laserabsorbent

A laserabsorbent is a material or coating engineered to absorb incident laser radiation within a defined wavelength range. By converting absorbed light into heat or charge carriers, laserabsorbents reduce reflectance and transmission, helping manage laser energy in applications such as protection, sensing, and processing.

Key properties include a high absorption coefficient at target wavelengths, suitable thermal conductivity, a high damage threshold, chemical and environmental stability, and spectral selectivity. Some laserabsorbents exhibit nonlinear absorption, enabling functions such as optical limiting at high fluences.

Materials used as laserabsorbents range from carbon-based substances (graphene, carbon black), metal oxides and plasmonic nanoparticles to organic dyes and specially engineered multilayer coatings. Absorption mechanisms can be linear, where absorption scales with light intensity, or nonlinear, where absorption increases with input intensity or saturates at high levels to protect underlying components.

Applications include laser safety coatings and eyewear, protective layers on optical sensors, optical-limiters to shield cameras or detectors, and coatings on laser-processing tools to control reflected or stray light. In biomedicine, photothermal agents used as laserabsorbents can convert light to heat for therapy, under controlled conditions.

Challenges involve achieving broad or tunable wavelength coverage while maintaining a high damage threshold, ensuring long-term stability under laser exposure, managing heat generation, and avoiding degradation under environmental conditions. Cost and compatibility with substrates also influence practical deployment.

Related concepts include optical limiters and saturable absorbers, laser safety, and photothermal materials.