A. Chaikovsky, M. Korol, A. Malinka, E. Zege, I. Katsev, A. Prikhach, S. Denisov, V. Dick, P. Goloub, L. Blarel, L. Chaikovskaya, A. Lapyonok, T. Podvin, N. Denishchik-Nelubina, A. Fedarenka, V. Svidinsky
The paper presents lecture materials given at the Nineteenth International Conference and School on Quantum Electronics “Laser Physics and Applications” (19th ICSQE) in 2016, Sozopol, Bulgaria and contains the results of the 10-year research of Belarusian Antarctic expeditions to study the atmospheric aerosol and Earth surface in Antarctica. The works focus on the studying variability and trends of aerosol, cloud and snow characteristics in the Antarctic and the links of these processes with the long range transport of atmospheric pollutants and climate changes.
{"title":"Combined ground-based and satellite remote sensing of atmospheric aerosol and Earth surface in the Antarctic","authors":"A. Chaikovsky, M. Korol, A. Malinka, E. Zege, I. Katsev, A. Prikhach, S. Denisov, V. Dick, P. Goloub, L. Blarel, L. Chaikovskaya, A. Lapyonok, T. Podvin, N. Denishchik-Nelubina, A. Fedarenka, V. Svidinsky","doi":"10.1117/12.2261794","DOIUrl":"https://doi.org/10.1117/12.2261794","url":null,"abstract":"The paper presents lecture materials given at the Nineteenth International Conference and School on Quantum Electronics “Laser Physics and Applications” (19th ICSQE) in 2016, Sozopol, Bulgaria and contains the results of the 10-year research of Belarusian Antarctic expeditions to study the atmospheric aerosol and Earth surface in Antarctica. The works focus on the studying variability and trends of aerosol, cloud and snow characteristics in the Antarctic and the links of these processes with the long range transport of atmospheric pollutants and climate changes.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123704414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Dakova, A. Dakova, V. Slavchev, P. Staykov, L. Kovachev
In last two decades the phenomena resulting from the evolution of ultra-short laser pulses in nonlinear dispersive medium actively are being studied. The most commonly used equation for describing the dynamics of optical pulses in one-dimensional and planar waveguides is the standard nonlinear Schrodinger equation (NSE). It works very well for nanosecond and picosecond laser pulses, but in the frames of femtosecond optics, it is necessary two additional terms to be included. They are responsible for higher order of linear dispersion and dispersion of nonlinearity. These effects are significant in the range of ultra-short light pulses. In the present paper, it is presented a theoretical model of the propagation of optical solitons. We found an exact analytical soliton solution of the modified NSE, including third order of linear dispersion and dispersion of nonlinearity. It is possible to observe a soliton as a result of the dynamic balance between effects of higher order of dispersion and nonlinearity.
{"title":"Soliton propagation in isotropic media under the influence of third order of linear dispersion and dispersion of nonlinearity","authors":"D. Dakova, A. Dakova, V. Slavchev, P. Staykov, L. Kovachev","doi":"10.1117/12.2263442","DOIUrl":"https://doi.org/10.1117/12.2263442","url":null,"abstract":"In last two decades the phenomena resulting from the evolution of ultra-short laser pulses in nonlinear dispersive medium actively are being studied. The most commonly used equation for describing the dynamics of optical pulses in one-dimensional and planar waveguides is the standard nonlinear Schrodinger equation (NSE). It works very well for nanosecond and picosecond laser pulses, but in the frames of femtosecond optics, it is necessary two additional terms to be included. They are responsible for higher order of linear dispersion and dispersion of nonlinearity. These effects are significant in the range of ultra-short light pulses. In the present paper, it is presented a theoretical model of the propagation of optical solitons. We found an exact analytical soliton solution of the modified NSE, including third order of linear dispersion and dispersion of nonlinearity. It is possible to observe a soliton as a result of the dynamic balance between effects of higher order of dispersion and nonlinearity.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125218449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reviews recent progresses in ultrafast laser-based X-ray sources and their potential applications to high throughput X-ray imaging. Prospects for the utilization of X-rays sources related to the Laser Wakefield electron Acceleration (LWFA) are more specifically discussed with emphasis on application in diagnostic radiology.
{"title":"The ultrafast high-peak power lasers in future biomedical and medical x-ray imaging","authors":"J. Kieffer, S. Fourmaux, A. Król","doi":"10.1117/12.2261795","DOIUrl":"https://doi.org/10.1117/12.2261795","url":null,"abstract":"This paper reviews recent progresses in ultrafast laser-based X-ray sources and their potential applications to high throughput X-ray imaging. Prospects for the utilization of X-rays sources related to the Laser Wakefield electron Acceleration (LWFA) are more specifically discussed with emphasis on application in diagnostic radiology.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"229 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116437877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper we have demonstrated coherent population trapping and Rydberg state excitation in the five level media. We have analysed the influence of non zero multiphoton detunings and the self-phase modulation on these processes.
{"title":"Coherent population trapping in five-level system","authors":"E. Gazazyan","doi":"10.1117/12.2258620","DOIUrl":"https://doi.org/10.1117/12.2258620","url":null,"abstract":"In this paper we have demonstrated coherent population trapping and Rydberg state excitation in the five level media. We have analysed the influence of non zero multiphoton detunings and the self-phase modulation on these processes.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127115528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present experimental and theoretical investigation of the first picoseconds of formation of white continuum from 100 fs laser pulse in 0.5 cm BK7 glass. The theory gives an answer to the question of the physical mechanism of asymmetrical ultra-broadening of the pulses in the initial moment of filamentation. The spectra obtained from the experiment are compared with the spectrum profiles of the physical model and are in very good coincidence.
本文对100fs激光脉冲在0.5 cm BK7玻璃中形成白色连续体的第一皮秒进行了实验和理论研究。该理论给出了在成丝初始时刻脉冲不对称超展宽的物理机制的答案。将实验所得的光谱与物理模型的光谱曲线进行了比较，两者吻合良好。
{"title":"Avalanche parametric conversion in the initial moment of filamentation","authors":"D. Georgieva, L. Kovachev, N. Nedyalkov","doi":"10.1117/12.2263483","DOIUrl":"https://doi.org/10.1117/12.2263483","url":null,"abstract":"We present experimental and theoretical investigation of the first picoseconds of formation of white continuum from 100 fs laser pulse in 0.5 cm BK7 glass. The theory gives an answer to the question of the physical mechanism of asymmetrical ultra-broadening of the pulses in the initial moment of filamentation. The spectra obtained from the experiment are compared with the spectrum profiles of the physical model and are in very good coincidence.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127264278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Stoykova, D. Nazarova, N. Berberova, A. Gotchev, B. Ivanov, G. Mateev
Dynamic laser speckle analysis is non-destructive detection of physical or biological activity through statistical processing of speckle patterns on the surface of diffusely reflecting objects. This method is sensitive to microscopic changes of the surface over time and needs simple optical means. Advances in computers and 2D optical sensors forced development of pointwise algorithms. They rely on acquisition of a temporal sequence of correlated speckle images and generate activity data as a 2D spatial contour map of the estimate of a given statistical parameter. The most widely used pointwise estimates are the intensity-based estimates which compose each map entry from a time sequence of intensity values taken at one and the same pixel in the acquired speckle images. Accuracy of the pointwise approach is strongly affected by the signal-dependent nature of the speckle data when the spread of intensity fluctuations depends on the intensity itself. The latter leads to erroneous activity determination at non-uniform distribution of intensity in the laser beam for the non-normalized estimates. Normalization of the estimates, introduces errors. We propose to apply binarization to the acquired speckle images by comparing the intensity values in the temporal sequence for a given spatial point to the mean intensity value estimated for this point and to evaluate a polar correlation function. Efficiency of this new processing algorithm is checked both by simulation and experiment.
{"title":"Dynamic laser speckle metrology with binarization of speckle patterns","authors":"E. Stoykova, D. Nazarova, N. Berberova, A. Gotchev, B. Ivanov, G. Mateev","doi":"10.1117/12.2262330","DOIUrl":"https://doi.org/10.1117/12.2262330","url":null,"abstract":"Dynamic laser speckle analysis is non-destructive detection of physical or biological activity through statistical processing of speckle patterns on the surface of diffusely reflecting objects. This method is sensitive to microscopic changes of the surface over time and needs simple optical means. Advances in computers and 2D optical sensors forced development of pointwise algorithms. They rely on acquisition of a temporal sequence of correlated speckle images and generate activity data as a 2D spatial contour map of the estimate of a given statistical parameter. The most widely used pointwise estimates are the intensity-based estimates which compose each map entry from a time sequence of intensity values taken at one and the same pixel in the acquired speckle images. Accuracy of the pointwise approach is strongly affected by the signal-dependent nature of the speckle data when the spread of intensity fluctuations depends on the intensity itself. The latter leads to erroneous activity determination at non-uniform distribution of intensity in the laser beam for the non-normalized estimates. Normalization of the estimates, introduces errors. We propose to apply binarization to the acquired speckle images by comparing the intensity values in the temporal sequence for a given spatial point to the mean intensity value estimated for this point and to evaluate a polar correlation function. Efficiency of this new processing algorithm is checked both by simulation and experiment.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"10226 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131046238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Todorov, V. Polischuk, A. Krasteva, S. Cartaleva, A. Sargsyan, T. Vartanyan
The fluorescence and non-linear absorption spectra of Cs133 vapour in an extremely thin cell were calculated by using the perturbation theory with respect to the pumping field intensity. The problem of the atoms’ non-linear polarization was solved for arbitrary values of the total momenta of the resonance levels pumped by a linearly-polarised laser field. It was demonstrated that the spontaneous emission from the upper level affects the amplitude and sign of the lower level longitudinal alignment and results in a change of the amplitude and sign of the non-linear absorption resonance at the closed transition. The comparison of the numerical calculations with the experimental data for the D2 line of 133Cs shows a very good agreement.
{"title":"Nonlinear resonances sign reversal and longitudinal alignment on the resonant levels of 133Cs thin-layer vapour","authors":"G. Todorov, V. Polischuk, A. Krasteva, S. Cartaleva, A. Sargsyan, T. Vartanyan","doi":"10.1117/12.2263622","DOIUrl":"https://doi.org/10.1117/12.2263622","url":null,"abstract":"The fluorescence and non-linear absorption spectra of Cs133 vapour in an extremely thin cell were calculated by using the perturbation theory with respect to the pumping field intensity. The problem of the atoms’ non-linear polarization was solved for arbitrary values of the total momenta of the resonance levels pumped by a linearly-polarised laser field. It was demonstrated that the spontaneous emission from the upper level affects the amplitude and sign of the lower level longitudinal alignment and results in a change of the amplitude and sign of the non-linear absorption resonance at the closed transition. The comparison of the numerical calculations with the experimental data for the D2 line of 133Cs shows a very good agreement.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134538990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper presents our results on the study of the efficiency of inter-fractional changes in hemoglobin molecules depending on the laser radiation parameters. The evaluation of the quantum efficiency of light interaction in vivo with oxyhemoglobin (HbO2) and carboxyhemoglobin (HbCO) in the blood at wavelengths for 525 and 605 nm is presented. The photodissociation yield of 11% for HbO2 and 79% for HbCO are measured at the wavelength of 525 nm and 10 % for HbO2 and 76 % for HbCO at a wavelength of 605 nm. Thus, the quantum yield of photodissociation of the HbCO is considerably higher, which ensures high efficiency of photodecomposition of the HbCO in the blood. The obtained results can be used in the clinical phototherapy practice for effective treatment of CO poisoning.
{"title":"Estimation of the quantum efficiency of the photodissociation of HbO2 and HbCO","authors":"A. Gisbrecht, S. Mamilov, S. S. Esman, M. Asimov","doi":"10.1117/12.2261829","DOIUrl":"https://doi.org/10.1117/12.2261829","url":null,"abstract":"The paper presents our results on the study of the efficiency of inter-fractional changes in hemoglobin molecules depending on the laser radiation parameters. The evaluation of the quantum efficiency of light interaction in vivo with oxyhemoglobin (HbO2) and carboxyhemoglobin (HbCO) in the blood at wavelengths for 525 and 605 nm is presented. The photodissociation yield of 11% for HbO2 and 79% for HbCO are measured at the wavelength of 525 nm and 10 % for HbO2 and 76 % for HbCO at a wavelength of 605 nm. Thus, the quantum yield of photodissociation of the HbCO is considerably higher, which ensures high efficiency of photodecomposition of the HbCO in the blood. The obtained results can be used in the clinical phototherapy practice for effective treatment of CO poisoning.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131354186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Nikov, N. Nedyalkov, P. Atanasov, D. Karashanova
Fabrication of silver nanoparticle colloids using nanosecond pulsed laser ablation in liquid is studied. Laser ablations of silver target in chloroform, toluene and ethanol were performed to prepare different nanosize metal colloids. Both fundamental wavelength (1064 nm) and second harmonic (532 nm) of Nd: YAG laser system were used. The influence of the laser wavelength on the morphology, size distribution, shape and optical properties of the produced nanoparticles was studied by transmission electron microscopy (TEM) and UV-Visible absorption measurements. The selected area electron diffraction (SAED) was employed to identify the phase composition of the formed nanostructures. Nanoparticles in chloroform show a large difference in the mean size at both laser wavelengths used — 3,2 nm at 1064 nm and 43 nm at 532 nm. The laser ablation in toluene at both laser wavelength used results in formation of nanoparticles with relatively small mean size (up to 5 nm). Silver nanoparticles in ethanol produced by 1064 nm show mean size of 20 nm while those prepared by second harmonic — 45 nm. The nanoparticles produced by ablation in chloroform and toluene do not show surface plasmon resonance (SPR) absorption in their optical absorption spectra. In contrast the colloidal nanoparticles produced by laser ablation in ethanol exhibit plasmon behavior. The presented method is an alternative to the widely used chemical methods for the preparation of colloidal solutions with certain characteristics enabling their application in the printed electronics to obtain the conductive tracks, and also for the preparation of nanostructured surfaces for surface-enhanced Raman spectroscopy (SERS).
{"title":"Characterization of colloidal silver nanostructures produced by pulsed laser ablation in different liquids","authors":"R. Nikov, N. Nedyalkov, P. Atanasov, D. Karashanova","doi":"10.1117/12.2261813","DOIUrl":"https://doi.org/10.1117/12.2261813","url":null,"abstract":"Fabrication of silver nanoparticle colloids using nanosecond pulsed laser ablation in liquid is studied. Laser ablations of silver target in chloroform, toluene and ethanol were performed to prepare different nanosize metal colloids. Both fundamental wavelength (1064 nm) and second harmonic (532 nm) of Nd: YAG laser system were used. The influence of the laser wavelength on the morphology, size distribution, shape and optical properties of the produced nanoparticles was studied by transmission electron microscopy (TEM) and UV-Visible absorption measurements. The selected area electron diffraction (SAED) was employed to identify the phase composition of the formed nanostructures. Nanoparticles in chloroform show a large difference in the mean size at both laser wavelengths used — 3,2 nm at 1064 nm and 43 nm at 532 nm. The laser ablation in toluene at both laser wavelength used results in formation of nanoparticles with relatively small mean size (up to 5 nm). Silver nanoparticles in ethanol produced by 1064 nm show mean size of 20 nm while those prepared by second harmonic — 45 nm. The nanoparticles produced by ablation in chloroform and toluene do not show surface plasmon resonance (SPR) absorption in their optical absorption spectra. In contrast the colloidal nanoparticles produced by laser ablation in ethanol exhibit plasmon behavior. The presented method is an alternative to the widely used chemical methods for the preparation of colloidal solutions with certain characteristics enabling their application in the printed electronics to obtain the conductive tracks, and also for the preparation of nanostructured surfaces for surface-enhanced Raman spectroscopy (SERS).","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123710496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Genova, E. Borisova, N. Penkov, B. Vladimirov, I. Terziev, A. Zhelyazkova, L. Avramov
The wide spread of colorectal cancer and high mortality rate among the patients, brings it to a level of high public health concern. Implementation of standard endoscopic surveillance proves to be effective for reduction of colorectal cancer patients’ mortality, since its early diagnosis allows eradication of the disease prior to invasive cancer development, but its application in common clinical practice is still limited. Therefore the development of complimentary diagnostic techniques of the standard white-light endoscopy is on high demand. The non-invasive and highly informative nature of the fluorescence spectroscopy allow to use it as the most realistic prospect of an add-on “red flag” technique for early endoscopy detection of colorectal cancer. Synchronous fluorescence spectroscopy (SFS) is a steady-state approach that is used for evaluation of specific fluorescence characteristics of cancerous colorectal tissues in our studies. The feasibility of polarization fluorescence technique to enhance the contrast between normal and cancerous tissues was investigated as well. Additional linear polarizing optics was used on the way of the excitation and emission fluorescence light beams. The polarizing effects were investigated in parallel and perpendicular linear polarization modes respectively. The excitation applied was in the region of 280 – 440 nm, with 10 nm scanning step, and the fluorescence emission was detected in the region of 300 – 800 nm. Our previous experience with SFS technique showed its great potential for accurate, highly sensitive and specific discrimination between cancerous and normal colorectal tissue. Since one of the major sources of endogenous fluorescence with diagnostic meaning is the structural protein — collagen, which is characterized with high anisotropy, we’ve expected and observed an enhancement of the spectral differences between cancerous and normal colorectal tissue, which could be beneficial for the colorectal tumour’ diagnostics using SFS.
{"title":"Autofluorescence polarization spectroscopy of cancerous and normal colorectal tissues","authors":"T. Genova, E. Borisova, N. Penkov, B. Vladimirov, I. Terziev, A. Zhelyazkova, L. Avramov","doi":"10.1117/12.2264453","DOIUrl":"https://doi.org/10.1117/12.2264453","url":null,"abstract":"The wide spread of colorectal cancer and high mortality rate among the patients, brings it to a level of high public health concern. Implementation of standard endoscopic surveillance proves to be effective for reduction of colorectal cancer patients’ mortality, since its early diagnosis allows eradication of the disease prior to invasive cancer development, but its application in common clinical practice is still limited. Therefore the development of complimentary diagnostic techniques of the standard white-light endoscopy is on high demand. The non-invasive and highly informative nature of the fluorescence spectroscopy allow to use it as the most realistic prospect of an add-on “red flag” technique for early endoscopy detection of colorectal cancer. Synchronous fluorescence spectroscopy (SFS) is a steady-state approach that is used for evaluation of specific fluorescence characteristics of cancerous colorectal tissues in our studies. The feasibility of polarization fluorescence technique to enhance the contrast between normal and cancerous tissues was investigated as well. Additional linear polarizing optics was used on the way of the excitation and emission fluorescence light beams. The polarizing effects were investigated in parallel and perpendicular linear polarization modes respectively. The excitation applied was in the region of 280 – 440 nm, with 10 nm scanning step, and the fluorescence emission was detected in the region of 300 – 800 nm. Our previous experience with SFS technique showed its great potential for accurate, highly sensitive and specific discrimination between cancerous and normal colorectal tissue. Since one of the major sources of endogenous fluorescence with diagnostic meaning is the structural protein — collagen, which is characterized with high anisotropy, we’ve expected and observed an enhancement of the spectral differences between cancerous and normal colorectal tissue, which could be beneficial for the colorectal tumour’ diagnostics using SFS.","PeriodicalId":355156,"journal":{"name":"International School on Quantum Electronics: Laser Physics and Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115480747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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