Detecting the phase transition of blue phase liquid crystals by skewness-inversion imaging

Abstract

Short-pitch blue phase liquid crystals appear colorless due to their pseudo-optical isotropy, and detecting their phase transitions can be difficult. Here, we show that a critical transition analysis based on the statistical properties of light scattering signals enables visualization of colorless phase transitions in blue phases. We find that the skewness, or the third statistical moment of the intensity distribution is particularly effective in analyzing phase transitions, since its sign becomes inverted at the transition. The method can be adapted to a wide variety of material systems and microscopy techniques, providing a powerful tool for studying complex critical transition phenomena.