Delay-time measurements in narrowed waveguides as a test of tunneling

Abstract

Delay-time investigation of electromagnetic waves through homogeneous medium and photonic crystal left-handed materials Appl. Phys. Lett. 85, 1125 (2004); 10.1063/1.1781742 Delay-time and aging effects on contrast and sensitivity of hydrogen silsesquioxane

Experimental and Theoretical Studies of a Broadband Superluminality in Fabry-Perot Interferometer

“…3(c) is obtained at the case of h/b = 0.09, in which the transmission approximately equals 3.2%. This undersized waveguide system is not equivalent to a single opaque barrier [9][10][11][12][13][14][15][16][17], because the signal of fundamental mode does propagate within the middle section, and thus the transmission in superluminal regime is significantly higher than that of single-barrier system.…”

“…Notably, the discontinuities of the undersized/oversized waveguide will excite high-order evanescent modes in addition to the fundamental mode, which is called the modal effect. The importance of the modal effect had long been noted [11][12][13][27][28][29][30][31], but its effect and extended application on the superluminality has never been studied.…”

“…Such phenomenon called superluminality is generally attributed to steep anomalous dispersion [1][2][3][4][5][6][7][8] and tunneling effect [9][10][11][12][13][14][15][16][17], which have been experimentally demonstrated in the electromagneticallyinduced-absorption [1][2][3][4][5]/ring-resonator [6][7][8] optical systems and the photonic/waveguide [9][10][11][12][13][14][15][16][17] systems, respectively. However, the systems employing the anomalous dispersion usually operate near the steep absorption line, which leads to a narrow superluminal frequency range as well as low transmission (for passive systems), while the systems associated with the tunneling mechanism also suffer from extremely low transmission [16][17][18][19][20][21][22][23][24][25][26].…”

“…A potential barrier/well can be modeled by either inserting a dielectric material into a uniform waveguide [14-17, 20, 21] or using an undersized/oversized waveguide changed in width [11][12][13]. Notably, the discontinuities of the undersized/oversized waveguide will excite high-order evanescent modes in addition to the fundamental mode, which is called the modal effect.…”

“…On the basis of the superluminal studies in waveguide system [11][12][13][14], the propagation of an electromagnetic wave in a waveguide is considered to be an ideal resemblance to a time-independent quantum system [11] due to the similarity between cutoff frequency and quantum potential. A potential barrier/well can be modeled by either inserting a dielectric material into a uniform waveguide [14-17, 20, 21] or using an undersized/oversized waveguide changed in width [11][12][13].…”