US4850041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser radar with adjustable local oscillator
Assignee: Lockheed Martin Tactical Systems Inc
•
Filing: 1987-05-13
•
Granted: 1989-07-18
•
Expires: 2007-05-13
Abstract
Abstract The relative intensity of the transmit beam and the local oscillator beam in a ladar diplexer can be continuously adjusted during operation by using a rotatable retardation plate with a slightly inclined "C" axis to turn a polarized laser beam into a composite beam having two components polarized in mutually perpendicular directions. The relative intensity of the components is adjustable by varying the inclination of the "C" axis. The composite beam is applied to the same polarizer element normally used to separate the return signal from the transmit beam. The polarizer acts as the beam splitter which separates the local oscillator beam from the transmit beam. The described configuration also saves one beam splitter and allows improved packaging and alignment of the diplexer.
Inventors
- 👤 Dudley A. Roberts
- 👤 John S. Chudy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:39
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/48; G01S7/481; G01S7/4811; G01S7/4812; G01S7/499
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
160 words
A laser diplexer, comprising: (a) a laser for producing a laser beam polarized in a first direction: (b) a retardation plate interposed in the path of said laser beam, said plate being so oriented as to produce a beam having a transmit beam component polarized in said first direction and a local oscillator beam component polarized in a second direction perpendicular to said first direction: (c) a detector; and (d) a polarizer element interposed in the path of said transmit beam and said local oscillator beam so as to reflect said transmit beam toward a target, but refract said local oscillator beam toward said detector; (e) said polarizer element being also interposed in the path of the return signal from said target so as to refract the return signal beam polarized in said second direction, and (f) said diplexer further comprising optical means for orienting said return signal beam parallel and adjacent to said local oscillator beam toward said detector.
Claim 2
Dependent Claim
160 words
A laser diplexer, comprising: (a) a laser for producing a laser beam polarized in a first direction: (b) a retardation plate interposed in the path of said laser beam, said plate being so oriented as to produce a beam having a transmit beam component polarized in said first direction and a local oscillator beam component polarized in a second direction perpendicular to said first direction: (c) a detector; and (d) a polarizer element interposed in the path of said transmit beam and said local oscillator beam so as to reflect said transmit beam toward a target, but refract said local oscillator beam toward said detector; (e) said polarizer element being also interposed in the path of the return signal from said target so as to refract the return signal beam polarized in said second direction, and (f) said diplexer further comprising optical means for orienting said return signal beam parallel and adjacent to said local oscillator beam toward said detector.
Claim 3
Dependent Claim
27 words
The diplexer of claim 1, in which said optical means include a pair of mirrors, each of said mirrors being pivotally movable about two mutually orthogonal axes.
Claim 4
Dependent Claim
34 words
The diplexer of claim 2, in which said laser, retardation plate, polarizer element, and detector form a generally elongated optical system, and said mirrors are disposed laterally of said system on one side thereof.
Claim 5
Dependent Claim
15 words
The diplexer of claim 1, in which said optical means include a mixing beam splitter.
Claim 6
Dependent Claim
53 words
The diplexer of claim 1, in which said retardation plate is mounted for rotational movement about said laser beam so as to allow adjustment of the relative intensity of said transmit beam and local oscillator beam components by rotating said retardation plate about an axis parallel to the direction of said laser beam.
Claim 7
Dependent Claim
26 words
The diplexer of claim 1, in which the relative intensity of said transmit beam and local oscillator beam is continuously adjustable during operation of said diplexer.
References Cited (Backward Citations)
US3215840A
Cited
US3409369A
Cited
US3435229A
Cited
US3503682A
Cited
US3532890A
Cited
US3584221A
Cited
US3638024A
Cited
US3676003A
Cited
US3694656A
Cited
US3975628A
Cited
US4184767A
Cited
US4209253A
Cited
US4011445A
Cited
US4063084A
Cited
US4131792A
Cited
US4413905A
Cited
US4299484A
Cited
US4270862A
Cited
US4439014A
Cited
US4506388A
Cited
US4530600A
Cited
US4596052A
Cited
US4643575A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |