Slow Light Rainbow Trapping in a Uniformly Magnetized Gyromagnetic Photonic Crystal Waveguide

We present a hybrid gyromagnetic photonic crystal (GPC) waveguide composed of different GPC waveguide segments possessing various cylinder radii and waveguide widths but biased by a uniform external magnetic field. We demonstrate in frequency and time domains that based on the strong coupling of two counter-propagating topologically protected one-way edge states, the intriguing slow light rainbow trapping (SLRT) of electromagnetic (EM) waves can be achieved, that is, EM waves of different frequencies can be slowed down and trapped at different positions without cross talk and overlap. More importantly, due to the existence of one-way edge states, external EM waves can be non-reciprocally coupled to the SLRT waveguide channel, although the incident position of the EM wave is far away from the waveguide channel. Besides, the frequency range of the slow light states can also be easily regulated by tuning the intensity of an external magnetic field, which is very beneficial to solve the contradiction between slow light and broad bandwidth. Our results can be applied to the design of high-performance photonic devices, such as an optical buffer, optical switch, and optical filter.

Design and optimization of 1 × 2 N Y-branch optical splitters for telecommunication applications

This paper presents the design and optimization of 1 × 2 N Y-branch optical splitters for telecom applications. A waveguide channel profile, used in the splitter design, is based on a standard silica-on-silicon material platform except for the lengths of the used Y-branches, design parameters such as port pitch between the waveguides and simulation parameters for all splitters were considered fixed. For every Y-branch splitter, insertion loss, non-uniformity, and background crosstalk are calculated. According to the minimum insertion loss and minimum non-uniformity, the optimum length for each Y-branch is determined. Finally, the individual Y-branches are cascade joined to design various Y-branch optical splitters, from 1 × 2 to 1 × 64.

To the Question of the Independence of the Surface Electromagnetic Wave Frequency

Earth's the surface is often strongly inductive, consisting of a dielectric layer thickness endpoint, lying on an unlimited conductor basis. Electromagnetic wave, spreading along the surface, it appears captured dielectric layer, spreading it as in the waveguide channel. Waveguide theory it is known that the spread in the waveguide can only electromagnetic waves with a discrete set of frequencies. And experience shows that the captured waveguide channel electromagnetic waves can be any frequency. The article found that this behavior is due to the fact that electromagnetic waves in free space border - dielectric layer damped height in several wavelengths. Thus the thickness of the dielectric layer becomes more effectively, and this leads to a reduction of the minimum frequency of the waveguide. A discrete set of frequencies is blurred so that cover each other. Thus, a discrete set of frequencies becomes solid, and captured waveguide channel electromagnetic waves are independent of frequency.

Волноводная антенна с расширенным угловым диапазоном для дистанционного управления направлением волнового пучка

A new method for increasing the angular range of a waveguide antenna for remote steering of the wave-beam direction in thermonuclear-fusion experimental setups with plasma magnetic confinement is proposed. Characteristics for large beam inclination angles can be improved using the synthesized nonuniform waveguide profile. For small angles, the characteristics remain invariable, the waveguide profile differs only slightly from the regular shape, and can be fit to limited waveguide-channel sizes.