Heteroepitaxy of novel NLO materials for frequency conversion laser sources in mid- and longwave infrared with applications in defence and security (Conference Presentation)

2019 ◽  
Author(s):  
Vladimir Lubomirov Tassev ◽  
Shivashankar R. Vangala
Keyword(s):  
Frequency Conversion ◽  
Nlo Materials ◽  
Laser Sources

scholarly journals Thick Hydride Vapor Phase Heteroepitaxy: A Novel Approach to Growth of Nonlinear Optical Materials

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 393 ◽  
Author(s):  
Vladimir L. Tassev ◽  
Shivashankar R. Vangala
Keyword(s):  
Vapor Phase ◽  
Nonlinear Optical ◽  
Frequency Conversion ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Organic Chemical ◽  
Gradual Change ◽  
Lattice Match ◽  
Nlo Materials ◽  
Laser Sources

At the time when many nonlinear optical (NLO) materials for frequency conversion of laser sources in the mid and long-wave infrared have achieved their fundamental or technological limits, we propose heteroepitaxy as a solution to develop novel NLO materials. Heteroepitaxy, is the most applied method to combine two different materials—by growing one material on another. In this work we show that combining two binary materials in a ternary may significantly improve the NLO properties that are of great importance for the pursued applications. Plus, due to the closer lattice match to the related substrate, a ternary is always a more favorable heteroepitaxial case than the two completely different materials. We also discuss combining different growth methods—one close-to-equilibrium (e.g., hydride vapor phase epitaxy—HVPE) with one far-from-equilibrium (e.g., metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE)) growth processes—to explore new opportunities for the growth of novel heterostructures, including ternary layers with gradual change in composition. The combination of different materials by nature—organics with inorganics—in a hybrid quasi-phase matching (QPM) structure is another topic we briefly discuss, along with some innovative techniques for the fabrication of orientation-patterned (OP) templates, including such that are based on the most universal semiconductor material—Si. Still, the focus in this work is on a series of NLO materials—GaAs, GaP, ZnSe, GaSe, ZnTe, GaN… and some of their ternaries grown with high surface and crystalline quality on non-native substrates and on non-native OP templates using hydride vapor phase epitaxy (HVPE). The grown thick device quality QPM structures were used for further development of high power, compact, broadly tunable frequency conversion laser sources for the mid and longwave infrared with various applications in defense, security, industry, medicine and science.

scholarly journals Nonlinear Optics in Microspherical Resonators

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 303 ◽  
Author(s):  
Gabriele Frigenti ◽  
Daniele Farnesi ◽  
Gualtiero Nunzi Conti ◽  
Silvia Soria
Keyword(s):  
Frequency Conversion ◽  
Continuous Wave ◽  
Photonic Devices ◽  
Nonlinear Frequency ◽  
Normal Dispersion ◽  
Nonlinear Frequency Conversion ◽  
Whispering Gallery ◽  
Dispersion Regime ◽  
Long Time ◽  
Laser Sources

Nonlinear frequency generation requires high intensity density which is usually achieved with pulsed laser sources, anomalous dispersion, high nonlinear coefficients or long interaction lengths. Whispering gallery mode microresonators (WGMRs) are photonic devices that enhance nonlinear interactions and can be exploited for continuous wave (CW) nonlinear frequency conversion, due to their capability of confine light for long time periods in a very small volume, even though in the normal dispersion regime. All signals must be resonant with the cavity. Here, we present a review of nonlinear optical processes in glass microspherical cavities, hollow and solid.

scholarly journals Exploring Charge Transfer Mechanism in Organic NLO (Polymorphic) Materials

2014 ◽  
Vol 70 (a1) ◽  
pp. C378-C378
Author(s):  
Parthapratim Munshi ◽  
Kunal Jha
Keyword(s):  
Charge Transfer ◽  
Frequency Conversion ◽  
Structural Characteristics ◽  
Thiophene Ring ◽  
Industrial Applications ◽  
Transfer Mechanism ◽  
Chalcone Derivatives ◽  
Charge Transfer Mechanism ◽  
Nlo Materials ◽  
Polymorphic Forms

The understanding of nonlinear polarization mechanism and their relation to the structural characteristics of non-linear optical (NLO) materials have been utmost importance considering a surge in the information technology and industrial applications. Some investigations in search of NLO materials have been carried out on organic molecule scaffolds such as stilbene and chalcone having π-e-donor acceptor substituent which facilitates intermolecular charge transfer; leading to the generation of good frequency conversion materials. Few of such materials are known to exhibit polymorphic characters and most of which crystallize in non-centrosymmetric space group – necessity for a NLO material. It has been realized that the chirality, polymorphic character and NLO activity of the chalcone derivatives are mainly governed by both the substitutions at the para position and the position of sulfur atom in the thiophene ring of thienylchalcone. This presentation will highlight the preliminary results towards the analyses of electron density distributions on NLO active stilbene and chalcone derivatives and their polymorphic forms. Therefore, explore the charge transfer mechanism responsible for the variation of NLO activity across these systems and on their non-centrosymmetric polymorphic forms. Charge densities modelled using both multipole formalism (Hansen & Coppens, 1978) and X-ray constraint wavefunction fittings (Jayatilaka & Grimwood, 2001) will be considered for these studies.

Prospects of development of the reference base of the Russian Federation in the field of length measurements

2020 ◽  
pp. 3-5
Author(s):  
Y. G. Zakharenko ◽  
N. A. Kononova ◽  
V. L. Fedorin ◽  
Z. V. Fomkina ◽  
K. V. Chekirda
Keyword(s):  
High Precision ◽  
Russian Federation ◽  
Reference Base ◽  
Length Measurements ◽  
Laser Sources ◽  
The Russian Federation ◽  
Unit Of Length ◽  
Further Development ◽  
532 Nm

The results of the work to create a complex of high-precision hardware for the unit of length reproduction and transferring carried out at “D. I. Mendeleyev Institute for Metrology (VNIIM)” are represented. This complex will serve as the basis for the further development of the reference base of the Russian Federation in the field of length measurements and will allow reproduction of the unit of length at two wavelengths of 633 nm and 532 nm, as well as measurements of the wavelength of laser sources in vacuum in the range from 500 to 1050 nm.

Research on expanding the range of reproduction of magnetic flux density of the DC field of the state primary standard GET12-2011

2020 ◽  
pp. 3-7
Author(s):  
Vladlen Ya. Shifrin ◽  
Denis I. Belyakov ◽  
Alexander E. Shilov ◽  
Denis D. Kosenko
Keyword(s):  
Magnetic Flux ◽  
Magnetic Induction ◽  
Frequency Conversion ◽  
Magnetic Measurements ◽  
Primary Standard ◽  
Uncertainty Budget ◽  
The State ◽  
State Primary Standard ◽  
Magnetic Flux Density ◽  
Constant Field

The results of works aimed at increasing the level of uniformity of measurements of the magnetic induction of a constant field – the basic value in the field of magnetic measurements. A set of equipment for reproducing a unit of magnetic induction of a constant field in the range of 1–25 mT was created and described. The inclusion of this complex in the State primary standard of units of magnetic induction, magnetic flux, magnetic moment and magnetic induction gradient GET 12-2011 will ensure the reproduction and direct transmission of the unit of permanent magnetic induction in the ranges of not only weak (10–3–1 mT), but medium (1–25 mT) and strong (0.025–1 T) magnetic fields. A quantum cesium magnetometer based on the resolved structure of cesium atoms was created to transmit the unit of magnetic induction to the region of medium fields. The procedure for calculating the frequency conversion coefficients to magnetic induction of the created quantum cesium magnetometer is described. The uncertainty budget for reproducing a unit of magnetic induction of a constant field using the created complex is estimated.

A 24 mW 5.7 Gbps Dual Frequency Conversion Demodulator for Impulse Radio with the First Sidelobe

2016 ◽  
Vol E99.C (10) ◽  
pp. 1164-1173
Author(s):  
Kaoru KOHIRA ◽  
Naoki KITAZAWA ◽  
Hiroki ISHIKURO
Keyword(s):  
Frequency Conversion ◽  
Impulse Radio ◽  
Dual Frequency
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