Research direction: Electro-optical performance research
Experimental equipment: chemicals, arbitrary function generator, SLA-HVP-218 High Voltage Power Amplifier, precision impedance analyzer, etc.
Experimental purpose: The blue phase (BP) has attracted extensive attention due to its unique three-dimensional self-assembled structure and excellent electro-optic properties and has broad application prospects in the field of fast optical modulators or tunable photonic crystals.
Experiment procedure:
(1) Synthesis and characterization of dual-frequency liquid crystals;
The crude product synthesized was purified by silica gel chromatography, the eluent was dichloromethane, and the final product was obtained as a white powder after drying.
(2) Preparation of liquid crystal box;
Using a polyethylene terephthalate (PET) film as a spacer for a liquid crystal cell does not require the use of a surface alignment layer. LC in the isotropic state is filled into the liquid crystal cell through capillary action, and the transmittance of the tissue result is observed by applying electric
fields of different frequencies.
(3) The generators of electric fields with different frequencies are arbitrary function generators and power amplifier (SLA-HVP-218).
The dielectric constant and frequency response of liquid crystals were measured by a precision impedance analyzer, and the parallel dielectric constant and vertical dielectric constant were measured with vertically oriented and parallel oriented liquid crystal cells, respectively.
Test Results:
(1) Phase behavior of dual-frequency liquid crystal:
Figure 1 DSC curve of DFLC
Figure 2 Polarized pictures during heating up
(2) Frequency response of dual frequency blue phase liquid crystal:
Polarized photos of DF-BPLC under different electric fields (no electric field/50 Hz/50 kHz): cholesteric phase (a), blue phase (b), reentrant cholesteric phase (c) and temperature domain (d).
The effectiveness of SLA-HVP-218 High Voltage Power Amplifier in this experiment: amplify the signal to form electric fields of different frequencies, and observe the transmittance of the tissue results.
