PM Optical Attenuator

Fibermart's Polarization Maintaining Variable Optical Attenuator PM VOAs allow the users to vary the attenuation of a signal for precise power balancing in fiber circuits or evaluation of dynamic range of measurement systems. Adjustment of the PM attenuation is achieved using the thumbscrew on the top of the housing module.

The Fibermart pm optical attenuator is comprised of an input fiber, collimating lens, blocking device, focusing lens, and output fiber. By turning the thumbscrew, the blocking device is shifted into the beam path, blocking part of the free-space beam (refer to the schematic to the right). Then, a second lens is used to couple light into the output fiber. Therefore, by turning the screw, one can manually alter the coupling efficiency until the desired attenuation is obtained.