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Ever since Pendry's paper on perfect lens the idea of near field subwavelength imaging has been a driving force in the rapid development of the field of metamaterials as the search for suitable structures capable of near field imaging continues. A large variety of physical mechanisms were suggested to be responsible for near field imaging, ranging from excitation of surface plasmon-polariton resonances...
Negative phase velocity metamaterials are engineered media that are currently enjoying a surge of interest due to their interesting properties and potential applications, such as cloaking to make things invisible. The literature is alive with papers devoted to the design of suitable metamaterials and there is a particular desire to create photonic applications that will operate at THz frequencies...
A metamaterial composed of electromagnetically active cells with two parallel wires of sub-wavelength size can be fabricated by means of patterning techniques used in microelectronics. Intensity transmittance of layered metamaterial is assessed as a function of fill factor, that is a ratio of wire to layer surfaces, that in simulations changes from 6 to 20%. Negative refractive index reaching as low...
We show that using AlGaAs semiconductor as nonlinear material in a specific configuration of one dimensional periodic structure, we may actively induce important changes in the reflectivity of an optical beam. We show that a control beam at second harmonic frequency (0.77 mum) optically induces chances in the reflection coefficient of a signal at the fundamental frequency (1.55 mum), via the intrinsically...
The optical properties of photonic crystals can be altered most rapidly if a refractive index is altered using ultrashort optical pulses. I review several experiments in which we have used the Kerr effect or the Drude effect to switch optical properties of 2-D silicon photonic or GaAs photonic crystals on a picosecond or subpicosecond time scale. Tuning of the optical properties of a photonic crystal...
A spectrally resolving scanning near-field optical microscope (SNOM) has been developed in order to study the field distribution of the fundamental mode guided by a photonic crystal fiber. Moreover, through this near-field based technique effective area measurements have been realized
A grating was defined in a silicon nitride waveguide, using a combination of both conventional lithography and laser interference lithography. The structure was optically characterized in the 1520-1560 nm wavelength range by combining transmission measurements with the analysis of local out-of-plane scattered light, using a high-resolution infrared camera. From the measured power enhancement of the...
Photonic crystal waveguides have evolved from an academic curiosity to an area where practical applications are beginning to appear feasible. Waveguides consisting of a single line of missing holes ("W1") have become the benchmark to assess fabrication quality, and losses of order 10 dB/cm and below are now possible. We discuss fabrication aspects of such waveguides, made both by e-beam...
We report on transmission, field mapping, and spectral dependence of the group index in the slow light regime, obtained by numerical modelling. The influence of a finite number of lattice periods on the observed properties is pointed out
One of the exciting features of photonic crystals is that light may travel at very low group velocities at specific optical frequencies. In photonic crystal waveguides, such low group velocities are also possible. We have studied the propagation of femtosecond pulses in these waveguides, with a phase-sensitive and time-resolved near-field microscope. With this microscope, we visualized the pulses...
We show that the diffraction of electromagnetic radiation can disappear in propagation through materials with periodically in space modulated refraction index, i.e. through photonic crystals. We generalize this effect to propagation of light pulses in photonic crystals in the vicinity of the zero-diffraction point. We show that Gaussian pulses spread weakly in space and time during the propagation...
A rod-connected diamond structure is known to exhibit the largest full photonic bandgap. However, it's seemingly intricate structure turned off researcher's motivation for fabrication. In this paper, we propose a novel fabrication technology for optical rod-connected diamond photonic crystals by uniting angled dry etching method with micromanipulation. Although, diamond structures have been found...
We recently fabricated chalcogenide photonic crystal slabs (PCSs) using focused ion beam milling. We demonstrated over 98% coupling efficiency to a two-dimensional photonic crystal waveguide in a chalcogenide membrane using evanescent coupling via a tapered optical fibre nanowire. The presentation will discuss the design, fabrication and characterization of chalcogenide-based PCSs and preliminary...
Chalcogenide glasses are based on sulfur, selenium, tellurium and the addition of other elements such as arsenic, germanium, antimony, gallium, etc. These glasses combine high non linear properties with large infrared transmission from 0.5-1 mum to 12-18 mum depending on the composition. This work presents recent studies, concerning non linear optical properties of chalcogenide glasses and the elaboration...
A methodology for the design of functional integrated optical components is presented. Based on existing fabrication techniques, small structures whose optical signal processing functionality is achieved by interaction of optical scattering from many small sites, are designed. Parallel Genetic Algorithm optimization of a multiple scattering model is used to produce desirable system elements tailored...
We have studied how coupling together a 2 dimensional photonic crystal (2D PC), made in a SOI wafer, and a Bragg mirror could modify the light properties of the light emitted by the 2D PC. By finely tuning the distance separating the Bragg mirror and the 2D PC with a piezo-electric set-up, we have recorded a modulation of the extracted intensity as well as of the quality factor of the structure (Q)...
We will present recent progress in several devices based on silicon-on-insulator nanophotonics using deep-UV lithography. We will report on high efficiency grating couplers, ultra-compact arrayed waveguide gratings and ring-resonator based biosensors
This paper presents the development of a microspectrometer and a surface plasmon waveguide sensor on a silicon platform derived from the expertise acquired in designing optical telecommunication components
This paper reports on our recent advances in ultra-fast optical communications relying on ultra-short pulses densely stacked in ultra-high bit rate serial data signals at a single wavelength. The paper describes details in solutions for the network functionalities of wavelength conversion and clock recovery at bit rates up to 320 Gb/s
Multimode interference (MMI) structures have found wide application as low-order couplers, splitters, combiners, switches and multiplexers. Recent advances in MMI devices have led to ultra-short MMI couplers, segmented MMI structures and cascaded MMI switches. This paper reviews the modeling techniques applicable to MMI structures. The paper covers analytical, semi-analytical and numerical approaches...
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