Experimental study on the performance of a variable optical attenuator using polymer dispersed liquid crystal

Abstract

We applied polymer dispersed liquid crystal (PDLC) as the cladding material in a polymer-based variable optical attenuator. Three polymer inverted channel waveguides were fabricated, two with PDLC upper cladding (aligned PDLC and nonaligned PDLC) and one with aligned liquid crystal upper cladding. Upon operation, the waveguides with aligned upper claddings show relatively lower threshold and cutoff voltages compared to those with nonaligned PDLC cladding. But the waveguide with nonaligned PDLC upper cladding shows lower polarization dependence and a higher attenuation range of 39 and 41.37 dB for TM and TE modes, respectively, over a tuning field strength of 0.9 V/μm.

FDTD Modelling of Silver Nanoparticles Embedded in Phase Separation Interface of H‐PDLC

“…As a new type of electrooptical material, holographic polymer-dispersed liquid crystal (H-PDLC) has many potential applications in optical communications, flat panel displays, information storage, and integrated optics [7][8][9][10][11][12][13]. A number of practical and effective instruments have been fabricated based on the unique characteristics of H-PDLCs such as optical attenuator, holographic zoom lens, and holographic volume gratings [14][15][16][17][18][19][20]. Two coherent recording beams create a sinusoidal interference optical pattern, which leads to periodic phase separation between prepolymer monomers and liquid crystal (LC).…”

Effect of TiO2 nanoparticle doping on the performance of electrically-controlled nematic liquid crystal core waveguide switch

“…Doping with nanoparticles can change the performance characteristics of LCs, such as electro-optic and dielectric properties, memory effect, and phase behavior. Various types of nanoparticles such as metallic [9], semiconducting [10], ferroelectric [11,12], carbon nano-tubes [13,14], dielectric and insulating [15][16][17][18][19] have been developed in recent years to realize LC nanocolloids. Several reports [20][21][22] have shown that doping of a nematic LC with small amounts of nanoparticles affects the properties of nematic LC such as the decrease of threshold and switching voltages, and switching time of the device.…”

Hybrid organic–inorganic materials for photonic applications

“…Specifically, this feature issue consists of 14 papers comprising four sections: liquid crystals (Lorenz et al [1], Rudzki et al [2], Garbovskiy and Glushchenko [3], Lavrič et al [4], and Yaroshchuk et al [5]); polymers (Nabil et al [6], Minasyan and Galstian [7], Uklein et al [8], Nazarova et al [9], and Sassa et al [10]); photoconductive materials (Bortolozzo et al [11] and Mercado-Zúñiga et al [12]); and gratings and filters (Sheremet et al In the first section, Lorenz et al [1] investigated the influence of ferroelectric nanoparticles on the realignment of the LC director upon the application of an electric field. In this invited paper, LC nanodispersion with BaTiO3 ferroelectric nanoparticles showed a more pronounced reorientation with a reduced threshold voltage compared to the undoped LC.…”

“…Nabil et al [6] applied polymer dispersed liquid crystal (PDLC) as cladding material in a polymer-based variable optical attenuator. The PDLC-based waveguide was electro-optically modified at low operating voltages without the need of alignment layer as in the case of LC.…”