Patent ID: 8526097

Claim:
A tunable bandwidth selector, comprising: a first structure adapted to receive an input spectrum substantially along a first axis, the input spectrum having a plurality of electromagnetic waves; and a second structure adapted to selectively alter the path of a first portion of the input spectrum, wherein said second structure includes a grating structure which is adjustable to vary a bandwidth of the first portion of the input spectrum, the grating structure having a variable index of refraction and a variable spacing; wherein the grating structure is produced by a plurality of spaced apart electron sheets; wherein the variable spacing of the grating structure is accomplished by varying a number of the plurality of spaced apart electron sheets; wherein a first portion of the plurality of spaced apart electron sheets are produced by at least a first electron source and a second portion of the plurality of spaced electron sheets are produced by at least a second electron source, the number of the plurality of spaced apart electron sheets being reduced by deactivating the at least second electron source.