A Faraday isolator consists of three main components, an input polarizer, a Faraday rotator and an output polarizer. Light travelling in the forward direction passes through the input polarizer and becomes polarized in the vertical plane. Upon passing through the Faraday rotator, the plane of polarization will have been rotated 45 on axis. The output polarizer, which has been aligned 45 relative to the input polarizer, will then let the light pass through unimpeded.
Light traveling in the reverse direction will pass through the output polarizer and become polarized at 45. The light will then pass through the Faraday rotator and experience and additional 45 of non-reciprocal rotation. The light is now polarized in the horizontal plane and will be rejected by the input polarizer, which only allows light polarized in the vertical plane to pass unimpeded.
A Faraday isolators' ability to provide non reciprocal rotation while maintaining a linear polarization is what differentiates it from a l/4 plate-polarizer type isolator, and allows it to provide higher isolation.
Our Faraday rotators/isolators' distinctive features are compact size, high transparency (>98%) and extinction ratio (35 - 40 dB). Standard models are suitable for both CW and pulse applications. We also offer rotators and isolators operating at almost any given wavelength. Customers can order Faraday rotators and isolators based on different magneto-optical materials TGG, MOS-31, MOS-33, etc. For 1-ns pulses, the damage threshold is as high as 3 GW/cm2. Large apertures available.
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