US3576502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transverse mode switching and image amplification in optical masers
Assignee: AT&T Inc
•
Filing: 1968-05-13
•
Granted: 1971-04-27
•
Expires: 1988-05-13
Abstract
Abstract Transverse mode switching is accomplished in a laser oscillating in at least one transverse mode by the injection therein of a low level seeding signal of the desired output mode. If the laser is designed to enhance transverse mode competition (i.e., the cavity geometry approaches either a concentric or plane parallel configuration), then a seeding signal of the correct frequency will cause the laser to switch (i.e., spatially lock) to oscillation entirely in the injected mode. In addition, if the cavity resonator is frequency degenerate at the frequency of a complex (i.e., many transverse modes) input signal, and if the resonator is designed to provide approximately equal gain for all of these transverse modes, then the laser will lock onto the transverse modes of the input signal and image-amplify the signal.
Inventors
- 👤 Wilbur D Jhonston Jr
- 👤 Tingye Li
- 👤 Peter W Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:28
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/10084; H01S3/10092; H01S3/005; H01S3/0064; H01S3/05; H01S3/08; H01S3/08018; H01S3/0804; H01S3/08045; H01S3/0805
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
42 words
The optical apparatus of claim 1 wherein said cavity resonator is designed such that all of the transverse mode resonant frequencies are near to each other compared to the homogeneous linewidth of a mode, and such that the transverse modes spatially overlap.
Claim 2
Dependent Claim
23 words
The optical apparatus of claim 1 wherein said cavity resonator is degenerate, all of the transverse mode resonances being at the same frequency.
Claim 3
Dependent Claim
43 words
The optical apparatus of claim 1 wherein said cavity resonator is half-degenerate, one-half of the transverse mode resonances being at one frequency and the other half at another frequency, the two frequencies being symmetrically spaced about the peak of the laser gain curve.
Claim 4
Dependent Claim
95 words
The optical apparatus of claim 1 for use as a binary optical switch comprising: means for causing said laser oscillator to oscillate in a single transverse mode, and wherein said injecting means comprises means for injecting into said cavity resonator an optical signal characterized by another single transverse mode, and maximum transverse mode competition is provided in said cavity resonator designed to maximize the spatial overlap of the transverse modes and to cause all of the transverse mode resonant frequencies to be near to each other as compared to the natural linewidth of a mode.
Claim 5
Dependent Claim
23 words
The optical apparatus of claim 5 wherein said cavity resonator comprises a pair of spherical reflectors concentrically disposed with respect to one another.
Claim 6
Dependent Claim
21 words
The optical apparatus of claim 5 wherein said cavity resonator comprises a pair of planar reflectors disposed parallel to one another.
Claim 7
Dependent Claim
149 words
The optical apparatus of claim 1 for use as an image amplifier wherein said cavity resonator is designed to have at least as many transverse modes as the injected optical signal, to reduce transverse mode competition in said laser oscillator by reducing the spatial overlap of the transverse modes, to provide for approximately equal net gain of each of the transverse modes, and to be frequency degenerate at the frequency of the injected optical signal. 9, The optical apparatus of claim 8 wherein said cavity resonator comprises a pair of spaced reflectors said optical signal being injected into said cavity resonator through one of said reflectors , said one reflector having high transmissivity thereby to provide equal gain for each of the transverse modes by making transmission loss the dominant part of the total loss in said laser oscillator as compared to the diffraction losses of the transverse modes.
Claim 8
Dependent Claim
19 words
The optical apparatus of claim 8 wherein said cavity resonator configuration is nearly concentric and between concentric and confocal.
Claim 9
Dependent Claim
21 words
the optical apparatus of claim 8 wherein said cavity resonator configuration is nearly plane parallel and between confocal and plane parallel.
Claim 10
Dependent Claim
45 words
The optical apparatus of claim 8 wherein said cavity resonator configuration is concentric and the active medium of said laser oscillator is confined to a small volume at the center of said cavity resonator so as to reduce the spatial overlap of the transverse modes.
Claim 11
Dependent Claim
62 words
The optical apparatus of claim 8 wherein said cavity resonator comprises a pair of spaced spherical reflectors of radii R1 and R2, respectively, a convex lens disposed coaxially between said spaced reflectors a distance L1 from the reflector of radius R1, and spaced a distance L2 from the reflector of radius R2, and wherein the focal length of said lens is approximately
Claim 12
Dependent Claim
56 words
The optical apparatus of claim 1 for use as a high brightness device wherein said cavity resonator is designed to maximize transverse mode competition, such competition favoring oscillation in the fundamental transverse mode, and wherein said injeCting means comprises means for injecting into said cavity resonator an optical signal characterized by only the fundamental transverse mode.
Claim 13
Dependent Claim
24 words
The optical apparatus of claim 14 wherein said cavity resonator comprises a pair of spaced spherical reflectors disposed concentrically with respect to one another.
Claim 14
Dependent Claim
22 words
The optical apparatus of claim 14 wherein said cavity resonator comprises a pair of spaced parallel reflectors disposed parallel to one another.
References Cited (Backward Citations)
US3452286A
Cited
US3426286A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |