amplifier comprising a glassy optical waveguiding fiber dimensioned to be moderately multi-moded with respect to the intended signal wavelength and the intended pump wavelength, means for launching into said fiber a signal beam of frequency lower than the pump frequency and in a mode of order higher than the lowest and means for launching into said fiber a beam of said pump wavelength in two modes simultaneously to obtain substantial amplification of said signal beam together with generation of an idler wave of frequency higher than said signal and pump frequencies.
Claim 7
Dependent Claim
93 words
An optical amplifier comprising a glassy optical waveguiding fiber dimensioned to be moderately multi-moded with respect to the intended signal wavelength and the intended pump wavelength, means for launching into said fiber a signal beam of frequency lower than the pump frequency and in a mode of order higher than the lowest and means for launching into said fiber a beam of said pump wavelength in two modes simultaneously to obtain substantial amplification of said signal beam together with generation of an idler wave of frequency higher than said signal and pump frequencies.
Claim 8
Dependent Claim
40 words
An optical amplifier according to claim 5 including means for separating the signal and idler beams propagating from the fiber, whereby the idler beam bears the same information as the signal beam in frequency-shifted form and can be separately detected.
Claim 9
Dependent Claim
54 words
An optical amplifier according to claim 5 in which the signal beam launching means and pump beam launching means are mutually adapted for launching the signal beam in the same mode as the higher order pump mode, whereby the idler beam is inherently generated in the same mode as the lower order pump mode.
Claim 10
Dependent Claim
57 words
An optical amplifier according to claim 7 in which the pump and signal beam injecting means include in common means for focusing both of said beams in axial alignment onto the end of the fiber with spot diameters no greater than half the fiber core diameter, whereby the higher order pump mode and signal mode are LP02.
References Cited (Backward Citations)
US3297875A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |