Multifunctional highly dispersive mirror for fiber oscillator

Abstract

Dispersive mirrors are generally used as reflective elements in ultrafast laser systems. In this study, a multifunctional highly dispersive mirror (MFDM) was prepared on the fiber tip, providing high transmittance in the pump wavelength, partial reflection and dispersion compensation in the working band. To achieve this, a starting structure that combines a quarter-wavelength structure, multi-cavities, and an anti-reflection structure was proposed. A large amount of dispersion was introduced while maintaining a certain reflectivity in the range of 1,050–1,060 nm and high transmittance at 976 nm. Employing the input and output coupling mirror as a dispersive mirror for the first time, the MFDM was successfully applied to an all-fiber oscillator to generate ultrafast seed pulses. This unprecedented MFDM is expected to replace dispersion compensation fibers, opening an avenue for the development of compact fiber lasers.