Designing voltage tunable single and multi-channel optical filter with 1DDPC nano-structure

Document Type : Research Paper


An electro-optic tunable single and multi-channel optical filter based on one-dimensional defective photonic crystal (1DDPC) structure is proposed. A couple of externally tunable defects in arrangement of (AB)5D1(BA)D2(BA)5, where A and B are dielectric materials, D1 and D2 are the tunable defects are used. The defects are composed of the ferroelectric LiNbO3 crystals and two pairs of thin Ag layers to make the voltage connections. With this arrangement it is possible to apply different external biases that facilitate the tunability and even more adjustability of the channel frequencies. Depending on the thickness of defect layers, a single or multi resonant peak can be induced inside the photonic band gap which can be employed to filter channels. About 37 nm (46 nm) of blue shift for 300 V and 37 nm (37 nm) of red shift for -300 V biases are observed without (and with) loss incorporation. An important and notable effect that happened was the dispersion loss of the structure due to metal layers is compensated by the negative biases. Our proposed structure can be good candidate to design an externally tunable optical filter and a voltage sensor with potential applications in all-optical signal processing and information communications fields.