Leaky waveguides (LWs) for chemical and biological sensing−A review and future perspective

This review provides a historical perspective along with a tutorial on the concepts, instrumentation, and progress in the chemical and biological sensing applications of leaky waveguides (LWs) . The review compares the sensing performance (i.e. refractive index sensitivity, figure of merit, refractive index resolution, and absorption/scattering/fluorescence sensitivity) of LWs with other label-free optical sensors. As the porosity of the waveguide layer is a primary factor in determining the sensing performance of the LWs, different materials and fabrication methods used to make porous films are also reviewed. Finally, we have discussed the challenges that need to be addressed and the opportunities that can be availed for the development and adoption of LWs for chemical and biological sensing at point-of-need (PoN).