In high plasma density and high magnetic field scenarios, both the lower and upper X-mode cut off frequencies are detected in the probing range.
Even when the fluid sound speed is slower than the elastic wave speeds of the solid, the higher-order modes are cut off in the long-wave limit and only one mode is permitted for each symmetry.
The theory developed applies below half the ring-frequency and when higher order fluid modes are cut off.
With the aid of the inner cladding formed by the central air holes, one polarization of the fundamental mode can be cut off at very short wavelengths and ultra-wideband SPSM propagation can be achieved.
The QTEM modes below the first mode cut-off frequency are shown in the spectrograms (Fig. 1).
For the single mode cut-off, y = 0 (i.e. β = ±k cl ), which is physically interpreted as the mode evanescently decaying into the cladding.
W-type three layered fiber structure is also analyzed in terms of modal guidance and location of the LP01 mode cut-off.
In order to achieve a net gain around 940 nm, requirements in fiber waveguide parameters for the LP01 mode cut-off and bending loss were theoretically investigated.
The tolerance of the LP01 mode cut-off wavelength and the accompanying bending loss are theoretically analyzed in terms of waveguide parameters.
The propagation of ELF-VLF waves in the EIWG is analyzed in term of quasi-transverse electric (QTE) and quasi-transverse magnetic (QTM) modes with the first mode cut-off frequency of about 1.8 kHz.
It can be seen from this equation that the toroidal frequency Ω TN corresponds to the mode resonance (k1 → ∞) while the poloidal frequency corresponds to the mode cut-off (k1 = 0).
