Resonant Wavelength Shift Detection System Based on a Gradient Grating Period Guided-Mode Resonance

A resonant wavelength detection system based on a gradient grating period guided-mode resonance (GGP-GMR) filter and a linear charge-coupled device is demonstrated. The GGP-GMR used in this work consists of a subwavelength grating structure with a grating period that varies from 250 to 550 nm in increments of 2 nm. We successfully demonstrate that by using this system, we can monitor the shift in a sensor's dip wavelength caused by different sucrose concentrations. This technology has the potential to replace the spectrometer used in most optical biosensor systems. Given its compactness, the system can be integrated with lab-on-a-chip systems for numerous biosensing applications.