Characteristics of Sensor Response of a Difference Interferometric Slab Optical Waveguide Refractive Index Sensor with a Prism Coupling Method

Fabrication of sucrose biosensor based on single mode planar optical waveguide using co-immobilized plant invertase and GOD

“…The biomaterial can be cladded on the surface of guide, where the clad acts as an interacting region to control the evanescent mode losses. For biological application, immobilized enzymes (Gouda et al, 2002;Gursel et al, 2003;Danisman et al, 2004;D'Souza and Godbole, 2002), proteins (Tsunoda et al, 1999;Cross et al, 2003) and other biomolecules such as antibodies (Adanyi et al, 2006;Lukosz et al, 1991) and peptides are now extensively used for immobilization.…”

Lock-in Modulation Detection for a Difference Interferometric Slab Optical-Waveguide Refractive-Index Sensor

“…1c. When ψ is set to π/4, based on previous work 5 and polarizer A (φ (t)) is rotated as an optical chopper, eq. (2) can be rewritten as…”

“…The SOWG system was basically the same as that described in a previous paper. 5 As shown in the figure, a He-Ne laser (632.8 nm, 2 mW, random polarization) was used as a light source. A polarizer (P) and a λ/4 phase plate were placed between the SOWG and the light source.…”

“…The D0 value could change in each experimental setup, and optimization of the measurement conditions was a tedious task. 5 On the other hand, other researchers have used rather complex detection systems to avoid such a problem; multiple photo-detectors systems or a charge-coupled device (CCD) camera system were applied when complicated signal processing was required. [1][2][3][4] In this paper, we describe a simple detection system for the RI sensor using lock-in modulation.…”

“…Although we applied an absorbance detection system to the RI sensor in previous work, 5 its sensitivity was dependent upon the D0 value in Eq. (2) in the Theory section; the D0 value is involved in the coefficient in the expression for the relation between the absorbance and the RI change of the sample solution.…”