Self-alignment of liquid crystals in three-dimensional photonic crystals

Abstract

We report on the observation of self-alignment of nematic liquid crystals into colloidal photonic crystals, over distances much larger than the typical size of the voids between the spheres. We observe that the infiltrated structure possesses a unique optical axis that is determined by an intrinsic structural anisotropy of photonic crystal opals. We develop a simple model to describe this self-alignment based on the connectivity of the pores. The resulting structure constitutes a polarization dependent photonic crystal that can be controlled electrically.

Orientation-dependent spontaneous emission rates of a two-level quantum emitter in any nanophotonic environment

“…A class of quantum emitters with a single transition dipole moment are fluorescent molecules, such as laser dyes [4]. For such emitters, emission-rate surfaces can be observed if their orientation is controlled, e.g., by attaching them to liquid crystal molecules that are oriented in external fields [31]. If one can tune the orientation of an emitter, this opens a novel opportunity to "switch" spontaneous emission from inhibited to enhanced and vice versa.…”

Ultrafast optical switching of photonic crystals

“…We propose that the mismatch may be caused by a slightly rhombohedral unit cell, which will result in a modified band structure. A distortion of the fcc structure is consistent with other reports that vertical controlled drying yields opal structures that deviate from fcc [37].…”

“…An important issue in the vertical controlled drying method [36], which is used to fabricate the opaline templates is the lack of control over the crystal symmetry [37]. Recent results have demonstrated that some control over the lattice symmetry and orientation can be obtained through the use of patterned templates [38][39][40][41], see Fig.…”

Ultrafast optical switching of photonic crystals

“…An important issue in the vertical controlled drying method [36], which is used to fabricate the opaline templates is the lack of control over the crystal symmetry [37]. Recent results have demonstrated that some control over the lattice symmetry and orientation can be obtained through the use of patterned templates [38][39][40][41], see Fig.…”