Slow-Light Enhanced Liquid and Gas Sensing Using 2-D Photonic Crystal Line Waveguides-A Review

Photonic crystals (PhCs) are periodically structured dielectric materials that have attracted significant research interest in the last two decades for their ability to slow down the group velocity of a propagating pulse envelope with promising sensing applications. This review article discusses the properties of 2-D PhCs including the slow-light phenomenon, bandgap generation, and application of these properties for gas and liquid sensing. Waveguide generation by introducing defects with light guiding and confinement is discussed. In addition, for 2-D PhC line waveguides, a comprehensive review on the slow-light principle and phenomenon of slow-light enhanced sensing for gases and liquids is discussed. 1-D and 3-D PhCs are also reviewed for bandgap generation and defects in PhCs along with present fabrication challenges and future trends. Our study highlights an increase in the detection capabilities of PhC-based sensors paving way for high-sensitivity detectors with applications in ubiquitous monitoring of gases and liquids.

Automated summary

This review article discusses the properties and applications of photonic crystals, with a focus on slow-light phenomenon and enhanced sensing for gases and liquids. It also discusses the challenges in fabrication and highlights the importance of high-sensitivity detectors for ubiquitous monitoring.