Photo-aligned ferroelectric liquid crystals in microchannels

Abstract

In this Letter we disclose a method to realize a good alignment of ferroelectric liquid crystals (FLCs) in microchannels, based on photo-alignment. The sulfonic azo dye used in our research offers variable anchoring energy depending on the irradiation energy and thus provides good control on the FLC alignment in microchannels. The good FLC alignment has been observed only when anchoring energy normalized to the capillary diameter is less than the elastic energy of the FLC helix. The same approach can also be used for the different microstructures viz. photonic crystal fibers, microwaveguides, etc. which gives an opportunity for designing a photonic devices based on FLC.

Improving the electric field sensing capabilities of the long-period fiber grating coated with a liquid crystal layer

“…However, the variety of LCs is large. Ferroelectric LCs [24] or lyotropic chromonic LCs for biological sensing application [25,26], are only a few examples of LC materials that might be used in combination with LPFGs to enhance their tuning properties. It could be also interesting to fabricate a LPFG based on the fiber made of high-index glass.…”

Photo‐aligned photonic ferroelectric liquid crystal fibers

“…The detailed description of preparation of the photo-aligned MCs infiltrated with FLC material FD4004N has been reported previously. 29 It was demonstrated that the SD1 material gives excellent and stable alignment for FLCs. Based on the results described in the work of Budaszewski et al (2014), 29 we have repeated the procedure of making photo-aligned layer in the PM-1550-01 PCF.…”

“…Previous investigations proved that the exposure energy of ~3 J/cm 2 at wavelength λ = 450 nm would be sufficient to provide the required anchoring energy for FD4004N FLC inside investigated MC. The detailed description of preparation of the photo‐aligned MCs infiltrated with FLC material FD4004N has been reported previously . It was demonstrated that the SD1 material gives excellent and stable alignment for FLCs.…”

“…Based on the results described in the work of Budaszewski et al . (2014), we have repeated the procedure of making photo‐aligned layer in the PM‐1550‐01 PCF.…”

Birefringence measurement of polymer photonic crystal fibers infiltrated with liquid crystals by depolarization of light effect

“…However, high attenuation and sensitivity for damage can be considered as a disadvantage of mPOFs. The vast majority of research studies have been devoted to the infiltration of a PLCF microstructure with nematic LCs, but recently also PLCFs infiltrated with smectic C* LCs have been reported [11].…”