摘要 |
The invention provides a multi-cavity filter, and in particular, a multi-cavity bandpass filter having a predetermined centre wavelength. The filter includes a plurality of cavities, each cavity including two partially reflecting films separated by a layer of dielectric material. The two partially reflecting layers are formed from layers of material having alternating high and low refractive indices. Each layer of dielectric material has a thickness that is an integral number of half-waves of the centre wavelength. The filter has an asymmetric structure that causes the reflected chromatic dispersion from one side of the filter to be reduced relative to the reflected chromatic dispersion from the other side.
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