Low-frequency vibrational modes of biological molecules consist of intramolecular modes, which are dependent on the molecule as a whole, as well as intermolecular modes, which arise from hydrogen-bonding interactions and van der Waals forces. Vibrational modes thus contain important information about conformation dynamics of biological molecules, and can also be used for identification purposes...

Integrated optical switches using mechano-optical sensing are gaining more attention in many fields due to their fast switching speed, large bandwidth and compact devices. In this paper, a micromachined electrostatically actuated metal plate to sense the evanescent field above the waveguide is presented. The feasibility of MEMS based light weight mechanical plates to achieve fast switching is e...

We demonstrate the focusing of a free-space THz beam emerging from a leaky parallel-plate waveguide (PPWG). Focusing is accomplished by grading the launch angle of the leaky wave using a PPWG with gradient plate separation. Inside the PPWG, the phase velocity of the guided TE1 mode exceeds the vacuum light speed, allowing the wave to leak into free space from a slit cut along the top plate. Sin...

Two diffraction problems involving cavities formed by a semi-infinite parallel-plate waveguide and by a finite parallelplate waveguide are rigorously analyzed for the plane wave incidence using the Wiener–Hopf technique. It is shown that the solution for the semi-infinite case is valid for arbitrary cavity dimensions, whereas the solution for the finite case is valid for the cavity depth large ...

For a good THz waveguide, both low propagating loss and small mode width are usually very important. However, the high ohmic loss of metals and the high absorption loss of dielectric materials result in that it still remains a challenge to obtain the two capabilities at the same time. In this paper, planar dielectric-gap-metal (DGM) waveguides are presented to guide THz wave. According to the d...

This article presents the exact closed-form solution for a new planar lens, hereinafter referred to as reflecting Luneburg lens (RLL). The proposed structure consists of two stacked parallel-plate waveguides circular shape. rays generated by point source located at periphery bottom waveguide propagate along curvilinear paths, whose trajectories result from variable refractive index profile with...