Fiber optic circulator
Brimrose

For application of simulating and testing of long distance fiber-optic communication lines Brimrose has developed a fiber-pigtailed AO modulator system. The recirculating loop system consists of 2 fiber-pigtailed AO modulators and a corresponding RF driver. One of the modulators is placed outside the loop to define the distance of the pulse transmission which corresponds directly to the length of the long distance fiber-optic line.

Since conventional AO device will frequency shift the transmitted light by the acoustic carrier frequency, the Brimrose approach utilizes a no-shift AO device inside the loop which does not complicate testing nor degrade system performance.