紫外激光诱导胃癌组织自体荧光的研究

本文测量了紫外激光（３０８ｎｍ）激发诱导正常组织和胃癌组织３１５ｎｍ－６００ｎｍ波段的自体荧光，发现胃癌组织在此荧光光谱不同于正常组织的荧光光谱。根据两者４的区别，可以把胃癌组织从正常组织中区分出来，这为诊断胃癌提供了一个新的思路。     

激光诱发荧光用于结肠肿瘤早期诊断

激光诱导荧光法（ＬａｓｅｒＩｎｄｕｃｅｄ Ｆｌｕｏｒｅｓｃｅｎｃｅ ＬＩＦ）利用生物组织的自体荧光特性判断组织性质,能实时、无损地提供组织信息,从而区分正常与病变组织。本文采用固体可调谐激光器Ｃｒ：ＬｉＣＡＦ作为激发光源,在３６０ｎｍ ～４１０ｎｍ 波段范围选择多种波长对结肠癌和结肠正常组织标本进行ＬＩＦ测试,找出了能诱导结肠正常组织与癌变组织产生最大荧光光谱差异的最佳激发波长,并对３１ 组正常组织与病变组织标本进行测式,结果表明结肠正常组织与癌变组织自体荧光光谱存在明显差异。     

紫外激光诱导CAG组织的自体荧光的研究

本文首次用紫外激光诱导组织的自体荧光法，测量了慢性萎缩性胃炎组织和正常组织３１５ｎｍ－６００ｎｍ波段的自体荧光，实验结果表明，ＣＡＧ组织的荧光光谱不同于正常组的荧光光谱。根据它们之间的区别，有可能从正常组织中区出ＣＡＧ组织，为诊断ＣＡＧ和胃癌提供有力依据。     

离体乳腺正常组织、良性瘤及癌的自体荧光光谱

用４８８ｎｍ氩离子激光作激发光源,对乳腺正常组织、良性瘤及癌的离体组织标本进行了激光诱导组织自体荧光光谱分析。结果表明,三种不同性质的乳腺组织的自体荧光光谱之间有较明显的差异。这些光谱差异对于癌症的光谱诊断研究有一定的参考价值。     

结肠肿瘤组织自体荧光光谱体内测试

用氮分子激光（３３７ｎｍ）对８９例结肠镜检测异常病例进行体内激光诱发自体荧光测试,得到了与体外测试一致的结果。选取多个特征参数进行结肠正常组织与癌变组织的自体荧光光谱比较,找到了癌变组织区别于正常组织的光谱特征。据此得出结论：结肠正常组织与癌变组织自体荧光光谱存在明显差异,可以作为一种无创伤内镜下恶性病变的筛选分析方法,在指导内镜活检方面具有良好的应用前景。     

370nm激光在结肠癌变早期诊断上的应用研究

本文利用Ｃｒ：ＬｉＣＡＦ可调谐激光器,经ＢＢＯ晶体倍频,获得了８ｍＪ、３４ｎｓ、３７０ｎｍ的巨脉冲激光;并利用３７０ｎｍ激光激发离体结肠癌组织和正常组织进行组织的自体荧光实验,并作了对比和分析,获得了对结肠癌变的早期诊断的很有价值的荧光光谱。     

氮激光诱导荧光光谱法对动脉粥样硬化斑块的诊断研究

采用波长为337nm的N_2分子激光作光源,利用激光诱导荧光光谱法测量血管组织的自荧光,选择波长为390nm和476nm处的荧光强度比值可以很好地鉴别动脉血管的正常组织和粥样硬化斑块,阈值为1.25。     

308nm激光诱导动物血管荧光光谱的观测

利用XeCl准分子激光辐照兔、狗动物主动脉及多种器官,观测到近紫外至可见波段连续发射的荧光光谱,荧光在380nm及450nm处有二个极值,测得正常主动脉及主动脉斑块二极值强度之比分别为I_(380)/I_(450)=1.05±0.07及1.32±0.10。     

利用光谱和时间分辨的多光子显微技术识别人体冠状动脉粥样硬化斑块

采用光谱和时间分辨的多光子显微技术对8例未染色的人体冠状动脉组织进行研究,根据荧光光谱分离出冠状动脉内膜中的弹性纤维和胶原纤维,并计算粥样硬化病变与非病变冠状动脉内膜中两种纤维信号的比值,从而获得胶原纤维和弹性纤维相对含量的变化。采用荧光寿命评估了冠状动脉粥样硬化组织中弹性纤维生化特性的变化,结果显示,冠状动脉硬化斑块区域具有较短的平均荧光寿命。光谱和时间分辨的多光子显微技术能有效识别冠状动脉粥样硬化斑块,有望成为研究冠状动脉粥样硬化病变的新方法。     

激光诱导血清荧光诊断肝癌初探

本文采用激光（波长为５１４．５ｎｍ）诱导血清荧光的方法，测量了肝癌病人，肝硬变病人，和肝肿瘤切除后病人血清以及正常人血清的自体荧光光谱，发现肝癌病人血清的光谱轮廓和其他三者有本质区别，并初步认为这种区别可以作为诊断肝癌的依据。     

Laser ablation of atherosclerotic blood vessel tissue under variousirradiation conditions

A quantitative analysis is presented of the destruction of normal wall and atherosclerotic plaque areas of blood vessels by laser radiation. Threshold laser radiant exposure values were measured experimentally in vitro, along with the ablation efficiency for various laser wavelengths and irradiation conditions. Correlations were found between the ablation efficiency and fluence thresholds on the one hand and the optical properties of the blood vessel tissues on the other. Fibrous plaque was demonstrated to be selectively destroyed by the second-harmonic output from a pulsed Nd:YAG laser at lambda = 532 nm.     

人肝组织病变及热凝固导致组织光学特性的变化

研究了人肝的病变及热凝固的肝组织对532 nm和1064 nm激光的光学特性的变化。实验采用双积分球测量系统以及运用生物组织的反向倍增(IAD)光学模型。结果表明,正常肝组织对532 nm和1064 nm的吸收系数显著地较肝肿瘤组织要大;正常肝和肝肿瘤组织热凝固后对532 nm的吸收系数都显著地增大,正常肝组织热凝固后对1064 nm的吸收系数显著减小。而肝肿瘤组织热凝固后对1064 nm的吸收系数却显著地增大。正常肝组织对532 nm和1064 nm的散射系数都显著地较肝肿瘤组织要小,正常肝和肝肿瘤组织热凝固后散射系数都显著地增大。正常肝组织对532 nm和1064 nm的各向异性因子都明显地较肝肿瘤组织要大,正常肝和肝肿瘤组织热凝固后其各向异性因子都明显地减小。     

Preferential ablation of calcified arterial plaque with laser-induced plasmas

Laser endarterectomy, a promising new method of reopening stenotic or occluded arteries, has been limited by difficulties in ablating calcified plaque. This study demonstrates that pulsed, visible laser radiation (482 nm, 1 μs duration, 40-80 mJ/pulse) can ablate calcified plaque at intensities (50 MW/cm²) that are readily transmit, ted down flexible (320 μm diameter) optical fibers and at fluences which are below the threshold for ablating normal artery. The ablative process is characterized by a loud snapping sound, a luminescent plume, ejection of fine debris, and an ablation efficiency as high as 10 mg/J, suggesting that removal of material occurs primarily by formation of a plasma and fracturing of the plaque, rather than by thermal vaporization. The presence of a plasma associated with ablation of calcified plaque was documented by emission spectrum measurements.     

Development and evaluation of spectral classification algorithmsfor fluorescence guided laser angioplasty

Laser angioplasty, or the ablation of atherosclerotic plaque using laser energy, has tremendous potential to expand the scope of nonsurgical treatment of obstructive vascular disease. Clinical laser angioplasty, however, has been hindered by an unacceptable risk of vessel perforation. Laser-induced fluorescence spectroscopy can discriminate atherosclerotic from normal artery and may therefore be capable of guiding selective plaque ablation. To assess the feasibility of utilizing spectral information to discriminate arterial tissue type, several classification algorithms were developed and evaluated. Arterial fluorescence spectra from 350 to 700 nm were obtained from 100 human aortic specimens. Seven spectral classification algorithms were developed with the following techniques: multivariate linear regression, stepwise multivariate linear regression, principal components analysis, decision plane analysis, Bayes decision theory, principal peak ratio, and spectral width. The classification ability of each algorithm was evaluated by its application to the training set and to a validation set containing 82 additional spectra. All seven spectral classification algorithms prospectively classified atherosclerotic and normal aorta with an accuracy greater than 80 percent (range: 82-96 percent). Laser angioplasty systems incorporating spectral classification algorithms may therefore be capable of detection and selective ablation of atherosclerotic plaque.     

808 nm近红外激光辐照三种不同的离体人组织的光传输特性

采用双积分球系统和光辐射测量技术的基本原理以及运用生物组织的光学模型 ,研究了 80 8nm激光及其线偏振激光辐照人正常小肠、人正常膀胱和人膀胱癌组织的光学特性。结果表明 ,Kubelka Munk二流模型下 ,人正常膀胱组织与人膀胱癌组织对 80 8nm激光及其线偏振激光的各个光学特性参量均有非常显著的差异 (P <0 0 1)。人正常膀胱组织对 80 8nm激光及其线偏振激光的光学特性参量均有差异 ,其中吸收系数和有效衰减系数有明显差异。人膀胱癌组织对 80 8nm激光及其线偏振激光的光学特性参量均没有显著性差异 (P >0 0 5 ) ,表明人膀胱癌组织对 80 8nm线偏振激光的退偏振较大。人正常小肠组织对 80 8nm激光及其线偏振激光的光学特性参量均有显著性差异 (P <0 0 1) ,表明人正常小肠组织对 80 8nm线偏振激光的退偏振较小。在Kubelka Munk二流模型下 ,80 8nm激光及其线偏振激光辐照三种人组织的光强分布均有明显的不同     

Anticompetition Between Laser Modes in Quantum-Dot Laser

Anticompetition behavior is observed in a InAs quantum-dot (QD) laser with external wavelength control. Unlike the competition behavior observed in other QD lasers, in this experiment, the laser emission induced by external feedback at the ground state wavelength improves the excited-state emission at 1170 nm by 13 dB. Such an anticompetition phenomenon is most obvious as the feedback wavelength differs from 1250 nm, the original lasing wavelength, by 15 nm. This anticompetition behavior is explained by the sharing of QDs between the laser emission induced by the feedback and the original laser oscillation     

激光二极管抽运复合腔和频连续波589 nm激光器

报道了一种利用复合腔进行腔内和频的589nm激光器.激光器由两个子谐振腔组成.在两个子谐振腔中,分别利用两个激光二极管(LD)抽运Nd∶YAG晶体和Nd∶YVO4晶体,并分别选择1319 nm波长(对应Nd∶YAG晶体的4F3/2→4I13/2跃迁)与1064 nm波长(对应Nd∶YVO4晶体的4F3/2→4I11/2跃迁)振荡进行和频.通过谐振腔的优化设计,实现了腔内两个波长较好的模式与增益匹配.在两个子腔的交叠部分,利用BiB3O6(BIBO)晶体Ⅰ类临界相位匹配进行腔内和频,得到和频激光输出.当Nd∶YAG与Nd∶YVO4晶体上抽运功率分别为750 mW和600 mW时,获得了24 mW,589 nm黄橙激光输出.该输出激光光束质量好、噪声低.     

A Micro Blue-violet Laser by Frequency Doubling of Semiconductor Laser

In this paper, a micro blue-violet laser by frequency doubling of a semiconductor laser with a new nonlinear organometallic complex cadmium mercury thiocyanate crystal (CMTC) is reported. At room temperature, the blue-violet laser output of 11.8 mW at 404 nm and the conversion4efficiency of the second harmonic generation (SHG) of 0. 60% were obtained with a 1. 98 W, 808 nm semiconductor laser and a 4 mm crystal.     

微结构光纤正常色散区飞秒激光脉冲传输光谱展宽的功率饱和效应

利用自制的微结构光纤进行了飞秒激光脉冲传输实验,输入激光脉冲的中心波长为800 nm,位于微结构光纤的正常色散区。随着输入激光脉冲的平均功率从220 mW逐渐增大到300 mW,输出光谱同时向长波和短波方向展宽,光谱中的反斯托克斯线对应的能量逐渐占据主导地位。平均功率达到280 mW时,光谱的展宽范围不再增大,显示出了一种功率饱和效应。在微结构光纤的正常色散区实现了波长从560~960 nm的20 dB展宽谱。