Research / 2019 / Article / Fig 5

Research Article

Electrically Programmable Terahertz Diatomic Metamolecules for Chiral Optical Control

Figure 5

Electrically programmable chiral platform. (a) Schematic diagram of the electrically programmable chiral platform. The neighboring two microhelices in each metamolecule are electrically isolated and separately connected to input channel 1 (C1) and channel 2 (C2). Encoding sequences 11], 01], 10], and 00] enable the four chiral conformations: a, L, D, and r, respectively. The diagram schematically shows D- conformation with 10] input that gives rise to intrinsic chirality with a nontrivial CD response. (b) Summary of the logical operation for the programmable chirality platform in terms of intrinsic optical chirality output following an “exclusive OR (XOR)” gate. A nontrivial CD output is defined as “1” and a trivial CD output is defined as “0”. (c, d) Measured output polarization states described by ellipticity and rotation angle of polarization (AOP) with y-polarized incidence at four chiral conformations enabled by the respective encoding sequences. (e) Visualized output polarization states in polar coordinates that are measured at three specific frequencies with 01] and 10] inputs. The output polarization plane is rotated by large angles at 0.4 and 0.7 THz, and polarization state is modulated to elliptical states with opposite handedness at 0.63 THz. Dots are measured angle-resolved transmission intensity by rotating an analyzer.