Multiparameter miniature fiber-optic sensor: design and signal interrogation

Miniature, all-silica, fiber-optic sensors capable of independent measurement of at least two different parameters are presented. Sensors were produced by a micromachining process based on the selective etching of specially designed phosphorousdoped optical fibers and an assembly-procedure that included fiber cleaving, fiber splicing and etching of fiber-micro-assemblies. Furthermore, an efficient method for independent readout of parameters in sensors that are composed of multiple resonators was also developed. The method utilizes a discrete Furrier transform of sensor’s optical spectrum and allows for simultaneous, crosstalk-free and highly sensitive readout of individual resonators’ path length changes.