Hollow-core fiber (HCF) is a special optical waveguide type that can guide light in the air or liquid core surrounded by properly designed cladding structures. The guiding modes of the fiber can ...

Traditionally, light–matter interactions generate emissive or absorptive processes, which occur when a photon induces an efficient transition between two matter states that have an energy difference ...

This is the first comprehensive review on methods and materials for use in optical sensing of pH values and on applications of such sensors. The Review starts with an introduction that contains ...

We discuss the application of the forward-mode differentiation method to Maxwell’s equations, which is useful for the sensitivity analysis of photonic devices. This approach yields exact gradients and ...