For TM mode, the coupling efficiency can also obtain more than 50% and 35 nm 1 dB bandwidth.
When incident wavelength is 1550 nm, for TE mode, the coupling efficiency can achieve more than 50% with ∼30 nm 1 dB bandwidth.
As a function of initial beam power and the fiber mode design, the coupling efficiency plots are calculated and compared for different nonlinear mediums.
Many practical characteristics of the optical fiber, such as the mode-field diameter, the coupling efficiency between fibers, and the effective cross-section area, are determined by mode-field distribution.
Further, combination of blazing and dual interface grating structures were observed to be more accessible modes with a strong coupling efficiency which ultimately enhanced the light absorption.
Compared with spherical particles, hemispherical and cylindrical particles show much lower and broader scattering cross section, containing two surface plasmon resonance modes, and much higher coupling efficiency at longer wavelengths.
In [35], an SLM is used to calculate phase masks for each mode using a simulated annealing approach which aims to find the most efficient hologram capable of generating a mode with the highest power coupling efficiency based on the MMF profile.
The proposed USM belongs to the bolt-clamped type motor, and the PZT ceramics work with d33 mode, which has high electromechanical coupling efficiency and can improve the mechanical output characteristics.
In these peculiar disordered structures, a trade-off between the mode lifetime τ (defining the coupling efficiency from the vertical direction) and the absorption time τ a (the average time after which light is absorbed by the dielectric medium) is crucial to properly engineer the structure.
Moreover, coupling efficiency from fundamental mode of the SMF to specific higher-order mode of the FMF can be optimized by adjusting the number of the coiling period, which is beneficial for the design and fabrication of mode converter.
