Temperature Insensitive Refractometer Using Core and Cladding Modes in Open-Top Ridge Waveguide

• Published in: IEEE sensors journal Vol. 8; no. 5; pp. 451 - 456
• Main Authors: Xiaoli Dai, Walker, R.B., Mihailov, S.J., Chengkun Chen, Blanchetiere, C., Callender, C.L., Albert, J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomedical measurements; Biosensors; Bragg grating; Bragg gratings; Chemical and biological sensors; Cladding; cladding mode; core mode; Devices; Instability; Liquid waveguides; Refractive index; refractive index sensor; Refractometers; Resonance; ridge waveguide; Ridges; Sensors; temperature insensitive; Temperature sensors; Testing; Waveguide transitions; Waveguides
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2008.918172

In order to overcome the well-known limitation of temperature instability in Bragg grating waveguide sensors, a temperature insensitive open-top ridge waveguide refractometer is developed by using a cladding mode resonance as a temperature reference. The relative shift of the core mode resonance to cladding mode resonance is used to measure the refractive index of substances under test. Specifically, the device fabricated here produces a relative resonance shift of 1 pm for every 5 times10 -4 of measured index change, with a temperature sensitivity ~ 0.5 pm/degC.