Patent ID: 6901175
Filing Date: 2005-05-31
Classification: G02B,G02F

Abstract:
1. A device for filtering at least a predetermined selected optical signal having a predetermined wavelength range from a series of optical signals, the device comprising: a polarisation alignment means for substantially aligning substantially orthogonal polarisation states of an optical input signal so as to produce a polarisation aligned optical signal; a polarisation manipulation means for imparting a controlled polarisation manipulation to said polarisation aligned optical signal so as to output a polarisation manipulated optical signal having one of at least two distinguishable polarisation states including a first polarisation state and a second polarisation state; an optical separation means tunable liquid crystal etalon filter having a tunable separation wavelength for spatially separating the selected optical signal from said series of optical signals when the polarisation state of the polarisation manipulated optical signal is in a first polarisation state, thereby forming a first and second output optical signal, and maintaining the spatial alignment of said selected optical signal with said series of optical signals when the polarisation manipulated optical signal is in a second polarisation state so as to form a third optical output.