Fractal independently tunable multichannel filters

A simple fractal rule has been presented in this letter for the construction of one-dimensional photonic crystals with orthogonal defect states, which can be used as independently tunable multichannel filters. Each channel of the filters can be tuned independently. It overcomes the difficulty and provides an easy way for the design of multichannel filter with specific channels. In order to prove the validity of such a fractal rule, a series of two-channel filters have been fabricated by using a low frequency magnetron sputtering system. The experimental results agree with theoretical ones very well.