A technique for creating a temperature insensitive refractometer that utilizes TE and TM modes in an open-top ridge waveguide design is presented. By using the TE mode resonance as a temperature reference, the relative shift of the TM mode can be monitored in order to measure the refractive index of liquids under test. Specifically, the device fabricated here produces a relative resonance shift of 1 pm for every 1×10-4 of measured index change, with a temperature sensitivity less than 0.2 pm/°C. To increase the sensitivity of these devices, a theoretical model is developed to investigate the performance of some potential waveguide structures. Relationships between the waveguide core size, refractive index distribution, as well as the relative evanescent sensitivity of TE and TM modes are examined.

Additional Metadata
Keywords Bragg grating, Refractive index sensor, Ridge waveguide, TE and TM modes, Temperature insensitive
Persistent URL dx.doi.org/10.1117/12.732536
Conference Fiber Optic Sensors and Applications V
Citation
Dai, X., Mihailov, S.J., Walker, R.B., Chen, C, & Albert, J. (2007). Design of high sensitivity refractometer based on temperature independent TE and TM modes in open top ridge waveguides. Presented at the Fiber Optic Sensors and Applications V. doi:10.1117/12.732536