Tunable Multichannel Filter in a Photonic Crystal Containing Semiconductor Photonic Quantum Well

A tunable multichannel filter in the finite photonic crystal (PC) containing photonic quantum well (PQW) as a defect is proposed. The symmetric structure (AB)(P) (CD)(Q) (BA)(P) and the asymmetric structure (AB)(P) (CD)(Q) (BA)(P) are considered in this work. Here, the host PC of (AB)(P) is made of Si for layer A and of SiO2 for layer B. In the PQW, (CD)(Q), C also is Si, but D is an extrinsic semiconductor, n-type silicon (n-Si). With the use of n-Si, it is found that both structures can function as a tunable multichannel filter in the infrared region. The number of channels is equal to Q + 1 in the symmetric structure, whereas it is Q for the asymmetric one. The positions of multiple resonant peaks can be tuned by the variation in the impurity concentration of n-Si. The proposed filter could be used to design the wavelength division multiplexer filter that is of technical use in optical communications.