(12) United States Patent ao) Patent No.: Us 7,676,153 Bi
Seetharaman et al. (45) Date of Patent: Mar. 9,2010
(54) DIGITAL DELAY DEVICE
(75) Inventors: Guna Seetharaman, Dayton, OH (US);
Paul E. Kladitis, Edwards, CA (US)
(73) Assignee: The United States of America as
represented by the Secretary of the Air
Force, Washington, DC (US)
( * ) Notice: Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
U.S.C. 154(b) by 1152 days.
(21) Appl.No.: 11/251,192
(22) Filed: Oct. 17, 2005
(51) Int. CI.
(52) U.S. CI 398/45; 398/53; 385/18
(58) Field of Classification Search 398/53,
398/102, 161, 45, 51, 54; 385/18, 19, 17 See application file for complete search history.
(56) References Cited
U.S. PATENT DOCUMENTS
A digitally controlled optical delay apparatus providing optical signal delays electrically selectable in the picosecond to nanosecond range by way of selectable signal path lengths. Path lengths are incremented in physical length and path delay time according to digital ratios. The delay element includes micro-miniature path changing mirrors controlled in path length selecting positioning by input signals of logic level magnitude. Fiber optic coupling of signals to and from the delay element and a combination of fixed position and movable mirror included optical signal path lengths are included.
19 Claims, 5 Drawing Sheets