Fiber-Free Space Isolators can be divided into two categories according to its output mode: non-expanded-beam isolator and expanded-beam isolator.
The non-expanded-beam isolator consists of birefringent crystal, Faraday rotator, half-wave plate or polarizer and collimator. It's usually used in the fiber laser system to maintain the stability of optical system effectively. 
The expanded-beam isolator consists of collimator, birefringent crystal, Faraday rotator, wave plate or optical rotating mirror and beam expanding mirror. The output beam is characterized by larger spot diameter and small divergence angle.
CASTECH utilizes the high-quality crystals and optical components for the production of Fiber-Free Space Isolators to deliver great performance. The power is ranging from 300 mW to 200 W. The products are featured with high isolation(35 dB for single-stage series and 50 dB for dual-stage series), low insertion loss, excellent environmental stability and free of thermal lens effect. The beam expanders facilitate customers replacing systems with superior beam quality of desired size spots.

Applications:

•   Fabrication of fiber laser  
•  Optical fiber sensor