|
In this paper, we have theoretically analyzed using a finite-difference time domain (FDTD) methods and realized a
high sensitive triangular ring resonator sensor based on the total internal reflection (TIR) mirror with a thin metal film
for surface plasmon resonance (SPR) phenomenon. One of advantages is a high sensitivity with large phase variation at
TIR mirror facet with SPR. Previously, the sensing region of the general ring resonator sensor is located on the cladding
region or upper core region. However, the triangular ring resonator has a very high sensitivity using the sensing region of
the TIR mirror facet, because the length of the evanescent field at TIR mirror is longer than the evanescent field length at
the cladding region. Another is a high Q-factor by the round-trip loss compensation through an active medium in the
waveguide. Proposed sensor also has an integrated light source using an InP-based semiconductor optical amplifier. The
sensitivity of triangular ring resonator with SPR is extremely enhanced by large phase shift at TIR mirror facet on SPR.
Optimized metal thickness is a 33.4 nm at the SPR angle of 22.92 degree. The simulation result of the sensitivity for the
triangular ring resonator sensor with SPR is 4.2×104 nm/RIU using by FDTD method. To measure the biosensor, we used
an antigen/antibody reaction.
|
