Integrated optic devices using liquid crystals: design and fabrication issues

Abstract

Integrated optic devices using liquid crystals embedded in optical waveguiding structures have advantages in terms of compactness and high performance. Such devices exploits the high electro-optic effect and the good optical properties of liquid crystals, in particular their high bireffingence and their low absorption, combined with low loss optical waveguides. Optical switches based on ion-exchanged channel glass waveguides and liquid crystals operating in the C-band used for optical communications have been designed by using beam propagation method. Polarization independent configurations are described and evaluated in terms of crosstalk and losses. Feasibility of tunable optical filters using composites materials made of polymer and nematic liquid crystals to be used in optical communication and sensor systems is demonstrated. Materials and fabrication procedures of both integrated optical switches and filters are also discussed

Infiltrated Photonic Crystal Fibers for Sensing Applications

“…Liquid crystals (LC) are a special class of fluid organic materials that show high intrinsic optical birefringence, stemming from their molecular orientational and/or positional order, which is reminiscent of solid crystalline materials. In addition, their molecular/optical axis reorientates in the presence of applied electric or magnetic fields, which makes them an excellent electro-optic material in a broad range of tunable photonic devices [160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177], including numerous examples of LC-PCF for optical switching, tunable filtering and polarization control [178,179,180,181].…”

Enhancing the Scattering Induced by Gold Periodic Arrays Over Optical Waveguides Through Indium Tin Oxide Buffer Layers

“…Low loss optical channel waveguides can be obtained with different fabrication procedures and different materials, such as SU-8 polymer [15], diffused ion-exchanged on glass and other composite materials [16], [17], [18]. Such waveguiding structures can be efficiently used to fabricate simple and cost effective integrated optic devices working in a wide frequency spectrum for optical communication and sensing systems [19], [20], [21].…”

A method for butt-coupling optical fibres to liquid crystal planar waveguides

“…However the photonic applications of LCs developed so far are mainly related to free space optics [1]; an excellent review can be found in [2]. Yet limited work exists on LC integrated guided optics [3,4]. Actually packaging and the achievement of a good interface fibre-waveguide have been a hurdle in the development of LC for integrated optics, therefore they have to be addressed specifically.…”