SBIR-STTR Award

TThe U.S. Navy is seeking an electromagnetic (EM) field sensor capable of operation in the frequency range of 10 khz to 60 khz, which can be covertly deployed from a submarine platform. Optical technologies, inc. (Optech), proposes a fiber-optic em-field sensor to meet this need. The sensor has the following major features: atmospheric noise limited performance; immunity to effects of electromagnetic pulse (EMP); immunity to electromagnetic interference (EMI) in the optical fiber lead; multimode laser optical source to provide stable laser operation (eliminates mode hopping), and single optical fiber construction to reduce the amount of fiber required in lead and sensor element.

Optical Technologies, Inc. (Optech) proposes to develop a fiber-optic magnetometer for underwater bore-hole use. The design, development and fabrication of a manufacturing prototype will be carried out during this effort. Testing will be performed both in the laboratory and at an underwater site. In addition, a triaxial version of the fiber-optic magnetometer will be designed and the alignment and calibration procedures specified. The characteristics of the proposed device are listed below, namely: a) frequency range from 0 to above 100 hz; b) accuracy of between 0.1 and 1.0 gamma or better; c) resolution of 0.01 to 0.1 gamma or better; d) long term stability; e) immunity to mechanical and acoustic noise as well as thermal drifts. These by no means represent the ultimate characteristics but are those required for the particular underwater bore-hole use considered here. As an example accuracies 1 or 2 orders of magnitude better that those listed in (b) are indicated by experimental studies at optech.