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Slow light in tapered slot photonic crystal waveguide
Jun Wu,YanPing Li,ChuanChuan Yang,Chao Peng,ZiYu Wang
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0192-5
Abstract: A slotted single-mode photonic crystal waveguide with a linear tapered slot is presented to realize slow light, whose dispersion curve is shifted by changing the slot width. When the slot width is reduced, the band curve shifts in the tapered structure, and the group velocity of light approach zero at the cut-off frequency. Therefore, different frequency components of the guided light are slowed down even localized along the propagation direction inside a tapered slot photonic crystal waveguide. Furthermore, this structure can confine slow light-wave in a narrow slot waveguide, which may effectively enhance the interaction between slow light and the low-index wave-guiding materials filled in the slot. In addition, this tapered slot structure can be used to compensate group velocity dispersion of slow light by modifying the structure, thus opening the opportunity for ultra-wide bandwidth slow light.
Slow light with electromagnetically induced transparency in cylindrical waveguide  [PDF]
Agus Muhamad Hatta,Ali A. Kamli,Ola A. Al-Hagan,Sergey A. Moiseev
Physics , 2014,
Abstract: Slow light with electromagnetically induced transparency (EIT) in the core of cylindrical waveguide (CW) for an optical fiber system containing three-level atoms is investigated. The CW modes are treated in the weakly guiding approximation which renders the analysis into manageable form. The transparency window and permittivity profile of the waveguide due to the strong pump field in the EIT scheme is calculated. For a specific permittivity profile of the waveguide due to EIT, the propagation constant of the weak signal field and spatial shape of fundamental guided mode are calculated by solving the vector wave equation using the finite difference method. It is found that the transparency window and slow light field can be controlled via the CW parameters. The reduced group velocity of slow light in this configuration is useful for many technological applications such as optical memories, effective control of single photon fields, optical buffer and delay line.
Slow Light in a Bragg Waveguide  [PDF]
G. G. Kozlov,V. S. Zapasskii,V. V. Ovsyankin
Physics , 2008,
Abstract: One-dimensional defect photonic crystal (Bragg waveguide) is studied from the viewpoint of the slow light problem. The calculations are presented showing that in the TiO$_2$/SiO$_2$-based Bragg waveguide one can obtain the group index of $\sim$ 1000 and spatial decay length of $\sim$ 3 mm for a nanosecond-scale pulse. Distortion of the pulse due to the group index dispersion proves to be acceptable for the relative pulse delay not exceeding 10. We also analyze propagation of the light pulse in the Bragg waveguide with a quantum well inside and provide arguments showing possibility of reaching the group index of $\sim$ 10000. To the best of our knowledge, analysis of pulse propagation in a Bragg waveguide in connection with the slow light problem has not been performed so far. We will still much appreciate any information about such studies, if any.
To the possibility of the "slow light" in the waveguides  [PDF]
G. G. Kozlov
Physics , 2005,
Abstract: The atoms moving within the waveguide with a critical frequency higher than the resonant frequency of atoms are suggested for obtaining the "slow light". Due to the absence of the resonant mode in the guide the atoms conserves excitation and coherence. The speed of this mixed excitation (electromagnetic field + moving atom) can be very low or even zero. The atoms moving within the waveguide with a critical frequency higher than the resonant frequency of atoms are suggested for obtaining the "slow light". Due to the absence of the resonant mode in the guide the atoms conserves excitation and coherence. The speed of this mixed excitation (electromagnetic field + moving atom) can be very low or even zero.
Mode Coupling in a Tapered Slow Light Waveguide  [PDF]
S. He,Y. He,Y. Jin,J. He
Physics , 2010,
Abstract: Metamaterials with simultaneous negative permittivity and negative permeability (also called left-handed materials) open new avenues to achieving unprecedented physical properties and functionality unattainable with naturally occurring materials. It has been predicted that a metamaterial slab waveguide can slow down light significantly (even to zero velocity) as the thickness of the core layer approaches a critical thickness. Here we show that coupling between the forward and backward modes becomes significant near the critical thickness due to the good matching of the wavevectors and modal profiles of the two modes. Physical explanation and impact of this coupling are given.
The Sagnac effect in Coupled-Resonator Slow-Light Waveguide Structures  [PDF]
Jacob Scheuer
Physics , 2005, DOI: 10.1103/PhysRevLett.96.053901
Abstract: We study the effect of rotation on the propagation of electromagnetic waves in slow-light waveguide structures consisting of coupled micro-ring resonators. We show that such configurations exhibit new a type of the Sagnac effect which can be used for the realization of highly-compact integrated rotation sensors and gyroscopes.
Lasing in localized modes of a slow light photonic crystal waveguide  [PDF]
Jin-Kyu Yang,Heeso Noh,Michael J. Rooks,Glenn S. Solomon,Frank Vollmer,Hui Cao
Physics , 2011, DOI: 10.1063/1.3600344
Abstract: We demonstrate lasing in GaAs photonic crystal waveguides with InAs quantum dots as gain medium. Structural disorder is present due to fabrication imperfection and causes multiple scat- tering of light and localization of light. Lasing modes with varying spatial extend are observed at random locations along the guide. Lasing frequencies are determined by the local structure and occur within a narrow frequency band which coincides with the slow light regime of the waveguide mode. The three-dimensional numerical simulation reveals that the main loss channel for lasing modes located away from the waveguide end is out-of-plane scattering by structural disorder.
Efficient light coupling into a photonic crystal waveguide with flatband slow mode  [PDF]
A. S?yn?tjoki,K. Vynck,M. Mulot,D. Cassagne,J. Ahopelto,H. Lipsanen
Physics , 2008, DOI: 10.1016/j.photonics.2008.03.001
Abstract: We design an efficient coupler to transmit light from a strip waveguide into the flatband slow mode of a photonic crystal waveguide with ring-shaped holes. The coupler is a section of a photonic crystal waveguide with a higher group velocity, obtained by different ring dimensions. We demonstrate coupling efficiency in excess of 95% over the 8 nm wavelength range where the photonic crystal waveguide exhibits a quasi constant group velocity vg = c/37. An analysis based on the small Fabry-P\'erot resonances in the simulated transmission spectra is introduced and used for studying the effect of the coupler length and for evaluating the coupling efficiency in different parts of the coupler. The mode conversion efficiency within the coupler is more than 99.7% over the wavelength range of interest. The parasitic reflectance in the coupler, which depends on the propagation constant mismatch between the slow mode and the coupler mode, is lower than 0.6% within this wavelength range.
Slow light with three-level atoms in metamaterial waveguides  [PDF]
Benjamin R. Lavoie,Patrick M. Leung,Barry C. Sanders
Physics , 2013, DOI: 10.1103/PhysRevA.88.023860
Abstract: Metamaterial is promising for enhancing the capability of plasmonic devices. We consider a cylindrical waveguide with three-level \Lambda\ atoms embedded in the dielectric core. By comparing metal cladding vs metamaterial cladding of a waveguide with \Lambda\ atoms in the core, we show that, for a fixed amount of slowing of light due to electromagnetically induced transparency, the metamaterial cladding outperforms in terms of the inherent loss.
Self-organization of atoms along a nanophotonic waveguide  [PDF]
D. E. Chang,J. I. Cirac,H. J. Kimble
Physics , 2012, DOI: 10.1103/PhysRevLett.110.113606
Abstract: Atoms coupled to nanophotonic interfaces represent an exciting frontier for the investigation of quantum light-matter interactions. While most work has considered the interaction between statically positioned atoms and light, here we demonstrate that a wealth of phenomena can arise from the self-consistent interaction between atomic internal states, optical scattering, and atomic forces. We consider in detail the case of atoms coupled to a one-dimensional nanophotonic waveguide, and show that this interplay gives rise to self-organization of atomic positions along the waveguide, which can be probed experimentally through distinct characteristics of the reflection and transmission spectra.
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