This PDF file contains the front matter associated with SPIE Proceedings Volume 6904, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

A competent method for slowing and completely stopping light, based on wave propagation along an adiabatically tapered negative-refractive-index metamaterial heterostructure, is presented. It is analytically shown that, in principle, this method simultaneously allows for broad bandwidth operation (since it does not rely on group index resonances), large delay-bandwidth products (since a wave packet can be completely stopped and buffered indefinitely) and high, almost 100%, in/out-coupling efficiencies. Moreover, by nature, the presented scheme invokes solid-state materials and, as such, is not subject to low-temperature or atomic coherence limitations. A wave analysis, which demonstrates the halting of a monochromatic field component travelling along the heterostructure, is followed by a corresponding ray analysis that illustrates the trapping of the associated light-ray and the formation of a double light-ray cone ('optical clepsydra'). This method for trapping photons conceivably opens the way to a multitude of hybrid, optoelectronic devices to be used in 'quantum information' processing, communication networks and signal processors, and may herald a new realm of combined metamaterials and slow light research.

We discuss how subwavelength-diameter silica-fibers, "optical nanofibers", can open new perspectives for manipulating atoms and photons. We explore atom/photon interaction around a nanofiber using laser-cooled Cs-atoms. We show that single atoms on a nanofiber can work as an optically dense medium which may give a novel work medium for slow light through an optical fiber. Basic characteristics for single atoms on a nanofiber; spontaneous emission, single-atom trapping, photoabsorption, and quantum interference, are discussed.

Since the proposition of D.D. Smith et al. [Phys. Rev. A 69 pp. 063804, 2004], the experimental demonstration of coupled resonator induced transparency has been made using passive fiber or whispering-gallery-mode microspheres. These demonstrations show that it is possible to integrate delay lines using high quality resonators. The maximal group delay that it can be introduced depends mainly on the relative value of the intrinsic losses with respect to the value of the coupling between the resonators. In this paper we experimentally show that the limit given by the intrinsic losses of the resonators can be circumvented by using active resonators. Our experimental setup consists in two coupled Er³⁺ doped fiber resonators. Each resonator can be pumped independently. Consequently, the values of the residual losses in the two resonators can also be modified independently. We then show that the transparency of the coupled resonators can be maximized using the right pumping rate in each resonator. By inserting this device into one arm of a fiber Mach-Zehnder interferometer we are able to optically measure the phase shift produced by the coupled resonators as a function of the optical frequency. The group delay can be deduced from this information.

Optical tunable delay lines have many applications for high-performance optical switching and signal processing. Slowlight has emerged as an enabling technology for achieving continuously tunable optical delays. The reconfigurable delay opens up a whole new field of nonlinear signal processing using slow light. In this paper, we review recent advances in slow-light-based optical signal processing, with a focus on the data fidelity after traversing the slow light elements. The concept of slow-light-induced data-pattern dependence is introduced and is shown to be the main signal degrading effect. We then propose and experimentally demonstrate phase-preserving slow light by delaying 10-Gb/s differential-phaseshift- keying (DPSK) signals with reduced DPSK data pattern dependence. Spectrally-efficient slow light using advanced multi-level phase-modulated format is further described. With this technique, doubled or even tripled bit-rate signals can be transmitted through a bandwidth limited slow light element. We finally show several novel slow-light-based signal processing modules. Unique features such as multi-channel operation and variable bit-rate capability are highlighted.

We demonstrate interesting and previously unforeseen properties of a pair of gap solitons in a resonant photonic crystal which can be predicted and explained in a physically transparent form using both analytical and numerical methods. The most important result is the fact that we are able to show that the oscillating gap soliton created by the presence of an inversion inside the crystal can be manipulated by means of a proper choice of bit rate, phase and amplitude modulation. Using this approach, we were able to obtain qualitatively different regimes of the resonant photonic crystal operation. A noticeable observation is that both the delay time and amplitude difference must exceed a certain level to ensure effective control over soliton dynamics. The modification of the defect that accomplishes the soliton trapping can make the dynamics of N soliton trains in the resonant photonic crystal with defects even more interesting and is a subject of the future work.

We present a preliminary experimental study of the dependence on optical depth of slow and stored light pulses in Rb vapor. In particular, we characterize the efficiency of slow and stored light as a function of Rb density; pulse duration, delay and storage time; and control field intensity. Experimental results are in good qualitative agreement with theoretical calculations based on a simplified three-level model at moderate densities.

Harnessing the unique optical quantum interference effects associated with electromagnetically induced transparency (EIT) on a chip promises new opportunities for linear and nonlinear optical devices. Here, we review the status of integrated atomic spectroscopy chips that could replace conventional rubidium spectroscopy cells. Both linear and nonlinear absorption spectroscopy with excellent performance are demonstrated on a chip using a self-contained Rb reservoir and exhibiting a footprint of only 1.5cm x 1cm. In addition, quantum interference effects including V-scheme and Λ-scheme EIT are observed in miniaturized rubidium glass cells whose fabrication is compatible with on-chip integration.

Using quantum optical techniques to manipulate nanoscale surface plasmons guided along conducting nanostructures can enable an unprecedented level of control over the interaction between light and matter. This field of "quantum plasmonics" enables many applications such as single-photon sources and single-photon transistors and opens up the possibility of creating novel states of light. One potential limitation of plasmonics technology is associated with losses in the conductor, which limit the distance that the surface plasmon excitations can propagate. Here we discuss the potential for improvement by operating plasmonic devices at lower temperature. In particular, we analyze the temperature dependence of a major mechanism for propagation losses, involving absorption of surface plasmons via electron-phonon scattering in the conductor. We find that the ability to "freeze out" this loss mechanism depends highly on the frequency of the surface plasmon modes. In particular, losses at terahertz frequencies can be strongly suppressed, which potentially allows the techniques of quantum plasmonics to be extended to this new regime of operation.

This paper presents an experiment to realize both slow and fast light effects simultaneously using the Raman gain and pump depletion in an atomic vapor. Heterodyne phase measurement shows the opposite dispersion characteristics at pump and probe frequencies. Optical pulse propagations in the vapor medium also confirm the slow and fast light effects due to these dispersions. The method being experimentally simple, and allowing the use of intense pulses experiencing anomalous dispersion via the fast light, can be applied in rotation sensing and broadband detection schemes proposed recently.

We have recently reported atomic spectroscopy using on-chip rubidium vapor cells based on hollow core waveguides. To make the cells more robust and capable of multiple temperature cycles, we examined several techniques for Rb introduction and sealing. To date the most successful sealing technique has been pinching off the end of a short length of copper tubing. This technique not only hermetically seals the cells, but also allows them to be evacuated to a desired pressure. We have been able to evacuate glass prototype Rb vapor cells to a pressure as low as 80 mTorr and as high as 2 Torr and successfully observe the Rb optical absorption spectrum. Along with our testing of sealing techniques we have been observing the effects of different epoxies and inert gas atmospheres on the robustness of vapor cells. With optimal parameters we have successfully observed the Rb optical absorption spectrum through multiple temperature cycles. These new Rb introduction and sealing methods will be applied to on-chip cells containing integrated hollow waveguides which can be used for a number of different optical applications, such as electromagnetically induced transparency, single-photon nonlinearities, and slow light.

We study the lasing eigen-modes and dynamics of circular coupled laser array in a rotating framework for ultra-sensitive integrated optical rotation sensing applications. The dependence of the mode and frequency splitting on the array parameters is studied in details. The impact of variations of the resonance wavelength of the individual cavities and the inter-cavity coupling is studied and found to generate a "dead-zone" which limits the sensitivity of the sensor.

Reduced density matrix descriptions are developed for linear and non-linear electromagnetic interactions of moving atomic systems, taking into account applied magnetic fields as well as atomic collisions together with other environmental decoherence and relaxation processes. Applications of interest include electromagnetically induced transparency and related pump-probe optical phenomena in warm atomic vapors. Time-domain (equation-of-motion) and frequency-domain (resolvent-operator) formulations are developed in a unified manner. The standard Born (lowestorder perturbation-theory) and Markov (short-memory-time) approximations are systematically introduced within the framework of the general non-perturbative and non-Markovian formulations. A preliminary semiclassical treatment of the electromagnetic interaction is adopted. However, the need for a fully quantum mechanical approach is emphasized. Compact Liouville-space operator expressions are derived for the linear and the general (n'th order) non-linear macroscopic electromagnetic-response tensors occurring in a perturbation-theory treatment of the semiclassical electromagnetic interaction. These expressions can be evaluated for coherent initial atomic excitations and for the full tetradic-matrix form of the Liouville-space self-energy operator representing the environmental interactions in the Markov approximation. Collisional interactions between atoms can be treated in various approximations for the selfenergy operator, and the influence of Zeeman coherences on the macroscopic electromagnetic response can be investigated.

We propose a general approach to the design of directional couplers in photonic-crystals operating in the slowlight regime. We predict, based on a general symmetry analysis, that robust switching of slow-light pulses is possible between antisymmetrically coupled photonic crystal waveguides. We demonstrate, through numerical Bloch mode frequency-domain and finite-difference time-domain (FDTD) simulations that, for all pulses with strongly reduced group velocities at the photonic band-gap edge, complete switching occurs at a fixed coupling length of just a few unit cells of the photonic crystal.

Surface plasmon polariton is a coupled electromagnetic wave and material (electron) density wave. This efficient coupling is the primary means of transforming light to a heavier particle which yields the desired "light slowing". The dispersion curve of surface plasmonic waves exhibits both wave slowing (phase velocity) and light slowing (group velocity). We detail the different avenues for light slowing and reversing (backward propagation) in a plasmonic structure based on a dielectric gap between two metal plates. Light slowing and almost stopping can be achieved as well as the more intriguing effect of backward propagation, accompanied by negative refraction. These effects in plasmonic structures can be used for nano virtual cavities (mirrorless cavities) for ultralow volume sensing as well as generating large local field enhancement.