Laser Physics Letters最新文献_第10页

Machine-learning-based mapping of blood oxygen saturation from dual-wavelength optoacoustic measurements 基于机器学习的双波长光声测量血氧饱和度绘图

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-19 DOI: 10.1088/1612-202x/ad1aa4

D A Kurakina, M Yu Kirillin, A V Khilov, V V Perekatova

{"title":"Machine-learning-based mapping of blood oxygen saturation from dual-wavelength optoacoustic measurements","authors":"D A Kurakina, M Yu Kirillin, A V Khilov, V V Perekatova","doi":"10.1088/1612-202x/ad1aa4","DOIUrl":"https://doi.org/10.1088/1612-202x/ad1aa4","url":null,"abstract":"We developed a novel machine-learning-based algorithm based on a gradient boosting regressor for three-dimensional pixel-by-pixel mapping of blood oxygen saturation based on dual-wavelength optoacoustic data. Algorithm training was performed on <italic toggle=\"yes\">in silico</italic> data produced from Monte-Carlo-generated absorbed light energy distributions in tissue-like vascularized media for probing wavelengths of 532 and 1064 nm and the empirical instrumental function of the optoacoustic imaging setup with further validation of the independent <italic toggle=\"yes\">in silico</italic> data. <italic toggle=\"yes\">In vivo</italic> optoacoustic data for rabbit-ear vasculature was employed as a testing dataset. The developed algorithm allowed <italic toggle=\"yes\">in vivo</italic> blood oxygen saturation mapping and showed clear differences in blood oxygen saturation values in veins at 15 °C and 43 °C due to functional arteriovenous anastomoses. These results indicated that dual-wavelength optoacoustic imaging could serve as a cost-effective alternative to complicated multiwavelength quantitative optoacoustic imaging.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139510160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantum coherence and Rényi mutual information in Heisenberg XYZ system under non-uniform field 非均匀场下海森堡 XYZ 系统的量子相干性和雷尼互信息

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-18 DOI: 10.1088/1612-202x/ad1aa3

Biaoliang Ye, Zhanjun Zhang

引用次数: 0

Intracavity heterodyne laser interferometry. Studies of the features of optical Kerr effect in the atmosphere 腔内外差激光干涉仪。大气中光学克尔效应特征的研究

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-18 DOI: 10.1088/1612-202x/ad1aa9

V M Gelikonov, M A Novikov

{"title":"Intracavity heterodyne laser interferometry. Studies of the features of optical Kerr effect in the atmosphere","authors":"V M Gelikonov, M A Novikov","doi":"10.1088/1612-202x/ad1aa9","DOIUrl":"https://doi.org/10.1088/1612-202x/ad1aa9","url":null,"abstract":"The features of high-sensitivity frequency and phase measurements in a He–Ne gas laser at a wavelength of 0.63 <italic toggle=\"yes\">μ</italic>m are considered. The single-frequency mode of this laser with a large excess of the lasing threshold is implemented due to longitudinal mode selection using an ultra-thin nickel metal film placed in the standing field node of the cavity. With such an excess of the lasing threshold, the natural linewidth component is very small (∼10−3Hz), which was determined from the heterodyne method of measuring natural fluctuations of lasing frequency. This method can be used in combination with the multibeam intracavity interferometry for measuring phase modulation at a level of 10−9 rad Hz−1/2. To demonstrate the capabilities of the method, the electro-optical Kerr effect in air at atmospheric pressure in linearly polarized light was studied separately for extraordinary and ordinary waves. The Kerr and the Havelock constants were measured. A deviation from a purely quadratic dependence determined by the fourth power of the amplitude of a low-frequency electric field was found. A possible explanation of the detected deviation from the Kerr effect is the electrostriction.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139508180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Non-stationary quasi-classical states of a charged particle in a strong magnetic field under conditions of the dissipative medium 耗散介质条件下强磁场中带电粒子的非稳态准经典状态

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-18 DOI: 10.1088/1612-202x/ad1cdd

S V Sazonov

引用次数: 0

Comparative analytical and numerical investigation of the plasma density in atmospheric air generated by nanosecond laser pulses 纳秒激光脉冲在大气中产生的等离子体密度的分析和数值比较研究

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-18 DOI: 10.1088/1612-202x/ad1cd9

H Delibašić Marković, K Kaleris, N A Papadogiannis, V Petrović

{"title":"Comparative analytical and numerical investigation of the plasma density in atmospheric air generated by nanosecond laser pulses","authors":"H Delibašić Marković, K Kaleris, N A Papadogiannis, V Petrović","doi":"10.1088/1612-202x/ad1cd9","DOIUrl":"https://doi.org/10.1088/1612-202x/ad1cd9","url":null,"abstract":"Energy deposition via laser-induced breakdown (LIB) in gases or other media and its accompanying secondary light and sound radiative processes are nowadays increasingly deployed in scientific and technological applications. The modeling and control of the breakdown and radiative processes occurring by the interactions of the free electrons with the heavy particles in the partially ionized medium, requires precise spatio-temporal description of the generated free electron density. This work presents an analysis of a free electron rate model describing the free electron density in air plasmas produced by nanosecond laser pulses. The model accounts for multiphoton and cascade ionization, and for electron diffusion, recombination, and attachment. A closed-form expression of the rate model is derived and validated by comparison with experimentally validated numerical solutions, showing very good agreement in a wide range of parameters. Simulation results are presented for different laser pulses and focal spot sizes and analysis is carried out regarding the dependence of the air plasma on the various laser radiation parameters. The presented approach is particularly useful for complex multi-scale models calculating the electron and ion temperature evolution, the thermoelastic expansion and the shock-wave following LIB of gases.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139508134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The influence of heating on the appearance of polarization singularities during the self-action of a Gaussian beam in the isotropic phase of a nematic liquid crystal in the pre-transition temperature region 向列液晶各向同性相中的高斯光束在转变前温度区域的自作用过程中加热对偏振奇点出现的影响

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-12 DOI: 10.1088/1612-202x/ad1aa6

G M Shishkov, K S Grigoriev, V A Makarov

{"title":"The influence of heating on the appearance of polarization singularities during the self-action of a Gaussian beam in the isotropic phase of a nematic liquid crystal in the pre-transition temperature region","authors":"G M Shishkov, K S Grigoriev, V A Makarov","doi":"10.1088/1612-202x/ad1aa6","DOIUrl":"https://doi.org/10.1088/1612-202x/ad1aa6","url":null,"abstract":"Heating of the medium occurs during the self-action of elliptically polarized light in the isotropic phase of a nematic liquid crystal near the transition temperature to the mesophase. We studied the influence of heating of the medium, on the propagation modes of laser radiation and the dynamics of the formation of singularity lines of circular polarization in the cross sections of the beam, which is closely related to the multifocal structure of the electric field. It is shown that an increase in the incident radiation intensity leads to a decrease in distance from the front end of the cylindrical cuvette to the beam cross section, containing the primary (brightest and most stable) polarization singularity lines, as well as in the radius of the circle they form. The range of parameters of the incident radiation and medium at which the multifocal structure of the electric field of the propagating beam is formed, as well as the intensity threshold values at which it appears, decreases with the growth of the thermal conductivity coefficient of the liquid crystal.","PeriodicalId":17940,"journal":{"name":"Laser Physics Letters","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139508171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Efficient noiseless linear amplification protocol for single-photon state using imperfect auxiliary photon source 使用不完美辅助光子源的高效无噪声单光子状态线性放大协议

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-12 DOI: 10.1088/1612-202x/ad1aaa

Jing-Qiu Gu, Ya-Peng Feng, Ming-Ming Du, Wei Zhong, Yu-Bo Sheng, Lan Zhou

引用次数: 0

Mode-locked Yb:CALGO laser with high peak power sub-100 fs pulses at 26.9 MHz repetition rate 以 26.9 MHz 重复频率发出峰值功率低于 100 fs 脉冲的模式锁定 Yb:CALGO 激光器

IF 1.7 4区物理与天体物理

Laser Physics Letters Pub Date : 2024-01-11 DOI: 10.1088/1612-202x/ad1aa7

Md A R Reza, A Major

引用次数: 0

Effect of burst mode modulation ultrashort pulse laser on the laser processing transparent dielectrics 猝发模式调制超短脉冲激光器对激光加工透明电介质的影响