With a specially designed probe, the phase difference between <i>s</i> and <i>p</i> polarization of light reflected under surface-plasmon resonance is measured by use of a common-path heterodyne interferometer. For specific ratios of phase difference to glucose concentration, the glucose concentration can be estimated as a function of the measured phase data. A prototype was set up to demonstrate the feasibility of this sensor, which was experimentally tested in the range 40–500 mg/dl with a small quantity of solution and had a measurement resolution of 1.41 mg/dl at 25 °C.
© 2003 Optical Society of America
(040.2840) Detectors : Heterodyne
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(240.6680) Optics at surfaces : Surface plasmons
Kun-Huang Chen, Cheng-Chih Hsu, and Der-Chin Su, "Interferometric Optical Sensor for Measuring Glucose Concentration," Appl. Opt. 42, 5774-5776 (2003)