Simultaneous emission of orthogonal handedness in circular polarization from a single luminophore

The direct emission of circularly polarized (CP) light improves the efficiency of an organic light-emitting diode and characterizes the secondary structure of proteins. In most cases, CP light is generated from a luminescent layer containing chiral characteristics, thereby generating only one kind of CP light in an entire device. Here, we propose direct CP light emissions using a twisted achiral conjugate polymer without any chiral dopant as an emitting layer (EML). The twisted structure is induced in the mesogenic conjugate polymer due to its elasticity by applying different alignment directions to its upper and lower interfaces. Furthermore, we demonstrate the simultaneous emission of orthogonal CP light in a single luminescent device by patterning different alignment directions on the surfaces of the EML. The light source with multipolarization including the orthogonal CP states is applicable to many applications in biosensors and optical devices. Simultaneous right and left circular polarization from single device Both right- and left-handed circularly polarized light were generated from a single device, paving the way for novel applications in biosensors and organic LEDs. Chang-Jae Yu of Hanyang University in Korea and colleagues fabricated the device by using the liquid crystal phase of a polymer, called F8BT, which is commonly used in organic light-emitting diodes. They controlled the alignment of the molecules inside the polymer by rubbing its upper and lower surfaces in specific directions. The rubbing caused the molecules inside the polymer to align and twist. Light passing through the polymer simultaneously emerges as right- and left-handed circularly moving electromagnetic waves. The study demonstrates the feasibility of a light source with multiple polarizations, which could have applications in a variety of optical devices.