A New Organic Up-conversion Laser Dye HEASPS

A new organic dye, trans-4-[p-(N-hydroxyethyl-N-ethylamino)styryl]-N-methyl- pyridinium p-toluene sulfonate (HEASPS) has been synthesized and its structure has been determined. Pumped with a 1064 nm, 50 ps laser pulses, 0.05 mol/L HEASPS/DMF solution showed the two-photon pumped (TPP) output/input efficiency of 9.1% which is higher than that of known TPP laser dyes trans-4-[p-(N-hydroxyethyl-N-methylamino) styryl]-N-methylpyridinium iodide (ASPI) and trans-4-[p-(N-hydroxyethyl-N-methylamino) styryl]-N-methylpyridinium p-toluene sulfonate (HMASPS) at the same experimental conditions.

Photo-Physical Properties of Stilbine-3 (STB-3) Laser Dyes Embedded in Sol-Gel Glasses

Solid-state tunable dye laser materials developed by incorporation of stable laser dye molecules into solid host matrices like polymers, organically modified silicates (ORMOSILS) and porous sol-gel glasses. These materials have technical advantages such as compactness, better manageability and suitability for field measurement. The recent research work with highly porous sol-gel glasses having good transparency in UV-Near UV region used as solid host for solid-state dye laser materials has attracted a great deal of attention because of its high potential utility than polymers. Two different procedure’s are used for incorpoerating the Stilbine-3 (STB-3) laser dyes into porous sol-gel matrices such as dope or dip methods. In dope method dye is mixed at the sol state and drying is carried out afterward;while in dip method matrix is first prepared and the matrix is dipped in desired dye solution. After preparation of these dye embedded sol-gel glasses we studied their spectroscopic properties of using absorption and fluorescence spectroscopy. Along with spectroscopy properties, the studies for longevity or the shelf life and lasing action of these materials were carried out. Laser dye STB-3 incorporated in sol-gel glass samples shows the same result as in methanolic solution.

Synthesis and Characterization of a New Organic Up-conversion Laser Dye HMASPS

A new organic dye, trans-4-[4'-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium p-toluene sulfonate (HMASPS) has been synthesized and its structure has been determined. Pumped with a 1064 nm, 50 ps laser pulses, 0.05 mol/L HMASPS/DMF solution showed the two-photon pumped (TPP) output/input efficiency of 8.4% which is higher than that of trans-4-[p-(N-hydroxyethyl-N-methylamino) styryl]-N-methylpyridinium iodide (ASPI)(1) at the same pump level.

Comparative Study of Coumarin-120 (C-120) and Stilbine-3 (STB-3) Laser Dyes Doped in Sol-Gel Glasses

In 1967 the first work in solid state dye laser was performed by doping rhodamine dyes in Polymethylmethacrylate (PMMA) materials. Since then some materials like various types of polymers, co-polymers, poly composite glasses have been used as host matrices for doping different laser dyes. Polymers suffer from limited mechanical and thermal stability. Hence glasses can be the alternative hosts. However, because of high processing temperature leading to permanent destruction of dye molecules, the conventional glass preparation technique is not suitable for the introduction of organic laser dyes. This difficulty can be overcome by introducing the laser dye molecules in sol-gel glass which is prepared at low temperature. Recent work with sol-gel glasses shows that these glasses may prove to be better materials compared to polymeric materials because glasses being hard, best optically transparency in Near UV-UV and Visible region and show better photostability. In this research work we reported, comparative study of the photophysical properties of Coumarin-120 (C-120) belonging to 7-aminocoumarin family having two hydrogen atoms attached to the N atom at the 7-position, with Stilbene-3 (STB-3) in three types of HCl catalyzed SiO2 sol-gel matrices prepared by Method I, Method II and Method III respectively.

Excited State Interaction of Laser Dyes and Silver Nanoparticles in Different Media

Quenching the fluorescence of the dyes 3-(4’-dimethylaminophenyl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (DMAPrP), 3- (4’-dimethylaminophenyl)-1-(2-furanyl)prop-2-en-1-one (DMAFP) and 3-(4’-dimethylaminophenyl)-1-(2-thienyl)prop- 2-en-1-one (DMATP) has been investigated in the presence of silver cation and silver nanoparticles in different media. The results of the quenching experiments were analyzed using Stern-Volmer equation. Quenching the fluorescence of the dyes decreased with increasing medium viscosity. The Stern-Volmer constant (KSV) values in the absence and presence of ethylene glycol show that the quenching efficiencies decrease as the medium viscosity increases indicating that the quenching process is a diffusion-controlled process, and this is consistent with a dynamic-type quenching.

Effect of Medium Acidity and Photostability of 3-（4-Dimethyl- amino-phenyl）-l-（2,5-dimethyl-thiophen-3-yl）-propenone （DDTP）： A New Green Emitting Laser Dye

On the line of a previous work on the spectral properties of some of heteroaryl chalcone, the effect of medium acidity and photoreactivity of 3-（4-dimethylamino-phenyl）-l-（2,5-dimethyl-thiophen-3-yl）-propenone （DDTP） has been investigated in dimethylformamide and in chloromethane solvents such as methylenechloride, chloroform and carbon tetrachloride. The dye solution （ca. 5×10^-4 mol·L^-1 in DMF） gives a good laser emission in the range 470 --560 nm with emission maximum at 515 nm upon pumping by nitrogen laser （λex=337.1 nm）. The laser parameters such as gain coefficient （a）, emission cross section （Cre） and half life energy （E1/2） at maximum laser emission are also determined.

Medium performance effect on the high output energy from a xenon lamp-pumped pyrromethene-567 solid-state dye laser

In order to obtain a high output energy from a xenon lamp-pumped solid-state dye laser, homogeneities of laser mediums and flatnesses of medium faces with different processing treatments are discussed in the paper. The mediums without aging treatment, which are prepared by using a prepolymer process and have diamond-machined end faces to produce the required optical finish, give a highest laser output of 281.9 mJ with 0.215% slope efficiency at 2.0x 10^-4 mol/L. The best medium lifetime is 21 shots to 50% of original output equating 74.6 k J/liter.

PM567-Doped solid dye lasers based on PMMA

Polymers are a kind of attractive hosts for laser dyes due to their high transparency in both pumping and lasing ranges and superior optical homogeneity. In this paper solid dye samples based on polymethyl methacrylate （PMMA） doped with different concentrations of 1, 3, 5, 7, 8 -pentamethyl-2, 6-diethylpyrromethene-BF2 （PM567） are prepared. The absorption, fluorescence and lasing spectra of the samples are obtained. Wide absorption and fluorescence bands are obtained and a red shift of the maxima of the lasing emission spectra is observed. With the second-harmonic generation of Q-switched Nd：YAC laser （532 nm, -20 ns） pumping the samples longitudinally, the slope efficiencies of the samples are obtained. There is an optimal dye concentration for the highest slope efficiency when the pumping energy is lower than some typical value （-250 mJ）, and the highest slope efficiency 35.6% is obtained in the sample with a dye concentration of 2 × 10^-4 mol/L. Pumping the samples at a rate of 10Hz with a pulse energy as high as 200 mJ （the fluence is 0.2 J/cm^2）, the output energy drops to one-half of its initial value after approximate 15500 pulses and the normalized photostability is 5.17CJ/mol. A kind of solid dye laser which could have some applications is built.

Characteristics of xenon-lamp pumped pyrromethene 567-doped dye laser based on polymethylmethacrylater

The solid-state medium containing pyrromethene 567 （PM567） in a polymethylmethacrylate polymer host is shown to lase under the flash lamp excitation. The experimental setup is an ordinary industrial product without special design. The bulk transmission losses, the output energy, and the other lasing properties are compared. The medium with the lowest transmission loss, measured to be 0.392 %/cm at 633 nm, gives a laser output of 130 mJ with a slope efficiency of 0.082%.

Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet

Laser action in methyl methacrylate （MMA） co-doped with sulforhodamine B and crystal violet dyes was investi- gated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd：YAG laser. Distributed feedback dye laser （DFDL） action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor-donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor-donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

FLASHLAMP- PUMPED PULSED DYE LASER IN TREATMENT OF PORT- WINE STAINS

To assess the effectiveness of the flashlamp- pumped pulsed dye laser (Photogeneca V, Synosure Corp, Boston, United States) in the treatment of port- wine stains. Methods. One hundred and ninety- four consecutive patients with port- wine stains were treated with a flashlamp- pumped pulsed dye laser in Peking Union Medical College Hospital from January 1998 to August 1999. Results. Of 194 patients who completed treatment, 56.2％ had more than 60％ fading of the lesion and only 6.7％ had less than 20％ fading. An average of 3.6 treatments were needed to achieve more than 60％ fading. The response was better in children than in adults, although the difference was not significant. Pigmentary change (usually transient) occurred in 3.1％ of patients. Conclusions. This study confirms the efficacy of the flashlamp- pumped pulsed dye laser in the treatment of port- wine stains in children and adults.

Huge Recalcitrant Warts Treated with Pulse Dye Laser after Conventional Therapies and Others Destructive Physical Modalities Failed

Cutaneous infections with the human papilloma virus, despite being almost always asymptomatic, can induce slow-growing lesions knowed as warts that can remain subclinical for long periods of time. There are several therapeutical options namely keratolytics, retinoids, imiquimod, cryotherapy, electrosurgery, lasers and classic surgery, but none has antiviral effects. We describe the case of a patient with large warts located on the dorsal surface of the right hand, treated with cryotherapy, CO2 laser and topical imiquimod having either no clinical response or quick relapse. Treatment with PDL was started and after 13 sessions, the patient was without lesions, with a good cosmetic result and so far without relapse. This case report is relevant to us and deserves to be published because of the size of the lesions and the great response to PDL despite all the failures with the other treatments.

PULSBD DYE LASER THROMBOLYSIS IN VITRO AND ITS EFFECTS ON VASCULAR FUNCTION AND STRUCTURE IN VIVO

The purpose of the study is to evatuate the feasibility of pulsed dye laser(PDL)throm bolysis In vitro and the effect of PDL on vascular function and structure invivo.In vitro,fifty hum an throm biwere divided into laser treated group(n=35),irritation group(n=11),and controgroup(n=4).In the laser treated group thethrom biwere irradiated by PDL with 300 pulses at 100m J/pulse.No irradiation wasgiven to the throm bi in the irritation group,while the catheter was put to and frointo the throm bi for there times,Neither irradintion nor irritation was given to thethrom bi in the controlgroup.Sixteen healthy dogs were studied in vivo.Under theguidance of the guide-w ire PDL catheter was put into the left coronary arteries(n=16)from which PDL was em itted for 1380±60 pulses at 100m J/pulse,whereasthe rightcoronary srteries(n=16)which did not receieve PDL em ission were servedas irritation group.Then the PDL were irradiated directly to the right coronaryarterial wall in the irritation group without the guidance of the guide-wire.AfterPDL irradiation.the weight of the throm bi was reduced from 1.79±0.23g to0.61±0.12g while in the irritation group theweight of the throm biwas only reducedfrom 1.65±0.19 to 1.42±0.15g.In these two aroups the reduction of throm biweightwere 68%±6% and 15%±7% resoectively(P【0.001).No self-dissolution of thethrom bi occurred in the control group.The finding under the contrast phasem icroscope indicated 91% of the debris size were smaller than the size of redcells.In vivo study,coronary angiography showed that no changes in luminalduam eter of both groups.Nomechanicalor thermal in jury to the coronary arterieswas found excepta light irregularity of the intima.PDL Throm bolysis was effectivein vitro.There was no mechanicaldam age or therm al in jury to the vessels during theprocedure of intracoronary PDL irradiation in vivo.

CW-Dye Laser Spectrometer for Ultrahigh Resolution Spectroscopy: Design and Performance

This work is devoted to building-up of ultrahigh resolution cw-dye laser spectrometer system. This system used self-frequency-stabilized and temperature-compensated plano-confocal reference cavity. The one-way propagation is achieved using new construction of optical diode. The laser frequency selection and tuning is accomplished using Mach-Zehnder interferometer of free spectral range 42.5 GHz. In combination with computerized tunable radio frequency technique, this system is capable of a resolution of about ±1 KHz. Applications for measuring high lying, weakly occupied metastable states of free atoms (line 548.792 nm of V-51) are investigated to a high degree of accuracy. The results of the constants A and B of the hfs as measured by fluorescence spectroscopy show that A = 160.762 and B = -17.918, while the obtained results for the hfs constants A and B as measured by laser-RF double resonance technique give A = 160.9950 and B = -17.3358.

Early Pulsed Dye Laser Treatment for Infantile Hemangiomas: An Open Study for 50 Japanese Infancies

Infantile hemangiomas, occurring at birth or during the first weeks of life, are benign vascular tumors with an initial proliferative phase and a later involutional phase. The massive proliferation on the key regions and unpredicted regression may threaten?life. Thus, early management of infantile hemangiomas is necessary for affected infancies. Recent studies showed that propranolol for infantile hemangiomas had high efficacy for disappearance or reduction of infantile hemangiomas. However, a most recent study demonstrated existence of propranolol-resistant infantile hemangiomas. Therefore, we retrospectively evaluated efficacy of established early pulsed dye laser treatment for infantile hemangiomas in the 50 Japanese infancies which were applied in the period from 2000 to 2005, because our series included from the plaque subtype to the more proliferative tumor subtype. High efficacy in both subtypes suggests that early pulsed dye laser treatment can still be included as the first option for the mixed type of infantile hemangiomas and that pulsed dye laser treatment may be useful as the second line for the propranolol-resistant mixed type of infantile hemangiomas.

The Up-conversion Laser Properties of a Non-polar Organic Dye and the Influence of Solvents and Pumping Wavelengths

A non-polar organic dye, E, E-1, 4-bis[4＇-（N,N-dibutylamino）styryl]-2,5-dimethoxybenzene （DBASDMB）, has been synthesized and characterized, and its structure has been determined. Pumped with a 200fs pulse this dye showed the up-conversion laser properties. The influences of various organic solvents and different pumping wavelength on the laser properties have been demonstrated.

染料激光联合同位素32P贴敷治疗手术瘢痕的疗效

目的探讨染料激光联合同位素32P贴敷治疗手术瘢痕的疗效。方法选取2020年1月至2021年6月赣南医学院第一附属医院皮肤科收治的114例手术瘢痕患者作为研究对象,按照随机抽签法分为对照组与观察组,各57例。对照组给予染料激光治疗,观察组给予染料激光联合同位素32P贴敷治疗。比较两组临床疗效和治疗前后症状评分、血清学指标及治疗安全性。结果观察组治疗总有效率为92.98%,高于对照组的77.19%,差异有统计学意义(P<0.05)。治疗后,观察组瘙痒评分、视觉模拟评分法(VAS)、温哥华瘢痕量表(VSS)评分均低于对照组,差异有统计学意义(P<0.05)。治疗后,观察组血清转化生长因子-β1(TGF-β1)、血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)水平均低于对照组,差异有统计学意义(P<0.05)。两组不良反应发生率比较差异无统计学意义。结论染料激光联合同位素32P贴敷治疗手术瘢痕的疗效显著,能改善患者的皮肤瘙痒、疼痛症状及瘢痕状态,抑制血清生长因子水平,治疗安全性较高。

595 nm脉冲染料激光器治疗婴幼儿浅表血管瘤的临床疗效及影响因素分析

目的:回顾性研究Vbeam 595 nm脉冲染料激光器(PDL)治疗婴幼儿血管瘤(IHs)中期临床效果,分析探索其可能的影响因素。方法:收集2020年1月至2022年12月唐山市妇幼保健院行PDL治疗的219例IHs患儿,并至少随访6个月,分析治疗效果与月龄、血管瘤部位、厚度及治疗次数等之间的关系。结果:219例患儿总体中位月龄7个月,平均月龄(4~10)个月,总计219处病损。月龄、病损特征等一般资料在性别间差异无统计学意义(P>0.05)。治疗总体有效率92.7%,中位治疗次数3次,平均(2~4)次。男女性别间比较、治疗次数及治疗结局差异无统计学意义(P>0.05)。疗效差的6人,月龄13(8,19)个月;疗效一般的10人,月龄13(8,14)个月;疗效好的31人,月龄8(4,10)个月;疗效优的172人,月龄6(4,9)个月;不同疗效患儿间月龄差异具有统计学意义(Z=24.863,P<0.001),疗效优的患儿月龄较小。血管瘤患儿的治疗结局与其病变厚度、面积大小及治疗次数有相关性(r=-0.32、-0.46、-0.46,P<0.05),治疗有效主要集中在2~4次的治疗中。治疗引起的不良反应为皮肤红斑,总体半年后残留并发症率为5.48%。结论:595 nm PDL联合动态冷却装置(DCD)治疗为IHs提供了一种安全、有效的治疗方式,在早期对IHs进行干预,可以提高治疗效果,减少治疗疗程,从而进一步减少相应并发症可能。