Continuous-wave diode laserthermokeratoplasty: First clinical experience in blind human eyes

The Nobel Prize in Physics 2018, “For groundbreaking inventions in the field of laser physics”, went to Arthur Ashkin and Gérard Mourou and Donna Strickland. Their inventions have revolutionized laser physics and greatly promoted the development of laser instruments, which have penetrated into many aspects of people’s daily lives. However, for the purpose of protecting human eyes or optical instruments from being damaged by both pulsed and continuous wave laser radiation, the research on laser protective materials is of particular significance. Due to the intriguing and outstanding physical, chemical, and structural properties, two-dimensional (2D) nanomaterials have been extensively studied as optical limiting (OL) materials owing to their broadband nonlinear optical (NLO) response and fast carrier relaxation dynamics that are important for reducing the laser intensity. This review systematically describes the OL mechanisms and the recent progress in 2D nanomaterials for laser protection.

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An In-Situ Study of Laser-Induced Plume Radiance and Thermal Effects of Laser Irradiated Polycarbonate and Poly(Methyl Methacrylate) Samples

MRS Proceedings ◽

10.1557/proc-201-483 ◽

1990 ◽

Vol 201 ◽

Author(s):

Pearl W. Yip

Keyword(s):

Methyl Methacrylate ◽

Thermal Effects ◽

Continuous Wave ◽

Test Results ◽

Poly Methyl Methacrylate ◽

In Situ Study ◽

Military Applications ◽

Recovery Times ◽

Human Eyes

AbstractThreats of lasers to human eyes and electro-optics on the modern battlefield has been significantly increased due to the rapid growth of laser technology in military applications. Currently polycarbonate (PC) and poly [methyl methacrylate] (PMMA) are being used as transparencies for aircraft and goggle materials for aircrews and combat soldiers [Ref 1,2]. A carefully monitored laser test was conducted on these two particular polymers using a medium-power, continuous-wave CO2 laser to determine the brightness of the laser-induced plume radiance and how much luminance was transmitted to the back of the sample. Plume luminance for photopic (daytime) and scotopic (nighttime) visual conditions, as well as the recovery times for human eyes exposed to these levels of luminance were calculated. Our test results demonstrated that the plume induced by the CW CO2 laser irradiation can be an ocular hazard to soldiers operating behind these conventional transparent materials.

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Two-Micron Continuous-Wave Laser-Assisted Neuroendoscopy: Clinical Experience of Two Institutions in 524 Procedures

World Neurosurgery ◽

10.1016/j.wneu.2018.09.064 ◽

2019 ◽

Vol 122 ◽

pp. e81-e88 ◽

Cited By ~ 1

Author(s):

Martin U. Schuhmann ◽

Cahit Kural ◽

Lisanne Lalla ◽

Florian H. Ebner ◽

Christoph Bock ◽

...

Keyword(s):

Clinical Experience ◽

Continuous Wave ◽

Continuous Wave Laser ◽

Wave Laser

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Microstructures of Laser Processed Fe-Cr Surface Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098150 ◽

1981 ◽

Vol 39 ◽

pp. 328-329

Author(s):

P. A. Molian ◽

K. H. Khan ◽

W. E. Wood

Keyword(s):

Cooling Rate ◽

Pure Iron ◽

Continuous Wave ◽

Laser Surface ◽

Material Surface ◽

Constitution Diagram ◽

Incident Power ◽

Surface Alloying ◽

Laser Surface Alloying ◽

Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

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