US3867034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser angular rate sensor biasing apparatus
Assignee: Honeywell Inc
•
Filing: 1973-11-16
•
Granted: 1975-02-18
•
Expires: 1993-11-16
Abstract
Abstract Electro-optical apparatus for preventing lock-in in a laser angular rate sensor. A Faraday material is placed between two wave plates, the birefringence of each wave plate varying in response to applied electric fields. The two wave plates may be positioned so that the principal axes of their index ellipses are substantially orthogonal to one another. A cyclic voltage of high frequency is applied to each wave plate to rapidly and cyclically vary its birefringence. This achieves biasing apparatus having a longer effective optical path length first in one direction and then in the opposite direction.
Inventors
- 👤 Frederick Aronowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:28
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/081; H01S3/083; G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66; G01C19/68
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
175 words
Apparatus for use in the optical ring path of a ring laser to prevent mode locking, which comprises: a. a Faraday material adapted to be placed in said optical ring path; b. a first wave plate exhibiting electric field dependent birefringence and being characterized by a first index ellipse, said first wave plate in the optical ring path adjacent said Faraday material; c. a second wave plate exhibiting electric field dependent birefringence, being constructed of the same material as said first wave plate and being characterized by a second index ellipse, said second wave plate placed in the optical ring path adjacent said Faraday material at the opposite end from said first wave plate, with the second indeX ellipse oriented so that its principal axes are not parallel with the correspondent principal axes of the first index ellipse; and d. means for applying an electric field which varies cyclically in magnitude and polarity to said first and second wave plates, to achieve cyclic variations in the optical path length around the laser in each direction.
Claim 2
Dependent Claim
175 words
Apparatus for use in the optical ring path of a ring laser to prevent mode locking, which comprises: a. a Faraday material adapted to be placed in said optical ring path; b. a first wave plate exhibiting electric field dependent birefringence and being characterized by a first index ellipse, said first wave plate in the optical ring path adjacent said Faraday material; c. a second wave plate exhibiting electric field dependent birefringence, being constructed of the same material as said first wave plate and being characterized by a second index ellipse, said second wave plate placed in the optical ring path adjacent said Faraday material at the opposite end from said first wave plate, with the second indeX ellipse oriented so that its principal axes are not parallel with the correspondent principal axes of the first index ellipse; and d. means for applying an electric field which varies cyclically in magnitude and polarity to said first and second wave plates, to achieve cyclic variations in the optical path length around the laser in each direction.
Claim 3
Dependent Claim
32 words
The apparatus of claim 1 wherein the means for applying an electric field to said wave plates generates a voltage which varies cyclically at a frequency of the order of 104 Hertz.
Claim 4
Dependent Claim
33 words
The apparatus of claim 1 wherein the first and second wave plates are oriented so that the correspondent principal axes of the first and second index ellipses are substantially perpendicular to one another.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |