Side polished optical fiber

Fig. 2.16 (a) A schematic drawing of polymer microring resonator couple to a side polished optical fiber, (b) A microscope image of the fabricated EO polymer electric field sensor, (c) SEM image of resonators fabricated on the polished flat of a free standing fiber. The scale bar in the picture represents 100 pm. Reprinted from Ref. 15 with permission. 2008 Institute of Electrical and Electronics Engineers... 

The high EO activity and solvent resistance allowed these materials to be processed through multiple lithographic and etching steps to fabricate a race-track-shaped microring resonator. By coupling this resonator with a side-polished optical fiber, a broadband electric-field sensor with a high sensitivity of 100 mV/m at 55 MHz has been demonstrated [116]. 

Other devices that can be fabricated with NLO polymers are for example sensors for electric field. A number of sensors fabricated with EO polymers to detect electric field signals and map the electric field distribution have been implemented in the last years based on Mach-Zehnder intensity and polarization modulators. Other sensors are based on asymmetric Fabry-Perot microcavities to convert phase modulation into amplitude modulation and enhance the samphng signals. Very recently Sun et al. [172] presented a novel broadband electrooptic electric field sensor fabricated with an EO polymer microring resonator coupled to the core of a side-polished optical fiber. A sensitivity of 100 mV/m has been achieved at frequencies up to 550 MHz. 

Sharma N.K., Gupta B.D., Fabrication and characterization of pH sensor based on side polished single mode optical fiber, Opt. Comm. 2003 216 299-303. 

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