Broadband Faraday Isolators
Standard Faraday isolators as described at our pages are ideal for fixed wavelength operation or where only occasional adjustment is required between experiments when the source wavelength has been changed. These adjustments however are relatively time consuming to make and are not convenient for some applications, such as isolating individual amplifiers in a Ti:Sapphire amplifier chain while maintaining the ability to tune rapidly over the amplifier bandwidth or isolating a femtosecond oscillator from a Ti:Sapphire regenerative amplifier, require isolators that are wavelength independent. There is not much point in having a laser source which can be tuned to a different wavelength within seconds if the Faraday isolator in the system requires removing from the bench/equipment and set up off line for optimum performance. This is where our new broad-band units come into their own.
By inserting a passive optical element (quartz rotation plate) into the device in addition to the TGG rod, the combination of the two components is an isolator in which the output polarisation is now at the more convenient angle of 90° with respect to the input. More importantly, it can be shown, that the isolation of the unit is now maintained over a wide bandwidth instead of at just one wavelength. Our first offering is designed for use over the range of wavelengths covered typically by the very important Ti:Sapphire laser source, that is 700nm to 900nm. Over this range, the isolation should remain greater than 30dB without any retuning being required. There is a small penalty to pay in that the transmission over the band is not uniform due to the varying degree to which the combined rotation of the Faraday rod and the quartz rotator matches the outgoing polarisation axis to the preferred axis of the output polariser.
With help of tables below You can choose for Your needs our stadard broadband isolator or specify Your special wishes. We offer broadband isolators within waverange from 500 to 1250 nm with apertures from 3 to 12 mm. This model also has modifications High Transmission and Site Exit.