Polarization independent optical switch
First Claim
1. A polarisation independent optical switch comprising a light input (6), a diffractive and re-configurable liquid crystal device (8), a collimating lens (7) for distributing the input light over the liquid crystal device (8), a transform lens (9) receiving light from the liquid crystal device (8) and a light output (6), wherein no polarisers are present between the light input and output, characterised in that the diffractive and reconfigurable liquid crystal device (8) is a liquid crystal spatial light modulator configured as a computer generated hologram and wherein a change in switched state of an area of the spatial light modulator causes a change in the state of polarisation of light which emerges from that area of the spatial light modulator.
2 Assignments
0 Petitions
Accused Products
Abstract
A polarisation independent optical switch is constituted by a light input (6), a diffractive and re-configurable liquid crystal device (8), a collimating lens (7) for distributing the input light over the liquid crystal device (8), a transform lens (9) receiving light from the liquid crystal device (8) and light output (6), wherein no polarisers are present between the light input and output. The diffractive and re-configurable liquid crystal device (8) may be formed as a liquid crystal spatial light modulator configured as a binary phase computer generated hologram with the holograms required to form broadcast, individual or multicast switching being re-generated using an iterative algorithm and then being recalled on demand. In one embodiment the switch has a folded configuration and includes a reflector (10) so that the light input and output are both on the same side of the liquid crystal device (8).
36 Citations
10 Claims
- 1. A polarisation independent optical switch comprising a light input (6), a diffractive and re-configurable liquid crystal device (8), a collimating lens (7) for distributing the input light over the liquid crystal device (8), a transform lens (9) receiving light from the liquid crystal device (8) and a light output (6), wherein no polarisers are present between the light input and output, characterised in that the diffractive and reconfigurable liquid crystal device (8) is a liquid crystal spatial light modulator configured as a computer generated hologram and wherein a change in switched state of an area of the spatial light modulator causes a change in the state of polarisation of light which emerges from that area of the spatial light modulator.
Specification