Raman Apparatus Using Laser Excitation and Polarization Measurements. Rotational Spectrum of Fluorine

1969 ◽  
Vol 23 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Howard H. Claassen ◽  
Henry Selig ◽  
Jacob Shamir
Keyword(s):  
Laser Beam ◽  
Raman Spectra ◽  
Laser Excitation ◽  
Scattered Light ◽  
Rotational Constant ◽  
Emission Lines ◽  
Optical Systems ◽  
Rotational Spectrum ◽  
Polarization Measurements

Various schemes are compared for measuring depolarization factors in Raman spectra with laser excitation. Optical systems are discussed for producing a laser beam free of unwanted emission lines and for focusing scattered light on the slit and on the detector. The rotational spectrum of gaseous F2 has been used to determine a rotational constant of Bo=0.8841 ±0.0006 cm−1, corresponding to r0=1.4168±0.0005 Å.

The structure of complexes of HCl withN,N-dimethylformamide based on polarization measurements in the Raman spectra

1998 ◽  
Vol 47 (1) ◽  
pp. 46-49 ◽  
Author(s):  
V. V. Burdin ◽  
I. S. Kislina ◽  
V. D. Maiorov ◽  
N. B. Librovich
Keyword(s):  
Raman Spectra ◽  
Polarization Measurements

scholarly journals Discovering the forbidden Raman modes at the edges of layered materials

2018 ◽  
Vol 4 (12) ◽  
pp. eaau6252 ◽  
Author(s):  
Yao Guo ◽  
Weixuan Zhang ◽  
Hanchun Wu ◽  
Junfeng Han ◽  
Yongliang Zhang ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Electromagnetic Fields ◽  
Scattered Light ◽  
Layered Materials ◽  
The Body ◽  
Body Region ◽  
Edge Type ◽  
Body Regions ◽  
Raman Modes ◽  
Raman Study

The edges of layered materials have unique properties that substantially differ from the body regions. In this work, we perform a systematic Raman study of the edges of various layered materials (MoS2, WS2, WSe2, PtS2, and black phosphorus). The Raman spectra of the edges feature newly observed forbidden Raman modes, which are originally undetectable from the body region. By selecting the edge type and the polarization directions of the incident and scattered light, all forbidden Raman modes are distinctly detected. Optical simulations show that the edges of layered materials drastically distort the electromagnetic fields of both the incident and scattered light, so that the light interacts with the edges in a distinct way, which differs from its interactions with the body regions.

Methods for Determining the Characteristics of Laser Beams and the Optical Transmission

2014 ◽  
Vol 656 ◽  
pp. 345-350
Author(s):  
Iulian Nicola ◽  
Tudor Prisecaru
Keyword(s):  
Laser Beam ◽  
Experimental Measurement ◽  
Optical Transmission ◽  
Optical Systems ◽  
Laser Beams ◽  
Laser Rangefinder ◽  
New Methods

The paper presents new methods and procedures to measure the characteristics of laser beams and their transmission through optical systems. The paper describes the work procedures and equipments used to measure the characteristics of laser beams and their transmission through optical systems. Using these working procedures, experimental measurement for the characteristics of the beam for a 1.54 µm laser rangefinder and the transmission of a 633 nm laser beam through laser protection glasses were made.

Raman spectra of twisted bilayer graphene close to the magic angle

2D Materials ◽  
2022 ◽  
Author(s):  
Tiago Campolina Barbosa ◽  
Andreij C. Gadelha ◽  
Douglas A. A. Ohlberg ◽  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Laser Excitation ◽  
Bilayer Graphene ◽  
Geometrical Model ◽  
Excitation Wavelength ◽  
Magic Angle ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Excitation Laser ◽  
Twisted Bilayer Graphene

Abstract In this work, we study the Raman spectra of twisted bilayer graphene samples as a function of their twist-angles (θ), ranging from 0.03º to 3.40º, where local θ are determined by analysis of their associated moiré superlattices, as imaged by scanning microwave impedance microscopy. Three standard excitation laser lines are used (457, 532, and 633 nm wavelengths), and the main Raman active graphene bands (G and 2D) are considered. Our results reveal that electron-phonon interaction influences the G band's linewidth close to the magic angle regardless of laser excitation wavelength. Also, the 2D band lineshape in the θ < 1º regime is dictated by crystal lattice and depends on both the Bernal (AB and BA) stacking bilayer graphene and strain soliton regions (SP) [1]. We propose a geometrical model to explain the 2D lineshape variations, and from it, we estimate the SP width when moving towards the magic angle.

R-Line Luminescence from Trace Amounts of Cr3+ in Aluminum Oxide and its Dependence on Sample Hydration

2002 ◽  
Vol 56 (8) ◽  
pp. 1055-1058 ◽  
Author(s):  
Chen Zuo ◽  
Paul W. Jagodzinski
Keyword(s):  
Aluminum Oxide ◽  
Raman Spectra ◽  
Laser Excitation ◽  
Sample Surface ◽  
Optical Spectra ◽  
Water Molecules ◽  
Commercial Products ◽  
Degree Of Hydration ◽  
Setting Reaction ◽  
Octahedral Sites

The R-line luminescence is observed in the Raman spectra of α- and γ-Al2O3 with chromium concentrations of less than 1 ppm. The same signals were previously used to monitor the setting reaction of dental cements. With laser excitation <690 nm, the R-line luminescence can be observed in the optical spectra of most commercial products containing α-Al2O3. It is found that the intensities of R-line signals are related to the degree of hydration of the α-Al2O3 sample, which can be explained by the formation of additional octahedral sites for Cr3+ near the sample surface involving oxygen atoms from the Al2O3 matrix and from absorbed water molecules.

Dependence of the Raman spectra of drug substances upon laser excitation wavelength

2006 ◽  
Vol 37 (1-3) ◽  
pp. 335-341 ◽  
Author(s):  
Fiona C. Thorley ◽  
Kurt J. Baldwin ◽  
David C. Lee ◽  
David N. Batchelder
Keyword(s):  
Raman Spectra ◽  
Laser Excitation ◽  
Excitation Wavelength ◽  
Drug Substances

Resonance Raman Spectra of Aqueous Pollen Suspensions with 222.5–242.4-nm Pulsed Laser Excitation

1991 ◽  
Vol 45 (2) ◽  
pp. 307-311 ◽  
Author(s):  
R. Manoharan ◽  
E. Ghiamati ◽  
K. A. Britton ◽  
W. H. Nelson ◽  
J. F. Sperry
Keyword(s):  
Raman Spectra ◽  
Laser Excitation ◽  
Resonance Raman ◽  
Pulsed Laser ◽  
Resonance Raman Spectra

Raman-Spektren eines AsJ3-Einkristalls und von SbJ3-und BiJ3-Kristallpulvern / Raman spectra of an AsJ3-single crystal and of SbJ3- and BiJ3--crystal powders

1970 ◽  
Vol 25 (7) ◽  
pp. 1101-1107 ◽  
Author(s):  
W. Kiefer
Keyword(s):  
Single Crystal ◽  
Raman Spectra ◽  
Ruby Laser ◽  
Factor Group ◽  
Unit Cell ◽  
Space Group ◽  
Polarization Measurements ◽  
Double Monochromator ◽  
Depolarization Ratios

Raman spectra of an AsJ3-single crystal were recorded using a quasicontinuous ruby laser, a double monochromator and a special registration electronics. The polarization measurements allow the assignments of the internal, translational and rotational modes of AsJ3 (factor group S6). Since SbJ3 and BiJ3 have the same space group and the same number of molecules per unit cell, one can assign the wavenumbers of the crystal powder Raman spectra in analogy to AsJ3. The depolarization ratios of the Raman lines of AsJ3 in solutions were also determined

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