Fiber-optic interferometric acoustic sensors were first proposed for US Navy applications 36 years ago. This paper will review the origin, development and deployment of these sensors. Future applications will also be discussed.
A key analog fiber-optic link parameter for RF and microwave antenna remoting is conversion gain or loss, which is a measure of the output RF power to the input RF power at the modulator. The link conversion loss can be minimized by using high-power lasers, modulators with low drive voltages, and sensitive photodetectors. It is highly desirable to achieve link gain without RF amplification. This has not been possible for broadband operation due to the required modulator drive voltages.
This paper reports on the development of optical waveguide modulators that can achieve subvolt drive voltages to frequencies of approximately 20 GHz. Long interaction length, multipass LiNbO<sub>3</sub> serpentine modulators have been fabricated employing low optical loss compact 180° turns. A record minimum RF loss achieved with a novel bridge structure electrode and used in these high performance modulators is presented. These modulators when connected to conventional antennas, operate as optical fiber electric field sensors.
Conference Committee Involvement (1)
20th International Conference on Optical Fibre Sensors