Granted Patent
Utility
US 4,751,690 · App. 06/861,947
Fiber optic interferometric hydrophone
Inventor:
Helmut H. A. Krueger
Patented Case
View Patent ↗
Granted: Jun 14, 1988
Filed: May 12, 1986
Inventor
Helmut H. A. Krueger
Assignee (at issue)
Gould Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.