Liquid Crystals in Metamaterials

High Birefringence Liquid Crystals

“…The main area of application for very high birefringence LC is in infrared spectral range [16][17][18] and recently, the interest is also gained to GHz and THz ranges. They are connected with telecommunication devices needs or nondestructive microwaves apparatus to control goods and people [19], cholesteric lasers [20,21], manufacturing tunable metamaterial [22][23][24][25]. Different devices such as tunable spatial modulators for light and laser beam steering and for holography [26][27][28][29][30][31][32][33], switchable phase shifters [34][35][36], various types of tunable filters which select or remove bands [37][38][39][40], tunable capacitors [41], antennas [42], lenses [43,44] were manufactured, and others such as photonic fiber [45] (see also, for more information, reviewed papers [46,47]).…”

“…For different electrooptic modes, different elastic constants are taken into account as decisively (k 33 for VAN or ECB, k 22 for IPS and K TN = k 11 + (k 33 − 2k 22 )/4 for TN). In devices addressed by one frequency, the decay time τ off , as being only a pure relaxation process, is longer than the rise time (τ off > τ on ).…”

High birefringence bistolane liquid crystals: synthesis and properties

“…scattering cholesteric 9 or scattering polymerdispersed liquid crystals, PDLC systems 10,11 ), devices working in the infrared range. [12][13][14] In recent years LCs have been found to be promising materials that can achieve high efficiency for microwave devices such as switchable phase shiers, [18][19][20] tunable lters, 21,22 metamaterials [23][24][25][26] and other applications. Therefore, there is a huge interest in studying high birefringence liquid crystal properties in the microwave region up to terahertz frequencies.…”

Terahertz and optical properties of nematic mixtures composed of liquid crystal isothiocyanates, fluorides and cyanides

“…The LC based devices which have demonstrated up to now include switchable phase shiers, 3 tunable lters, 4,5 a switchable THz Bragg structure, 6 and a tunable metamaterial. 7 Yet, in order to design efficient devices for this frequency region, the dielectric THz properties of the LCs have to be known precisely. 8 In particular, a high birefringence (Dn) of LCs is crucial in order to obtain a signicant phase shi (Df) according to…”