Optical characterization of thermal lens effect in ethanol and the influence of focusing lens and liquid cell size

Mahdieh, Mohammad Hossein; Jafarabadi, Marzieh Akbari

doi:10.1016/j.optlastec.2011.05.023

Cited by 34 publications

(7 citation statements)

References 23 publications

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“…The angle between the linearly polarized probe and the excitation pulses was set as the magic angle (54.7°) to obtain an isotropic absorbance proportional to the population of the corresponding compounds free from molecular rotation. The energy of the excitation pulse was reduced to 1–2 μJ to ensure linear absorbance and to minimize thermal lensing, which causes high background absorption on the nanosecond time scale due to solvent heating [ 21 , 22 , 23 , 24 , 25 ]. To measure the spectral region beyond the spectral width (160 cm −1 ) of the probe pulses, the experiment was repeated with probe pulses centered at 1300, 1230, 1160, 1080, or 950 cm −1 , and the data were combined to obtain a broad spectrum.…”

Section: Methodsmentioning

confidence: 99%

“…The temperature of the sample was maintained at 280 ± 2 K by passing the coolant through the sample mount block. The low temperature was beneficial in minimizing the noise in the TRIR spectra caused by the temperature gradient in the probe spot of the sample induced by the pump energy (i.e., thermal lensing) appearing on the nano- to microsecond time scale [ 21 , 22 , 23 , 24 , 25 ]. To ensure the integrity of the samples, equilibrium UV–Vis and FT-IR spectra were collected before and after the TRIR experiments.…”

Section: Methodsmentioning

confidence: 99%

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Investigating the Photodissociation Dynamics of CF2BrCF2I in CCl4 through Femtosecond Time-Resolved Infrared Spectroscopy

Park

Shin

Lim

2023

IJMS

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The photodissociation dynamics of CF2BrCF2I in CCl4 at 280 ± 2 K were investigated by probing the C−F stretching mode from 300 fs to 10 μs after excitation at 267 nm using time-resolved infrared spectroscopy. The excitation led to the dissociation of I or Br atoms within 300 fs, producing the CF2BrCF2 or CF2ICF2 radicals, respectively. All nascent CF2ICF2 underwent further dissociation of I, producing CF2CF2 with a time constant of 56 ± 5 ns. All nascent g-CF2BrCF2 isomerized into the more stable a-CF2BrCF2 with a time constant of 47 ± 5 ps. Furthermore, a-CF2BrCF2 underwent a bimolecular reaction with either itself (producing CF2BrCF2Br and CF2CF2) or Br in the CCl4 solution (producing CF2BrCF2Br) at a diffusion-limited rate. The secondary dissociation of Br from a-CF2BrCF2 was significantly slow to compete with the bimolecular reactions. Overall, approximately half of the excited CF2BrCF2I at 267 nm produced CF2BrCF2Br, whereas the other half produced CF2CF2. The excess energies in the nascent radicals were thermalized much faster than the secondary dissociation of I from CF2ICF2 and the observed bimolecular reactions, implying that the secondary reactions proceeded under thermal conditions. This study further demonstrates that structure-sensitive time-resolved infrared spectroscopy can be used to study various reaction dynamics in solution in real time.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Investigating the Photodissociation Dynamics of CF2BrCF2I in CCl4 through Femtosecond Time-Resolved Infrared Spectroscopy

Park

Shin

Lim

2023

IJMS

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“…τ 0 is transmittance of optical system, Ω is stretched solid angle from the center of the flying target to entrance pupil area of optical system, τ a is the average passing rate of atmosphere path. Ω is entrance pupil area of optical system, D is entrance pupil diameter (Mahdieh and Akbari, 2012).…”

Section: Detection Distance Calculation Function Of Infrared Photoelectric Detection Systemmentioning

confidence: 99%

Target infrared radiation calculation model and method based on finite element analysis method in infrared photoelectric detection system

2017

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Purpose The purpose of this paper is to evaluate the detection performance of infrared photoelectric detection system and establish stable tracking platform. Design/methodology/approach This paper puts forward making use of the finite element analysis method to set up the infrared radiation characteristics calculation model of flying target in infrared photoelectric detection system; researches the target optical characteristics based on the target imaging detection theory; sets up the heat balance equation of target’s surface node and gives the calculation method of total radiation intensity of flying target; and deduces the target detection distance calculation function; studies the changed regulation of radiation energy that charge coupled device (CCD) gain comes from target surface infrared heat radiations under different sky background luminance and different target flight attitude. Findings Through calculation and experiment analysis, the results show that when the target’s surface area increases or the target flight velocity is higher, the radiation energy that CCD obtained is higher, which is advantageous to the target stable detection in infrared photoelectric detection system. Originality/value This paper uses the finite element analysis method to set up the infrared radiation characteristics calculation model of flying target and give the calculation and experiment results; those results can provide some data and improve the design method of infrared photoelectric detection system, and it is of value.

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“…Therefore, TL signal may be considered as an effective structural representative of the sample. Due to the high sensitivity of TL measurement method, it is considered as a suitable optical characterization for a variety of samples, especially for detection of low concentrations of analytes in low absorbing samples as well as a photothermal detector integrated with gel electrophoresis [12][13][14] . It is also remarkable that, since DHM can extract the optical phase difference function of the sample, it may be considered as an alternative to measure the absorption coefficient using the TL effect 15,16 .…”

Section: Introductionmentioning

confidence: 99%

Microsphere-Assisted Digital Holographic Microscopy Integrated with On-Line Thermal Lens Spectrometry for 3d Imaging and Enhanced Photothermal Detection

Kabi

Moradi

Cabrera³

2022

SSRN Journal

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Optical characterization of thermal lens effect in ethanol and the influence of focusing lens and liquid cell size

Cited by 34 publications

References 23 publications

Investigating the Photodissociation Dynamics of CF2BrCF2I in CCl4 through Femtosecond Time-Resolved Infrared Spectroscopy

Investigating the Photodissociation Dynamics of CF2BrCF2I in CCl4 through Femtosecond Time-Resolved Infrared Spectroscopy

Target infrared radiation calculation model and method based on finite element analysis method in infrared photoelectric detection system

Microsphere-Assisted Digital Holographic Microscopy Integrated with On-Line Thermal Lens Spectrometry for 3d Imaging and Enhanced Photothermal Detection

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