Birefringence dispersion of 6CHBT liquid crystal determined in VIS-NIR spectral range

• Published in: Applied surface science Vol. 542; p. 148525
• Main Authors: Tarjányi, Norbert, Veveričík, Marek, Káčik, Daniel, Timko, Milan, Kopčanský, Peter
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2021
• Subjects: 6CHBT; Group birefringence; Nematic liquid crystal; Phase birefringence; Polarization; Polarization; Nematic liquid crystal; 6CHBT; Phase birefringence; Group birefringence
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.148525

[Display omitted] •Birefringence dispersion of pure 6CHBT liquid crystal in VIS and NIR is determined.•From the phase birefringence dispersion the group birefringence is calculated.•The existence of two absorption bands in the UV region is assumed in the model. The dispersion dependence of the birefringence of optical materials is important for many practical applications. However, it seems that such measurements are rare for some kinds of liquid crystals. The paper aims to partially fill the gap by investigating the dispersion dependence of the group and phase birefringence of a pure 6CHBT liquid crystal sample at a constant temperature. The inner surfaces of the cell containing the investigated 6CHBT liquid crystal sample were specially treated to have the molecules aligned parallel to the cell’s surfaces with no pretilt. The group and phase birefringence of the liquid crystal was investigated in the wavelength range of (400–800) nm and (900–1800) nm using a house-made planar polariscope. Analysis of the measured spectra yielded dispersion dependencies of group and phase birefringence.