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It is widely accepted that quadratic nonlinear processes, such as parametric generation or amplification, require the use of materials with a high degree of ordering. In some occasions, such ordering is found at a nanoscale, and in other cases, the order is at a micron scale. When such ordering is not intrinsic to the material, one may introduce a periodical distribution within the nonlinear material...
Quadratic optical nonlinearities offer several attractive features for the implementation of ultra-fast, low-noise and transparent telecom devices. Technological progress has dramatically increased their efficiency, driving a steady move towards practical applications. In this talk we shall discuss the use of cascaded quadratic interactions in LiNbO3 integrated devices for pulse diagnostics, format...
We observe the optical methods of analog-to-digital conversion, matrix multiplication, pick-up of the information about the temperature of physical objects and other operations, which based on the use of controlled waveguide ring microresonators. The structural diagrams of the devices realizing these operations are presented. The results of calculation, which permit to optimize the structure and basic...
This paper presents the analytic results of comparison of mode transformation in 2D time-varying photonic structures on examples of plane waveguide and circular whispering gallery mode (WGM) resonator. The situation is that a natural mode propagates inside the structure at the moment when the refractive index changes abruptly in time inside it. The basic interest is to gain insight into details of...
We have developed solid-state single-photon sources based on single InAs quantum dots emitting at 1300 nm. We report antibunching experiment and electroluminescence measurements, showing that our system can be used as an efficient single photon source under optical and electrical pumping
Chip gain of 26 dB upon amplification of 1.3 picosecond pulses at frequencies up to 80 GHz is demonstrated for temperature stable QD-SOAs. Pulse broadening in the below 200 fs range is observed. The results agree with our predictions on decoupling of gain and index of refraction in Q-based amplifiers. Modelling of wavefunctions in stacked QD-layers based on 8-band k.p-theory indicates the potential...
InGaAs quantum dots (QDs) and nanowires have been grown on GaAs by metal-organic chemical vapour deposition on GaAs (100) and (111)B substrates, respectively. InGaAs QD lasers were fabricated and characterised. Results show ground-state lasing at about 1150 nm in devices with lengths greater than 2.5 mm. We also observed a strong influence of nanowire density on nanowire height specific to nanowires...
High-power semiconductor lasers are widely used for pumping erbium-doped and Raman amplifiers as well as for a number of non-communications applications. The record performance so far has been achieved using broadened symmetric waveguide design, which however may have significant limitations at very high current densities. We assess these limitations and discuss the advantages of our recently proposed...
Ballistic light propagation in the heterogeneous photonic crystals based on the thin triple-film opal have been studied in the wavelength range of low order photonic bandgaps. Since the scattered light experiences the diffraction attenuation, the spectra and the angle diagrams of the transmitted and forward scattered light have been used to identify the effect of heterostructuring
The paper refers to the experimentally observed emission of quantum dot lasers from higher excited states and to the closely related experiments on the emission of quantum dot samples from higher excited states and the effects of up-conversion of electronic level occupation. The attention is paid to certain experiments in which the dependence of the up-conversion effect on the intensity of the optical...
Advantages of photo-fabrication as a novel technology for materials processing in application to writing 3D microstructures in glasses are discussed. Theoretical model of focused femtosecond pulse energy deposition into a glass sample and subsequent heat diffusion is presented
ZnSe-GaAs heterostructures are heterovalent semiconductor heterostructures which are almost lattice-matched, and appear in most recently demonstrated blue and blue-green lasers. The large valence band offset present in this heterojunction also hinders holes injection from the III-V substrate into the II-VI active layer. Using photocurrent (PC) measurements we have investigated Schottky contacts formed...
We report on recent results by surface periodic poling on lithium niobate and lithium tantalate. Such approach allows periodic inversion of the second order susceptibility with nanoscale features using insulating masks. We achieved a world-best 200 nm feature size, as well as good compatibility with alpha-phase proton exchanged channel waveguides in lithium niobate. Preliminary results of surface...
Mechanically interlocked molecules such as rotaxanes are fascinating for their potential in molecular-scale devices. Rotaxane, stimuli-responsive "molecular shuttles" are molecules where a macrocyclic "bead" is locked onto a linear "thread" by bulky "stoppers". Large amplitude motion of the macrocycle can be induced by external stimuli (e.g. light, electrons,...
In the present report principal optical properties, of semiconducting large-sized nanocrystalline (LSNC) (with thickness within 10-50 nm) are presented. A quantitative parameter for description of the LSNC state is introduced. Influence of the surrounding polymer matrices on the properties of the LSNC is shown. Role of the surrounding polymer matrix background in the manifestation of the optoelectronic...
Functionalized azo-carbazole compounds, when exposed to two interfering polarized coherent laser beams, show efficient mixed amplitude and phase recording ability, frequently accompanied with surface relief grating formation. The aim of the present work is to study the dynamics of grating recording in azo-carbazole compounds using 30 ps train of pulses (532 nm, 1.2 mJ). The build-up of diffraction...
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