Large Format Faraday Isolators for High Power Ultrafast Laser Systems

Problem: The program addresses a critical need for a kilowatt optical power isolator that is not commercially available. This ultra-high optical power isolator is a key component that enables the next generation of kilowatt-class ultrafast laser systems to use in many areas of accelerator applications. This program provides this important laser component to realize novel accelerator concepts for future colliders; in the generation, manipulation, and x-ray seeding of electron beams; in the generation of electromagnetic radiation ranging from THz to gamma rays; and in the generation of the neutron, proton, and light ion beams. With applications demanding ever higher fluxes of particles and radiation, the driving laser technology must also increase in repetition rate—and hence average power—to meet the demand. Presently, no vendor can provide a large aperture isolator with power handling exceeding kW. Objective: The program aims to develop a new generation of free-space optical isolators with significantly higher optical power handling to reach beyond kW pulse and CW operations that have not been attainable. Phase II work: Phase II will result in the fabrication of a fully functional free space isolator capable of 1 kW with transmission exceeding 95% and isolation exceeding 30 dB across the entire 5% bandwidth with an aperture size of 30mm in diameter. The isolators will be extensively tested at our in-house facility to demonstrate their optical performance and thermomechanical stability. The development will validate the advantages of the proposed novel approach and open the avenue for all wavelength high-power isolators to broaden the applications. Analysis and plan will be completed that provides a path to extend the design to 100 kW average power operation. Commercial Application: In addition to the scientific community, The proposed next-generation highpower optical isolators have direct Applications in the high-power laser commercial market. The global industrial laser market was over $3 billion last year.