Use of multi-notch filter for simultaneous recording of stokes and anti-Stokes Raman signals close to the exciting line

A Raman microprobe with a holographic beamsplitter is described. The beamsplitter is shown to have 90% laser insertion efficiency and high Raman transmission efficiency on both the Stokes and anti-Stokes side. Useful spectra are obtainable as close as ±60 cm−1 from the exciting line using 4 mW power.

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Construction and Operation of a dispersive Laser Raman Spectrograph using interference filter

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v32i1.2451 ◽

1970 ◽

Vol 32 (1) ◽

pp. 121-129

Author(s):

KM Abedin ◽

SFU Farhad ◽

MR Islam ◽

Aminul I Talukder ◽

AFMY Haider

Keyword(s):

Raman Spectra ◽

Notch Filter ◽

Ccd Camera ◽

Interference Filter ◽

Spectral Lines ◽

Quantitative Chemical Analysis ◽

Laser Raman ◽

Holographic Notch Filter ◽

Cooled Ccd ◽

Anti Stokes

A dispersive laser Raman system was designed and constructed using a helium-neon (He-Ne) laser as an excitation source, and an interference filter in the reflection mode for Raleigh filtering instead of the more common holographic notch filter. A commercially available spectrograph equipped with a cooled CCD camera was used to acquire the Raman spectra. The constructed laser Raman spectrograph was found to have excellent performance and sensitivity. Stokes Raman spectra of some common chemicals were acquired by the system, and the wavelengths of spectral lines agreed well with the literature values, within experimental error. The useful spectral range of the system is about 200-4000 cm-1. It was also possible to acquire anti-Stokes Raman spectra of one chemical (CCl4) without much difficulty. We hope to use the system for chemical identification of molecules as well as quantitative chemical analysis. To our knowledge, this is the first laser Raman system constructed in Bangladesh. doi: 10.3329/jbas.v32i1.2451 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 121-129, 2008

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Performance of a Holographic Supernotch Filter

Applied Spectroscopy ◽

10.1366/0003702934066776 ◽

1993 ◽

Vol 47 (3) ◽

pp. 305-308 ◽

Cited By ~ 43

Author(s):

Christian L. Schoen ◽

Shiv K. Sharma ◽

Charles E. Helsley ◽

Harry Owen

Keyword(s):

Raman Spectroscopy ◽

Raman Spectra ◽

Comparative Evaluation ◽

Low Frequency ◽

Notch Filter ◽

Rayleigh Line ◽

Rejection Filter ◽

Excitation Line ◽

Holographic Notch Filter ◽

Anti Stokes

Results are presented of a comparative evaluation of a holographic supernotch filter (HSNF) and a holographic notch filter (HNF) as a Rayleigh line rejection filter for Raman spectroscopy. The filter permits acquisition of both Stokes and anti-Stokes spectra down to ±200 cm−1 shift from excitation simultaneously, without filter angle adjustment. With slight angle adjustment, spectra can be recorded as close as 41 cm−1 from the excitation line. Performance of the HSNF is evaluated by measuring the low-frequency Raman spectra of Tb2(MoO4)3, water, and naphthalene.

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Simultaneous recording of pseudoaffective reflexes and motor activity in the jejunum of the anesthetized rat

Gastroenterology ◽

10.1016/s0016-5085(01)83569-1 ◽

2001 ◽

Vol 120 (5) ◽

pp. A717-A717

Author(s):

A TIMARPEREGRIN ◽

K KUMANO ◽

Z KHALIL ◽

G SANGER ◽

S BEECHAM ◽

...

Keyword(s):

Motor Activity ◽

Simultaneous Recording

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Olfactory Modulation of Steady- State Visual Evoked Potential Topography in Comparison with Differences in Odor Sensitivity

Journal of Psychophysiology ◽

10.1027//0269-8803.16.2.71 ◽

2002 ◽

Vol 16 (2) ◽

pp. 71-81 ◽

Cited By ~ 2

Author(s):

Caroline M. Owen ◽

John Patterson ◽

Richard B. Silberstein

Keyword(s):

Steady State ◽

Visual Evoked Potential ◽

Evoked Potential ◽

Behavioral Responses ◽

Simultaneous Recording ◽

Odor Concentration ◽

Odor Detection ◽

Detection Response ◽

Response Groups ◽

Visual Evoked

Summary Research was undertaken to determine whether olfactory stimulation can alter steady-state visual evoked potential (SSVEP) topography. Odor-air and air-only stimuli were used to determine whether the SSVEP would be altered when odor was present. Comparisons were also made of the topographic activation associated with air and odor stimulation, with the view toward determining whether the revealed topographic activity would differentiate levels of olfactory sensitivity by clearly identifying supra- and subthreshold odor responses. Using a continuous respiration olfactometer (CRO) to precisely deliver an odor or air stimulus synchronously with the natural respiration, air or odor (n-butanol) was randomly delivered into the inspiratory airstream during the simultaneous recording of SSVEPs and subjective behavioral responses. Subjects were placed in groups based on subjective odor detection response: “yes” and “no” detection groups. In comparison to air, SSVEP topography revealed cortical changes in response to odor stimulation for both response groups, with topographic changes evident for those unable to perceive the odor, showing the presence of a subconscious physiological odor detection response. Differences in regional SSVEP topography were shown for those who reported smelling the odor compared with those who remained unaware of the odor. These changes revealed olfactory modulation of SSVEP topography related to odor awareness and sensitivity and therefore odor concentration relative to thresholds.

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