FIBER-OPTIC SENSOR RESTORATION SYSTEM FOR NUCLEAR POWER PLANT MONITORING

To expand the application scope of fiber-optic sensors in nuclear power plants, it is necessary to solve the technical problem of a sharp increase in optical attenuation under ionizing radiation conditions, resulting from radiation-induced darkening of the waveguide material. Optical stimulation is one of the most effective factors for inducing the decay of radiation-induced color centers and reducing radiation-induced coloration in irradiated glass. Retunable lasers have demonstrated high effectiveness in the photostimulation of irradiated glass. This study presents a design concept for a ring quantum cascade laser (QCL) with piezoelectric control that combines single-mode continuous tuning, characteristic of DFB lasers, with an extended tuning range. The proposed laser uses a single ring QCL with a tunable diameter. The ring is coupled to a bus waveguide. This configuration allows multi-ring spectral scanning while maintaining stable emission through unidirectional lasing. Unlike traditional tunable lasers, the device achieves mode-hop-free tuning over a broad spectral range, is robust to high levels of optical feedback, and supports laser-beam combining to provide broad spectral coverage.