The LINOS Faraday Isolators - Qioptiq Q-Shop

Faraday IsolatorsAdvantages of Faraday IsolatorsIsolatorsHigh IsolationThe properties of the Faraday isolatorare determined by the quality of theoptical elements and the uniformity ofthe magnetic field. The entrance and exitpolarizers exhibit a very high extinctionratio, so that the isolation is mainlylimited by inhomogenities in the crystalmaterial. Specially selected crystalmaterials with a high Verdet constantcombined with permanent magnets witha high remanence enable us to useshorter crystals and obtain an isolation> 30 dB.The radiation blocked by the entranceand exit polarizers is not absorbedinternally, but is deflected by 90° withrespect to the beam direction. Thisensures a stable thermal operation evenat higher laser power levels. The blockedradiation can be used for other applications.All optical surfaces are slightlytilted relative to the beam axis.Low Insertion LossThe high transmission, typically > 90 %,is achieved by using absorption freematerials and antireflective coatings withlow residual reflectivity on all entranceand exit surfaces.large aperturecompact designhigh isolationLarge Aperture, Compact Designlow insertionlossAll optical elements have been alignedto eliminate beam shading and allow foreasy adjustment. Focusing is notnecessary.The compact design is achieved by usingrare earth magnets with the highestremanent magnetism and TGG crystalmaterial with a high Verdet constant.The isolator is suitable for divergentbeams or in setups with limited space. Aminimal optical path length in theisolator results in the lowest possibleinfluence on the image.Three sides of the entrance and exitpolarizers are usable and readilyaccessible for easy cleaning. The degreeof isolation can be adjusted in a widerange.Mounting FlexibilityThe isolators can be mounted directly viathreaded holes in the housing or viaadditional base plates or angle brackets.ApplicationsThe ongoing development and refinementof laser technology have created aneed for optical components that shieldthe laser resonator from back reflections.Faraday isolators provide an efficientmethod of suppressing instabilities andintensity fluctuations in laser devices.Typical applications are:••Protection of the resonator in solidstate and gas lasers from backreflections••Prevention of parasitic oscillation inmultistage solid state amplifiers••Protection of diode lasers against backscatter and extraneous lightGermany-Phone: +49 (0) 551/ 6935-0 France-Phone: +33 - 47 25 20 420629