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Broadband fluorescence emission and laser demonstration in large mode waveguide structure in Yb3+ doped germanate glass

Khalid Mamoona

Optica Applicata

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2021

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Vol. 51, nr 1

75--85

EN

A stable composition (against crystallization) of germanate glass doped with Yb3+ for mid-infrared laser applications is presented. Broad emission spectrum of Yb3+ was obtained for the fabricated glass. Laser operation was demonstrated in 13 mm long waveguide written in the glass using a femtosecond laser operating at 524 nm center wavelength sending 250 fs ultrashort pulses. The resulting CW laser operated at 1.04 μm in the fundamental mode of the waveguide. The propagation loss through the waveguide was 0.6 dB/cm at 1550 nm for 45 μm diameter of the modified structure. The mode analysis of the developed waveguide structure is also presented in COMSOL Multiphysics to study the electric field distribution through different modes of propagation in the waveguide and the confinement loss associated to them.

2

Synthesis and investigation of nonlinear optical properties of Para Red: Z-scan technique end quantum mechanical calculations

Mostaghni F., Abed Y.

Materials Science Poland

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2018

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Vol. 36, No. 3

445--451

EN

In this study, we present a systematic study of linear and nonlinear optical properties of Para Red with the aim of Z-scan technique and quantum mechanical calculations. The Z-scan experiments were performed using a 532 nm Nd: YAG (SHG) CW laser beam. Para Red exhibited a strong nonlinear refractive index, nonlinear absorption coefficient and third-order nonlinear susceptibility 3.487 × 10-6 cm2/W, 2.341 × 10-1 cm/W and 2.157 × 10-4 esu, respectively. Also, quantum chemical analysis was used for the calculation of the dipole moment µ, dipole polarizability α, anisotropy of polarizability Δα and molecular hyperpolarizabilities (β, γ). The results revealed that Para Red has large first and second hyperpolarizabilities. However, from the obtained results, it was found that Para Red can be a promising material for applications in the development of non-linear optical materials.

3

Effect of viscosity on the far-field diffraction pattern of spatial self-phase modulation

Nibu A. G., Silpa S. S., Ardra S. N., Anisha M. M., Ambika D.

Optica Applicata

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2017

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Vol. 47, nr 4

591--599

EN

Effect of viscosity of a liquid on the far-field diffraction pattern due to spatial self-phase modulation is investigated. Chlorophyll extract in acetone at different concentrations is used as the low viscous nonlinear samples and commercial engine oils, synthetic and natural. It is also used as high viscous media. In the case of chlorophyll solution, the self-induced diffraction ring pattern in the far-field is a series of circular rings at the beginning; but later it is transformed to half circular symmetry. But for the high viscous engine oils we have observed circular fringes and there is no time dependent structural variation in the pattern. The coefficient of the intensity dependent nonlinear refractive index for all the liquid samples is evaluated.

4

Dependence of nonlinear refractive index of ZnSe on Be and Mg content

Derkowska B., Firszt F., Marasek A., Sahraoui B.

Opto-Electronics Review

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2010

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Vol. 18, No. 4

384-387

EN

The values of the nonlinear refractive index n₂ and the two-photon absorption coefficient ß of ternary and quaternary ZnSe-based mixed crystals were extracted from the standard backward degenerate four wave mixing (DFWM) and nonlinear transmission measurements at 532 nm, respectively. Studied crystals were grown by the modified high-pressure Bridgman method. We found that the value of the nonlinear refractive index n2 for Zn0.79Be0.21Se is higher than that for Zn0.80Mg0.20Se. However, the opposite behaviour was found in the case of two-photon absorption coefficient ß for these compounds. We also found that the values of the nonlinear refractive index n2 and the two-photon absorption coefficient ß for Zn0.83Be0.04Mg0.13Se are about five times lower and three times higher than that for Zn0.80Mg0.13Se, respectively. In the case of ternary ZnSe-based crystals we noticed that the value of the nonlinear refractive index n2 decreases with increasing Mg or Be content. However, the value of the two-photon absorption coefficient ß increases with increasing Mg or Be content.

5

Szkło nieliniowe dla fotoniki. Cz. 3, Nieliniowość refrakcyjna szkła

Romaniuk R.

Elektronika : konstrukcje, technologie, zastosowania

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2008

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Vol. 49, nr 5

83-88

PL

W artykule, który jest trzecią częścią cyklu prac o szkłach nieliniowych, przedstawiono i opisano czynniki bezpośrednio decydujące o nieliniowej refrakcji. Omówiono różnice pomiędzy nieliniową refrakcją w objętościowych próbkach szkła i w długich, ultraniskostratnych światłowodach jednomodowych. Opisano refrakcyjne efekty nieliniowe pierwszego rzędu (kwadratowe). Podano tabelaryczne wartości nieliniowej refrakcji różnych rodzin szkieł optycznych dla fotoniki. Refrakcyjne efekty nieliniowe różnicowano przez ich charakterystyczne czasy relaksacji. Dualnym zjawiskiem do nieliniowej refrakcji szkła, przez zależności Kramersa-Kroniga, jest jego nieliniowa absorpcja. Odrębnym zagadnieniem jest nieliniowa dyspersja.

EN

The paper, which is the third part of a cycle on nonlinear glasses, presents and describes the factors directly influencing the nonlinear refraction. There are debated differences between nonlinear refraction in the volume samples of glasses and long, ultra-low-loss, single-mode optical fibers. There are described nonlinear refractive effects of the first order (quadratic). Nonlinear refraction coefficients for various optical glasses for photonics were gathered in tables. The nonlinear refractive effects are differentiated by their characteristic relaxation times. A dual phenomena to nonlinear refraction is nonlinear absorption, via the Kramers-Kronig relations. A separate subject is nonlinear dispersion of glasses.