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(AB)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.