Many industrial and scientific laser systems require high-performance optical isolators for efficient optical separation between the user application and the high-power laser amplifiers, and for preventing dangerous light feedback into a laser cavity. The magneto-optical material is the key element inside the Faraday isolator.
A group of researchers from the Numerical Modeling team, led by Dr. Slezák, and the National Instituite for Fusion Sciences (NIFS), Gifu, Japan has successfully characterized the magneto-optical properties of a Potassium Terbium Fluoride (KTF) crystal. This crystal has been manufactured by the company Northrop Grumman (NG) Synoptics based in North Carolina (US). The experimental setup was jointly designed by the HiLASE and NIFS teams. The measurements of the Verdet constant have covered a large spectral range from 600 to 1500 nm and temperatures from 15 to 295 K. These measurements, together with the well-known low values of thermally-induced stress birefringence, make KTF an ideal candidate for the next generation of high-average-power Faraday isolators. The results were recently published in Optics Letters (vol 45, No.7, 1 April 2020, pp. 1683-1686).
Future plans include further investigation of high-quality KTF crystals with different crystallographic orientations. With support of research from the Technology Agency of the Czech Republic (TA ČR), the HiLASE team has developed a high-performance functional sample of a 100 W Faraday Isolator. HiLASE is now looking for industrial partners interested in the commercialization of high-average-power Faraday Isolators.
For more details please contact solutions@hilase.cz.