solators Circulators
Isolators & Circulators
solator: Definition An isolator is a device that allows light to pass along a fibre in one direction but not in the opposite direction
Isolator: Definition • An isolator is a device that allows light to pass along a fibre in one direction but not in the opposite direction
Application coupling a laser to a fibre Reflected light can cause instability in the laser and cause many undesirable effects high speed communication system optical amplifiers fibre ring cavity
Application • coupling a laser to a fibre. Reflected light can cause instability in the laser and cause many undesirable effects. • high speed communication system • optical amplifiers • fibre ring cavity
The Faraday Effect Light travelling within the material has its plane of polarisation (electric and magnetic field vectors)rotated by an amount depending on the length and he strength of the magnetic field the most important aspect is that the effect is asymmetric materials: YIG(Yttrium-Iron-Garnet
The Faraday Effect • Light travelling within the material has its plane of polarisation (electric and magnetic field vectors) rotated by an amount depending on the length and the strength of the magnetic field. • the most important aspect is that the effect is asymmetric. • materials : YIG (Yttrium-Iron-Garnet)
Simple Isolator Forward Direction Polarising filter Polarising filter Faraday Rotator (rotated 45 degrees) (vertical) Electric Field Electric Field Direction Direction Reverse direction Electric Field Electric Field Direct irection
Simple Isolator