Operation of a Faraday Isolator:

A Faraday isolator consists of three main components, an input polarizer, a Faraday rotator and an output polarizer. As shown in Figure 3, light traveling 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 allow the light to pass unimpeded. As Figure 4 shows, 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 an additional 45° of nonreciprocal 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 nonreciprocal rotation while mainting a linear polarization is what differentiates it from a λ/4 plate-polarizer type isolator, and allows it to provide higher isolation.

• Introduction
  
• Operation of a Faraday Isolator
  
• Broadband Isolators for Ti:Sapphire and Other Tunable Lasers
  
• Operation of Broadband Isolators
  
• Dispersion in Ultrafast Ti:Sapphire Lasers; Sellmeiers Equation for TGG
  
• Key Optical Components of a Faraday Isolator
  
• Optical Component Specifications
  
• Isolation Defined
  
• Pulsed Damage Threshold; Root “T” Scaling