Channel Equalization and Bandwidth Tuning Using a LC-Based Tunable Hybrid Birefringent Filter

Abstract

International audienceWe propose and demonstrate a new modified Lyot filter to independently ensure the channel amplitude equalization and the bandwidth tuning functions. The device consists of hybrid liquid crystal interferometers. We show numerically and experimentally that for a modified four-stage Lyot filter, the two first interferometers ensure equalization function with a maximum extinction ratio, while the last interferometer allows full-width at half-maximum tuning function by using, in particular, the optical canceling approach. Such a device is highly desirable in optical telecommunications, especially where in the core network the optical filters must perform several other functions in addition to their basic amplitude filtering action

Supramolecular Assembly of Bis(benzimidazole)pyridine: An Extended Anisotropic Ligand For Highly Birefringent Materials

“…A birefringent material occurs when the difference of two primary refractive indices of the material is non-zero. [1][2][3] Birefringent materials are exploited in many applications, including NLO phase matching, [4][5][6][7] optical filters, [8][9][10][11] and optical components such as quarter-wave plates used to form circularly polarized light. [1][2][3] Despite this, little research has focused on the rational design of solid birefringent materials.…”

Birefringent, emissive coordination polymers incorporating bis(benzimidazole)pyridine as an anisotropic building block

“…[6][7][8][9] Birefringence is a physical property that can be tuned using coordination polymer synthetic methodology. [10][11][12] Birefringence occurs when the refractive indices in different directions of a material are different; [13][14][15] this property is utilised in many applications, including NLO phase matching, [16][17][18][19] optical filters, [20][21][22][23] and optical components such as quarter-wave plates used to form circularly polarized light used in the telecommunications industry. [13][14][15] To target the synthesis of a birefringent material, it is worth analyzing the factors influencing the refractive index.…”

Structural Design Parameters for Highly Birefringent Coordination Polymers

“…Birefringence (Δ n ) arises when the refractive index ( n ) depends on the direction of light propagation through a medium; it is therefore a fundamental property of anisotropic materials. − Birefringent crystals are used as optical filters, − as quarter-wave plates for generating circularly polarized light, − and in NLO phase matching. − According to the Lorentz–Lorenz equation, the refractive index is determined by both the density and polarizability of a material; birefringence is the manifestation of the orientation-dependent differences in the two quantities. − If light traveling through a material interacts with a greater number of atoms and/or more highly polarizable atoms in one direction, its propagation will be slower along that path . As such, birefringence can be tuned by tailoring a material’s polarizability and density anisotropies in order to maximize the differences in light retardation along different vectors.…”