Equilibrium mode distribution

About: Equilibrium mode distribution is a research topic. Over the lifetime, 928 publications have been published within this topic receiving 14939 citations.

Design of mode converters for generating the TE11 mode from TM01 vircator at 4GHz

Abstract: This work reports on measurements and calculations (coupled mode equations) on the conversion of transverse magnetic TM01 vircator mode at 4 GHz to the linearly polarized TE11 mode by means of mode converter systems using a circular waveguide with curvature. The mode converter is composed of a 38.78° bend with 39.07 cm curvature and a 50.78° inverse bend with 25.24 cm curvature in 9 cm internal diameter (ID) circular waveguide. The efficiency of conversion from TM01 to TE11 at 4 GHz exceeds 99%, and the overall efficiency from TM01 to TE11 exceeds 90% over a calculated range of 3.72–4.8 GHz.

Adiabatically tapered microstructured mode converter for selective excitation of the fundamental mode in a few mode fiber.

Abstract: We propose a new technique to selectively excite the fundamental mode in a few mode fiber (FMF). This method of excitation is made from a single mode fiber (SMF) which is inserted facing the FMF into an air-silica microstructured cane before the assembly is adiabatically tapered. We study theoretically and numerically this method by calculating the effective indices of the propagated modes, their amplitudes along the taper and the adiabaticity criteria, showing the ability to achieve an excellent selective excitation of the fundamental mode in the FMF with negligible loss. We experimentally demonstrate that the proposed solution provides a successful mode conversion and allows an almost excellent fundamental mode excitation in the FMF (representing 99.8% of the total power).

Development of mode converters for 28 GHz electron cyclotron heating system

Abstract: Small circular waveguide mode converters used in the 28 GHz, 200 kW ECH system for the Hitachi tokamak HT-1 have been developed. In order to convert from the TE02 to the TE11 mode, TE0202-to-TE01 and TE01-to-TE11 mode converters are used. Both converters use periodic waveguide wall perturbations, the case of the former, circularly symmetric perturbations, and in the case of the latter, curvature perturbations. The lengths of the mode converters were successfully shortened with high mode conversion efficiencies by decreasing the number of periods and then optimizing the periods using quite a small diameter for the converters. The 30ϕ TE02-to-TE01 mode converter is 103 · 34 mm long and its mode conversion efficiency measured by a scalar network analyser is 96% at 28GHz. The TE01-to-TE11 mode converter is 427 · 38 mm long and has an efficiency of 79%, which is 10% lower than the design value. This discrepancy resulted mainly from mode conversion from the TE11 to the TE12 mode, caused by the smaller number of...

Communication system having low dispersion glass optical waveguide

Abstract: An optical waveguide for use in an optical communication system employing a broad spectral source. Mode coupling is present in the propagation of optical signals in the waveguide, and the parameters of the waveguide are such that pulse dispersion produced by the finite spectral width of the source is minimized by utilizing the mode coupling to substantially cause cancellation of dispersion which is linear with respect to waveguide length and which is caused by the mode independent material dispersion and by the mode dependent waveguide dispersion.