Phase-interrogation surface plasmon resonance biosensor based on a dynamic spectroscopic ellipsometer

This paper describes a phase-sensitive high-throughput surface plasmon resonance (SPR) biosensor based on a dynamic spectroscopic ellipsometer. The proposed scheme enables dynamic extraction of spectroscopic ellipsometry parameters from a single spectrum acquisition using a monolithic polarizing interferometer with a spectral carrier frequency, thereby eliminating the need for active polarization modulation components. The proposed phase-sensitive SPR biosensor with a calibration path significantly reduces the inherent polarization-phase drift of the one-piece interferometer module, providing a polarization-phase fluctuation of σSD = ±0.05°. We demonstrate experimentally that the proposed biosensor system can provide a limit of detection of 1.4 × 10−6 RIU with a sensing speed of around 1 Hz.