Applied Physics B

, Volume 54, Issue 1, pp 18–23

An integrated optical sensor for measuring glucose concentration


  • Y. Liu
    • Center for Advanced Studies and Department of Physics and AstronomyUniversity of New Mexico
  • P. Hering
    • Max-Planck-Institut für Quantenoptik
    • Institut für LasermedizinUniversität Düsseldorf
  • M. O. Scully
    • Center for Advanced Studies and Department of Physics and AstronomyUniversity of New Mexico
    • Max-Planck-Institut für Quantenoptik

DOI: 10.1007/BF00331729

Cite this article as:
Liu, Y., Hering, P. & Scully, M.O. Appl. Phys. B (1992) 54: 18. doi:10.1007/BF00331729


We used an optical sensor combined with a Mach-Zehnder interferometric waveguide and optical fibers to measure slight changes of aqueous sugar concentrations. The merits of this sensor are simplicity, reliability, high sensitivity and continuous monitoring. The technique is based on the fact that the refractive index of sugar solution changes with the concentration of sugar. In the experiment, one arm of the interferometer is clad with glue and is thus isolated from the sugar solution. The other one is exposed to the sugar solution. A single mode fiber is directly glued onto the interferometric waveguide, to guide the light into the interferometer. If the concentration of sugar covering the waveguide changes, the phase of propagating light in the exposed arm will be changed, while the phase in the other arm is fixed. Hence the output intensity from the interferometer is directly related to the concentration of the sugar solution. The result of this experiment yields the relation between the sugar concentration and output signal. From 0% to 1% concentration of sugar solution, there is only a 1.4×10−3 refractive index difference. Two sets of experimental data have been obtained, showing a linear relation between the sugar concentration and the output signal from our sensor. This sensor could be used for continuous monitoring of blood sugar in the human body.



Copyright information

© Springer-Verlag 1992