<title>Usage of an electrically controlled photomask for dry microlithography by femtosecond visible laser radiation</title>

ABSTRACTAblation and etching of the surface of polymethyl methacrylate (=PMMA) by pulses of 248 nm laser radiation ∼20 ns full width at half maximum (FWHM) have been probed by pulses of visible laser radiation (596 nm; < 1 ns FWHM). The results were recorded photographically in real time with a set time delay between the 248 nm ablation pulse and the 596 nm probe pulse. Modification of the surface structure of the polymer at a fluence ∼ 3 J/cm2 is first visible at 12 ns and appears to be complete in ∼ 60 ns. The first manifestation of the ablation does not occur until the UV pulse is over and consists of a nearly transparent shock-wave that has an initial velocity of 6 ∼ 104 cm/sec. Solid material from the ablated zone begins to leave the surface at ∼150 - 200 ns and reaches a maximum in intensity at 6 µs, continuing for ∼ 20 µs. The average velocity of the solid material, which is probably a low molecular weight polymer of PMMA, is 1.5 ∼ 104 cm/sec. The conclusion to be drawn from the present work is that the signal measured by photoacoustic detectors does not coincide with the bulk of the material leaving the surface.

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Effects of Low-Intensity Polarized Visible Laser Radiation on Skin Burns: A Light Microscopy Study

Journal of Clinical Laser Medicine & Surgery ◽

10.1089/104454704773660994 ◽

2004 ◽

Vol 22 (1) ◽

pp. 59-66 ◽

Cited By ~ 65

Author(s):

Martha Simões Ribeiro ◽

Daniela De Fátima Teixeira Da Silva ◽

Carlos Eugênio Nabuco De Araújo ◽

Sérgio Ferreira De Oliveira ◽

Cleusa Maria Raspantini Pelegrini ◽

...

Keyword(s):

Laser Radiation ◽

Light Microscopy ◽

Microscopy Study ◽

Low Intensity ◽

Visible Laser

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Attenuation of Dictyocaulus filaria larvae by visible Laser radiation : 2- In vivo study

The Iraqi Journal of Veterinary Medicine ◽

10.30539/ijvm.v24i2.1165 ◽

2000 ◽

Vol 24 (2) ◽

pp. 24-34

Author(s):

S. A. G AL-S amarrae ◽

F. J. K. AL- Mishhadani

Keyword(s):

Laser Radiation ◽

Respiratory Rate ◽

Wave Length ◽

In Vivo Study ◽

Attenuated Vaccine ◽

Neon Laser ◽

Helium Neon Laser ◽

Visible Laser ◽

Helium Neon

Attenuated 3rd stage larvae of Dictyocaulus filaria, by continuos emission of visible Helium- Neon laser of 1mW and a wave length of 632.8 nm for 2.5,5,10 and 15 minutes, were dosed twice orally to four groups of five kids each. The first dose contained 1000 larvae and after five weeks a second dose of 2000 larvae was given . A 5 th group of five kids was left as control. Results showed that attenuation at 2.5 min. exposure was insufficient as indicated by the increase in respiratory rate, eosinophilia and shading of larvae in the feaces. The results indicated that attenuation of Dictyocaulus filaria larvae at (5, 10 , and 15) min. exposure to laser radiation were efficient and safe to be used as attenuated vaccine .

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Adverse Health Effects of Exposure to Visible Laser Radiation in the General Population: A Review

ЗДОРОВЬЕ НАСЕЛЕНИЯ И СРЕДА ОБИТАНИЯ - ЗНиСО / PUBLIC HEALTH AND LIFE ENVIRONMENT ◽

10.35627/2219-5238/2021-29-9-44-49 ◽

2021 ◽

pp. 44-49

Author(s):

MD Petrova ◽

NYu Mal’kova

Keyword(s):

Laser Radiation ◽

General Population ◽

Health Effects ◽

Morphological Changes ◽

Public Awareness ◽

Adverse Health Effects ◽

Adverse Health ◽

Russian Science Citation Index ◽

Wide Range ◽

Visible Laser

Introduction: With the spread of laser technologies in various spheres of human activity, the number of exposures to laser radiation of a wide range of users unfamiliar with specifics of its health effects, including those in everyday life, has increased, thus resulting in an increased number of traumas in the general population in recent years. Objectives: To search for data on the biological mechanisms of action of visible laser radiation in Russian and foreign scientific literature and to analyze adverse health effects of this exposure encountered in domestic and international practice. Methods: We searched for Russian and foreign full-text open access literary sources in Russian Science Citation Index (RSCI) and PubMed databases of biomedical publications for 1969–2019 and selected the most appropriate ones for review. Results: Both Russian and foreign researchers note that human exposure to laser radiation induces specific and non-specific responses at all tissue levels of organization. The extent and nature of developing morphological changes depend on the radiation wavelength, exposure time, power, energy and its density per unit of the irradiated surface. Conclusions: Our findings suggest that portable laser pointers and powerful laser projectors may cause retinal damage, traumatic macular holes and, in some cases, loss of vision. Despite frequently registered good visual recovery, general availability of commercial laser devices poses potential danger, especially for minors, and substantiates the need to raise public awareness of laser safety.

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