Optical waveguide biosensors are attracting more and more attentions and presenting great potential applications.
Polymer-based optical biosensors are promising for the their unique advantages: low cost, easy fabrication,
possibility of functionalization with chemicals for the detection of biological molecules, and flexible operating
wavelength in both the infrared communication wavelength band (1310-1550nm) and the visible wavelength region
(500-800nm). Operating in the visible wavelength, the optical biosensing can avoid the high optical absorption loss
of water solution, which can hardly be done for Si-based optical sensors. In this paper, an optical biosensor utilizing
polymer-based athermal optical waveguide microring resonator is presented. The athermal design of the microring
resonator can make the resonant wavelength drift with temperature be greatly reduced, and an optical biosensing
platform with high thermal stability can be achieved. The simulation results show that the maximal resonant
wavelength drift is -0.0085nm when the temperature varies from 20°C to 65°C and the maximal wavelength drift
slope is -0.0009nm/K. With the microring resonators fabricated by using a simple UV based soft imprint technique
with self-developed UV-curable polymer PSQ-L materials, experimental investigations on the specific surface
detection of target molecules have been preliminarily performed. The results shows that the optical biosensors
based on the polymer optical microring resonators would have potential applications for label-free surface sensing.