Microcavities in Photonic Crystal Waveguides for BiosensorApplications

摘要

In this study, resonant microcavities in photonic crystal (PhC) waveguides are investigated for biosensing applications.The device architecture consists of a PhC waveguide with a defect line for guiding the transmission of light. Resonantmicrocavities created by changing the radius of a hole adjacent to the defect line are coupled to the PhC waveguide.Detection is based on shifts in the resonance wavelength observed in the transmission spectra. The PhC waveguidedevice is fabricated on silicon-on-insulator (SOI) wafers using electron beam lithography and reactive-ion etching (RIE).Receptor molecules are attached to the defects in the device by standard amino-silane and glutaraldehyde crosslinkingchemistry. Preliminary results demonstrate successful detection of human IgG molecules as the target at largeconcentration levels of 500 μg/ml. Such PhC waveguide devices are advantageous for medical diagnostics andbiosecurity applications as they allow rapid, label-free, and sensitive detection of multiple analytes single platform.