US4746878A
Expired / Lapsed
US
⏱️ 0.0 years remaining
C. W. laser wavemeter/frequency locking technique
Assignee: Agilent Technologies Inc
•
Filing: 1986-07-08
•
Granted: 1988-05-24
•
Expires: 2006-07-08
Abstract
Abstract A wavemeter/frequency locking technique suitable for indirectly locking an optical frequency f 0 to a radio frequency f 1 or for locking the radio frequency to the optical frequency. A beam of optical frequency f 0 is phase modulated by a signal of average frequency f 1 that is itself modulated at frequency f 2 . The modulated beam is passed through a filter to a detector to produce a detector output signal that has components at linear integral sums of f 1 and f 2 . A pair of control signals are generated that are proportional to the amplitude of two of the components of the detector output signal. These control signals are separately used in a pair of servo loops to separately establish fixed values of f 0 /f f and f 1 /f f , where f f is a characteristic frequency of the filter. A method is presented for stepping the value of f 0 /f f to another value and measuring f 1 /f 2 at each of these values, thereby enabling the value of f 0 to be determined.
Inventors
- 👤 Gregory M. Cutler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:50
CPC Classifications
H; H03; H03L; H03L7/00; G; G02; G02F; G02F2/00; H01; H01S; H01S3/00; H01S3/005; H01S3/0064; H01S3/10; H01S3/13; H01S3/139; H01S3/1398
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
106 words
A method of determining the value of a first frequency f0, said method comprising the steps of: (a) for a measurable frequency f f , setting the ratio of f 0 /f f to a controllable value L; (b) measuring the value f f1 of f f for L equal to an initial value L 0 ; (c) for fixed f 0 , incrementing L by a known amount Q to a value L'=L 0 +Q; (d) measuring the value f f2 or f f when f 0 =L'*f f ; and (e) calculating f 0 in terms of Q, f f1 and f f2 .
Claim 2
Independent Claim
106 words
A method of determining the value of a first frequency f0, said method comprising the steps of: (a) for a measurable frequency f f , setting the ratio of f 0 /f f to a controllable value L; (b) measuring the value f f1 of f f for L equal to an initial value L 0 ; (c) for fixed f 0 , incrementing L by a known amount Q to a value L'=L 0 +Q; (d) measuring the value f f2 or f f when f 0 =L'*f f ; and (e) calculating f 0 in terms of Q, f f1 and f f2 .
Claim 3
Dependent Claim
38 words
A method as in claim 1 wherein f 0 /f f is set to said value L in response to a control signal C 0 that is a periodic function of f 0 with period f f .
Claim 4
Dependent Claim
87 words
A method as in claim 2 wherein step (c) comprises: for k=1, . . . , p for some integer p>2 and for a set of control signals C 0 , . . . , C p , each is a periodic function of f 0 with a period f f : (f) replacing the (k-1)st control signal C k-1 with the kth control signal C k ; and (g) locking f 0 /f f to a value L k in response to the kth control signal.
Claim 5
Dependent Claim
21 words
A method as in claim 3 wherein the L k form a monotonic sequence for k=0, . . . , p.
Claim 6
Dependent Claim
28 words
A method as in claim 4 wherein C p and C 0 are identical and wherein the absolute value of L p -L 0 is equal to 1.
Claim 7
Dependent Claim
55 words
A method as in claim 5 further comprising the steps of: for m=1, . . . , q for some integer q>0, repeating steps (f) and (g) for each of k=1, . . . , p; wherein, in the gth repetition, in step (f), f 0 /f f is set equal to L 0 +q.
Claim 8
Dependent Claim
36 words
A method as in claim 3 further comprising the steps of: (h) for a known frequency f 1 , setting the ratio of f 1 /f f to a controllable value K; and (i) measuring K.
Claim 9
Dependent Claim
32 words
A method as in claim 7 wherein f 1 /f f is set to K in response to a control signal C' that is identical to one of the C k .
Claim 10
Dependent Claim
22 words
A method as in claim 8 wherein p=4 and wherein C 2 =-C 0 =-C 4 and C 3 =-C 1 .
Claim 11
Dependent Claim
10 words
A method as in claim 9 wherein C'=C 1 .
Claim 12
Dependent Claim
22 words
A method as in claim 3 wherein p=4 and wherein C 2 =-C 0 =-C 4 and C 3 =-C 1 .
Claim 13
Independent Claim
137 words
A method of varying a frequency f 0 , said method comprising the steps of: (j) for a constant frequency f f , in response to a control signal C 0 that is a periodic function of f 0 with period f f , setting the ratio of f 0 /f f to a controllable value L; (k) for k=1, . . . , p for some integer p>2 and for a set of control signals C 0 , . . . , C p , each of which is a periodic function of f 0 with a period f f : (l) replacing the (k-1)st control signal C k-1 with the kth control signal C k ; and (m) setting f 0 /f f to a value L k in response to the kth control signal.
Claim 14
Independent Claim
137 words
A method of varying a frequency f 0 , said method comprising the steps of: (j) for a constant frequency f f , in response to a control signal C 0 that is a periodic function of f 0 with period f f , setting the ratio of f 0 /f f to a controllable value L; (k) for k=1, . . . , p for some integer p>2 and for a set of control signals C 0 , . . . , C p , each of which is a periodic function of f 0 with a period f f : (l) replacing the (k-1)st control signal C k-1 with the kth control signal C k ; and (m) setting f 0 /f f to a value L k in response to the kth control signal.
Claim 15
Dependent Claim
21 words
A method as in claim 12 wherein the L k form a monotonic sequence for k=0, . . . , p.
Claim 16
Dependent Claim
28 words
A method as in claim 13 wherein C p and C 0 are identical and wherein the absolute value of L p -L 0 is equal to 1.
Claim 17
Dependent Claim
54 words
A method as in claim 14 further comprising the steps of: for m=1, . . . , q for some integer q>0, repeating steps (1) and (m) for each of k=1, . . . , p; wherein, in the qth repetition, in step (l), f 0 /f f is set to L 0 +q.
Claim 18
Dependent Claim
22 words
A method as in claim 15 wherein p=4 and wherein C 2 =-C 0 =-C 4 and C 3 =-C 1 .
References Cited (Backward Citations)
US3597699A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |