Low-cost interrogation unit for wavelength-encoded optical sensors


Bellman, K.; Kiesel, P.; Beck, M.; Johnson, N. M. Low-cost interrogation unit for wavelength-encoded optical sensors. Proceedings of the 7th International Workshop on Structural Health Monitoring 2009; 2009 September 9-11; Stanford University, CA. Lancaster, PA: DESTech; 2009; 965-972.


We have developed a low-cost, compact, fast-response wavelength detector that is well suited for the read-out of wavelength-encoded sensors. The output signal of such sensors is a direct response to an optical wavelength shift induced by an external stimulus, for example, temperature, strain, stress, acceleration, adhesion of bio-particles, or change in the chemical environment. The wavelength-shift detector has been integrated with a light source and a Fiber Bragg Grating sensor to produce a vibration sensing system. We demonstrate detection of 10 kHz vibrations with a sensitivity of ~ 1 micro strain.

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