Free-standing porous silicon film with a tunable microcavity containing nematic liquid crystal

Free-standing multilayer porous silicon (PS) film containing half-wave microcavity is installed into a planar glass cell and infiltrated with a nematic liquid crystal (LC) mixture E7. Here we present the results of theoretical and experimental research of the LC orientational properties and spectral characteristics of the microcavity under variable temperature and electric field applied. The reversible thermal tuning of the resonant wavelength in the range of 13 nm is demonstrated. Spectra of the microcavity with the LC in the nematic phase were simulated using the Frank free energy approach assuming the LC molecular configuration being escaped radial (ER). Our model predicts electrical tuning of the microcavity. Probable tuning range varies from 8.5 nm up to 16 nm for weak and strong surface anchoring conditions in silicon pores, respectively.