Dielectric spectra of two pristine blue-phase liquid crystals and a polymer-stabilized counterpart were acquired at various temperatures in conjunction with simultaneous observations of their optical transmission spectra and birefringent textures. This figure shows transmission spectra and a POM image of the BPLC sample, BP I (87.8 degrees).
For details, see W. Lee et al. Opt. Mater. Express 4, 2392-2400 (2014).