MDPI - Publisher of Open Access Journals

13 pages, 1099 KB

Open AccessArticle

Comparison of Raman Spectra of Optically Nonlinear LiTaO₃:Cr³⁺ (0.005 wt%) Crystal Laser Excited in Visible (532 nm) and Near-IR (785 nm) Areas

by Mikhail Palatnikov, Nikolay Sidorov, Alexander Pyatyshev and Alexander Skrabatun

Photonics 2023, 10(4), 439; https://doi.org/10.3390/photonics10040439 - 12 Apr 2023

Cited by 5 | Viewed by 2266

Abstract

Raman spectra have been excited by the radiation of lasers generatingon in the visible (532 nm) and near-IR (785 nm) ranges in a LiTaO₃:Cr³⁺ (0.005 wt%) crystal. The obtained spectra were compared. Recorded Raman spectra contained bands in the range of <900 cm⁻¹ (first order) up to 2000 cm⁻¹ (second order). The Raman spectra of the second order, excited by near-IR laser radiation, were located against the background of a wide, luminescent halo. The frequency of a single low-intensity band exceeded the exact frequency of an overtone corresponding to the completely symmetric fundamental 4A₁(z)LO mode. The attribution of other second-order bands with higher frequencies remains unclear. Full article

(This article belongs to the Special Issue Lasers and Dynamic of Systems)

► Show Figures

Figure 1

9 pages, 1354 KB

Open AccessArticle

Raman Scattering in a Double-Doped Single Crystal LiTaO₃:Cr(0.2):Nd(0.45 wt%)

by Nikolay Sidorov, Mikhail Palatnikov and Alexander Pyatyshev

Photonics 2022, 9(10), 712; https://doi.org/10.3390/photonics9100712 - 29 Sep 2022

Cited by 5 | Viewed by 2176

Abstract

The Raman spectra of a lithium tantalate crystal doubly doped with chromium and neodymium LiTaO₃:Cr(0.2):Nd(0.45 wt%) have been studied in this paper. Raman spectra of the first and second orders have been found to be located against the background of a luminescent halo with a maximum at ≈1250 cm⁻¹. Several Raman bands have been detected in the frequency range of 900–2000 cm⁻¹. Their frequencies were 940, 1034, 1113, 1171, 1250, 1343, 1428, 1491, 1582, 1735, 1838, and 1925 cm⁻¹. These bands correspond to overtone processes. We have determined that the frequencies of 1838 and 1925 cm⁻¹ bands are significantly higher than the exact value of the overtone frequency corresponding to the fundamental mode 4A₁(z)LO (864 cm⁻¹). Full article

(This article belongs to the Section Optoelectronics and Optical Materials)

► Show Figures

Figure 1

10 pages, 19907 KB

Open AccessEditor’s ChoiceArticle

Second-Order Raman Scattering in Ferroelectric Ceramic Solid Solutions LiNb_xTa_1−xO₃

by Nikolay Sidorov, Mikhail Palatnikov, Alexander Pyatyshev and Pavel Sverbil

Crystals 2022, 12(4), 456; https://doi.org/10.3390/cryst12040456 - 24 Mar 2022

Cited by 10 | Viewed by 2560

Abstract

In the second-order Raman spectra of ceramic solid solutions, LiNb_xTa_1−xO₃ weak overtone bands of fully symmetric fundamental polar excitations were observed for the first time. The frequencies of the two bands exceeded the value of the overtone frequency corresponding to the fully symmetrical vibration 4A₁(z). The possibility of the existence of phonon bound states of the antipolar type in the vibrational spectrum of LiNb_xTa_1−xO₃ ceramics is predicted. Full article

(This article belongs to the Special Issue Multiferroic Ceramics and Thin Film Nanostructures for Logic and Memory Applications)

► Show Figures

Figure 1

Search Results (3)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (3)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI