Ruby Laser Research Articles

Laser treatment of congenital melanocytic nevi: a review of the literature.

Congenital melanocytic nevi (CMN) are nevi that are present from birth and occur in approximately 1% of newborns. CMN may be cosmetically disfiguring and are at risk for malignant transformation. For these two reasons, CMN are frequently treated. A variety of treatment modalities have been utilized with variable efficacy, including excision, dermabrasion, curettage, chemical peels, radiation therapy, cryotherapy, electrosurgery, and lasers. The current treatment of choice for CMN is surgical excision. However, some CMN occur in cosmetically sensitive areas, where a surgical scar is less acceptable, or in inoperable locations. For these reasons, there has been increasing interest in the potential for laser treatment of CMN. The lasers that have been studied to date for the treatment of CMN include pigment-specific lasers, including ruby (694nm), alexandrite (755nm), and Nd:yttrium aluminum garnet (YAG) (1064nm), as well as ablative laser treatment with CO2 laser (10,600nm) and Er:YAG (2940nm). To date, ruby lasers have been studied most extensively in the treatment of CMN. Ruby laser has been shown to improve the cosmetic appearance of some CMN and may be cautiously considered for lesions located in cosmetically sensitive areas that are less amenable to surgical excision. For very large CMN, ruby laser has been tried as an alternative to extensive surgical and grafting procedures. Dual treatment with Q-switched ruby laser and normal mode ruby laser may provide the best outcomes; however, multiple treatment sessions should be anticipated. The practicality and expense of multiple treatments should be discussed with the patient prior to initiating treatment. Importantly, because of the persistence of dermal nevus cells, lifelong follow-up is required for all laser-treated CMN, even those with excellent cosmetic effect.

Laser Scanning Vibrometry and Holographic Interferometry Applied to Vibration Study

The applications of high performance materials in the aerospace and in the automotive technology in the next years need to develop new vibration study, nondestructive testing, predictive maintenance and industrial control methods.The Laser Scanning Vibrometry and Holographic Interferometry methods of vibration study and nondestructive testing by modal analysis are described. The Laser Scanning Vibrometer PSV 400 is made by Polytec GmbH and the PSV software reconstructs the 3D model of the measured micro-deformation of the object. The holographic laser system HLS-3 from Lumonics Inc. has 100 MW ruby laser peak power and 30 ns pulse width.Using mechanical excitation to induce a measurable vibration, the Laser Scanning Vibrometry and Holographic Interferometry modal analysis measurements show up the vibrational signatures and the damaged areas of the objects made by high performance materials - polymers, composites.

Frozen ZnS Aqueous Suspension Nonlinear Optical Properties

The study of nonlinear effects, caused by nanosecond laser pulses’ impact on the frozen ZnS nanoparticles’ suspension, is presented. Laser pulses excite strong nanoparticles’ coherent vibrations in the near-terahertz range which lead to different nonlinear effects: X-ray emission, stimulated low-frequency Raman scattering, and luminescence. X-ray emission was observed as bright spots on the special X-ray film. This provides evidence that an X-ray propagates with narrow beams. Stimulated low-frequency Raman scattering is a result of light scattering by acoustic vibrations of nanoparticles. Its frequency shift corresponds to the nanoparticles’ eigenvibration frequencies and depends on the sample material and particle’s dimension. It was measured with the help of a Fabri-Perot interferometer in the range of dispersion $$16.67\,\hbox {cm}^{-1}$$ . For ZnS, the first Stokes component frequency shift is equal to 465 GHz. Under excitation by 20 ns ruby laser pulses, the luminescence of the frozen ZnS nanoparticles’ suspension was observed in two bands located at 480 nm and 510 nm. Its duration was more than 3 s.

Formation of highly toxic hydrogen cyanide upon ruby laser irradiation of the tattoo pigment phthalocyanine blue.

Since laser treatment of tattoos is the favored method for the removing of no longer wanted permanent skin paintings, analytical, biokinetics and toxicological data on the fragmentation pattern of commonly used pigments are urgently required for health safety reasons. Applying dynamic headspace—gas chromatography with mass spectrometric detection (DHS—GC/MS) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC—ToF-MS), we identified 1,2-benzene dicarbonitrile, benzonitrile, benzene, and the poisonous gas hydrogen cyanide (HCN) as main fragmentation products emerging dose-dependently upon ruby laser irradiation of the popular blue pigment copper phthalocyanine in suspension. Skin cell viability was found to be significantly compromised at cyanide levels of ≥1 mM liberated during ruby laser irradiation of >1.5 mg/ml phthalocyanine blue. Further, for the first time we introduce pyrolysis-GC/MS as method suitable to simulate pigment fragmentation that may occur spontaneously or during laser removal of organic pigments in the living skin of tattooed people. According to the literature such regular tattoos hold up to 9 mg pigment/cm2 skin.

다중 공진형 컨버터를 이용한 이중 캐비티 구조의 4Hz 의료용 루비레이저 시스템 개발

Various laser systems have been widely used in almost all industrial technologies because they have high energy density, directivity and coherence. Recently the clinical application is becoming wider in medical parts such as incurable disease, diagnosis and so on. Generally, ruby laser beam has the greatest efficacy for removing tattoos, freckle and other skin problem. But current medical ruby laser system has the maximum repetition rate of 2Hz and optical output beam energy of 1J. Many medical doctors really want to have a high repetition ruby laser system because that can reduce the operation time.BR We investigated a new ruby laser system with high repetition rate of 4Hz using double cavities. Furthermore, we develop a new power supply system adopting zero voltage switching(ZVS) to minimize switching loss by LLC resonant converter designed as 2kW class.

Synchrotron Radiation in France: The Early Years

At the beginning of the 1960s, outside the U.S., very few electron synchrotrons existed and synchrotron light studies were still in their infancy. At the Sorbonne in Paris, Yvette Cauchois, the Director of the Laboratoire de Chimie Physique, a well-known scientist specializing in the low X-ray energy range, had contacts with U.S. pioneers in synchrotron light studies such as L.G. Parrat and D.H. Tomboulian. She evaluated the potential of this new radiation source able to produce the photon energy range bridging UV and X-ray, a range at this time difficult to produce in the laboratory by windowless X-ray tubes or hot plasmas in vacuum with electric discharge and then using early pulsed ruby lasers.

Synergy Effect of Combination of Fractional CO2 and Fractional Q-switched Ruby Laser Treatment for Skin Rejuvenation

Synergy Effect of Combination of Fractional CO2 and Fractional Q-switched Ruby Laser Treatment for Skin Rejuvenation

Charles Hard Townes

Charles Hard Townes

Pulsed modification of germanium films on silicon, sapphire, and quartz substrates: Structure and optical properties

The structural and optical properties of thin Ge films deposited onto semiconducting and insulat� ing substrates and modified by pulsed laser radiation are studied. The films are deposited by the sputtering of a Ge target with a lowenergy Xe + ion beam. Crystallization of the films is conducted by their exposure to nanosecond ruby laser radiation pulses (λ = 0.694 μm) with the energy density W = 0.2-1.4 J cm -2 . During pulsed laser treatment, the irradiated area is probed with quasicw (quasicontinuouswave) laser radiation (λ = 0.532 and 1.064 μm), with the reflectance recorded R(t). Experimental data on the lifetime of the Ge melt are compared with the results of calculation, and good agreement between them is demonstrated. Through the use of a number of techniques, the dependences of the composition of the films, their crystal structure, the level of strains, and the reflectance and transmittance on the conditions of deposition and annealing are established.

Comparison of the Q-switched Nd:YAG and ruby laser in treating semipermanent makeup

Comparison of the Q-switched Nd:YAG and ruby laser in treating semipermanent makeup

Townes' contribution to nonlinear optics

In honour of the Fiftieth Anniversary of the Nobel Prize in Physics, this talk introduced the contributions of Nicholas Basov and Alexei Prokhorov, who shared the prize with Charles Townes. The talk then detailed the quantum electronics research of Townes, particularly at MIT, which was related to nonlinear optics. The years from 1961 to 1968 were particularly exciting, as the ruby laser enabled a wide variety of new physics to be discovered and explored.

Optical diagnostics of the laser-induced phase transformations in thin germanium films on silicon, sapphire, and fused silica

The in-situ procedure is used to study the modification of thin (200–600 nm) germanium films induced by nanosecond pulses of a ruby laser. The films are produced using the ion-beam or magnetron sputtering on single-crystalline silicon (Si), sapphire (Al2O3), and fused silica (α-SiO2) substrates. The results on the dynamics of the laser-induced processes are obtained using the optical probing of the irradiated region at wavelengths of λ = 0.53 and 1.06 μm. The results of probing make it possible to determine the threshold laser energy densities that correspond to the Ge and Si melting and the generation of the Ge ablation plasma versus the amount of deposited Ge and thermophysical parameters of the substrate. The reflection oscillograms are used to obtain the dependences of the melt lifetime on the laser-pulse energy density.

On the formation of nanostructures on a CdTe surface, stimulated by surface acoustic waves under nanosecond laser irradiation

The formation of nanoscale structures in the unirradiated part of a p-CdTe crystal surface irradiated by a nanosecond ruby laser is revealed and investigated. It is shown that their formation is caused by the effect of the long-range action of a laser pulse with an intensity of I = 20 MW/cm2. Nanoscale-structure formation is explained by the influence of the pressure gradient of the surface acoustic wave, in particular, within the “vacancy-pump” mechanism on the surface.

Lowering of stimulated Raman scattering threshold as a result of light capture

Stimulated Raman Scattering in globular photonic crystals and globular photonic glasses at different diameters of globules (250 – 400 nm) with embedded molecular liquids is studied under excitation by nanosecond or picoseconds laser pulses. Substantial decrease of Stimulated Raman Scattering threshold was observed. Such phenomenon was explained as the result of laser radiation field increase in globular photonic structures due to photonic density of states enhancement near the edges of photonic stop bands of photonic crystals and due to Mie resonance or whispering gallery modes effect revealing in photonic glasses. Stimulated Raman Scattering threshold lowering as a result of light capture in globular photonic crystals and photonic glasses opens the way to new efficient laser sources created on the base of composite globular photonic structures. Experimental data on spectra of Stimulated Raman Scattering in light and heavy waters are presented. As sources of exciting light the powerful ultra short solid state laser pulses with 532.0 nm wavelength and giant pulses of Ruby laser (694.3 nm) have been used. Several Stokes and anti-Stokes satellites were observed. Libration modes have been excited and resulted in some additional Raman bands at low frequency region and also as combining tones.

Adult onset dyschomatosis universalis.

Dear Editor: Dyschromatosis universalis hereditaria (DUH) is a rare hereditary skin disorder that is characterized by a mixture of small and irregularly sized hyperpigmented and hypopigmented macules of a mottled or reticulated pattern. The usual onset age of DUH is 6 years1. The common pattern of inheritance is generally autosomal dominant; however, rarely, a few cases show a sporadic pattern. Some authors named this form as dyschromatosis universalis (DU) instead of DUH2. We report a case of DU in a 29-year-old female patient with no family history and a late onset of the disease. A 29-year-old Korean woman presented with asymptomatic multiple pinhead to rice sized mottled hypopigmented macules with diffuse hyperpigmented patches on the abdomen and left upper arm (Fig. 1A). The hyperpigmented lesions, which had been noted 1 year previously, started initially on the abdomen and gradually spread to the left upper arm. She has no history of systemic disease or any previous cutaneous disease. She also denied any family history of skin discoloration or similar skin lesions. Fig. 1 (A) Multiple pinhead to rice sized mottled hypopigmented macules with diffuse hyperpigmented patches. (B) A closer view. (C) A biopsy specimen taken from a hyperpigmented lesion on the abdomen showed increased abundant melanin pigments in the epidermis ... A biopsy specimen taken from the hyperpigmented lesion on the abdomen showed increased abundant melanin pigments in the epidermis, with normal number and distribution of melanocytes on hematoxylin-eosin, Fontana Masson, and MART-1 stainning (Fig. 1B). In contrast, the histopathologic finding of a hypopigmented macule suggested a reduced amount of melanin pigments in the lesion area (Fig. 1C). On the basis of these findings, the diagnosis was concluded to be DU. We recommended treatment with Q-switched Nd:YAG laser for the hyperpigmented lesions; however, she refused the therapy. She has been followed without any changes. Rycroft et al.3 reported a case with no family history, but was associated with short stature and high tone deafness. In addition, Shono amd Toda4 reported a case with no family history and associated with photosensitivity and a neurosensory hearing defect. Also, Kim et al.2 reported a case that occurred in the patient at age 20 years, with a sporadic pattern and with no comorbid conditions. Some authors suggest that DU is a more appropriate name for the sporadic cases rather than DUH2. DU should be differentiated from other conditions showing both hyperpigmentation and hypopigmentation, such as generalized Dowling-Degos disease, xeroderma pigmentosum, dyskeratosis congenita and chronic radiodermatitis. DU generally does not involve a family history and present only dyschromatosis without systemic disorder. Various therapeutic trials, such as psoralen and ultraviolet A irradiation, thin split-thickness skin autograft, and Q-switched ruby laser have been tried to treat these lesions; however, there is no definitely effective treatment for both hyperpigmented and hypopigmented lesions. Recently, Kim et al.5 reported that they successfully treated the hyperpigmented lesions of DUH with a Q-switched Nd:YAG laser. Only a few cases of DU have been reported worldwide, and we could find only three cases in the Korean literature (Table 1)2,3,4. Particularly, adult-onset DU like our case is very unusual. Thus, we here report a case of DU occurring in a 29-year-old female patient with no family history. Table 1 Reported cases of dyschromatosis universalis in global literatures (including Korea)

Characteristics of laser-induced shock wave injury to the inner ear of rats.

Recently, the number of blast injuries of the inner ear has increased in the general population. In blast-induced inner ear injury, a shock wave (SW) component in the blast wave is considered to play an important role in sensorineural hearing loss. However, the mechanisms by which an SW affects inner ear tissue remain largely unknown. We aimed to establish a new animal model for SW-induced inner ear injury by using laser-induced SWs (LISWs) on rats. The LISWs were generated by irradiating an elastic laser target with 694-nm nanosecond pulses of a ruby laser. After LISW application to the cochlea through bone conduction, auditory measurements revealed the presence of inner ear dysfunction, the extent of which depended on LISW overpressure. A significantly lower survival rate of hair cells and spiral ganglion neurons, as well as severe oxidative damage, were observed in the inner ear exposed to an LISW. Although considerable differences in the pressure characteristics exist between LISWs and SWs in real blast waves, the functional and morphological changes shown by the present LISW-based model were similar to those observed in real blast-induced injury. Thus, our animal model is expected to be useful for laboratory-based research of blast-induced inner ear injury.

The structure and photoconductivity of SiGe/Si epitaxial layers modified by single-pulse laser radiation

The effect of nanosecond pulses of ruby laser radiation on the structural state and morphology of the epitaxial layers of a SiO0.5Ge0.5 solid solution on silicon with the initiation of a crystal-melt phase transition has been studied by electron microscopy. Data on the photoelectric parameters of the laser-modified layers having a cellular structure owing to the segregation of germanium during the solidification of the binary melt have been derived.

Lasers in dentistry - Thinking ahead…

Abstract Laser technology was introduced in the field of dentistry with a novel idea of overcoming few problems or drawbacks posed by the conventional methods. Theodore Maiman in 1960 introduced the first solid state ruby laser. Since then lasers have gained its popularity in different fields of dentistry. Laser in dentistry is now in vogue and now becoming a part of the dentist's armamentarium. This article gives an insight to the basics of laser physics, types of laser, mechanism of action, their interactions with biologic tissues and their advantage and disadvantage. How to cite this article Priya NK, Sowmya NK, Ashwini R, Madhushankari GS, Lasers in Dentistry - Thinking ahead… CODS J Dent 2014;6;102-107

Current Concepts in Aesthetic Laser Medicine: The 694-Nm Q-Switched Ruby-Laser

Quality-switched (q-switched) laser systems are the gold standard for the treatment of benign pigmented lesions and tattoo removal. A frequently used system is the q-switched ruby laser that emits monochromatic light at the wavelength of 694 nm. This system is used for the removal of age spots (senile lentigines), seborrhoeic keratosis, tattoos, and other dyschromatoses. The increasing need for the removal of, for example, age spots and unwanted tattoos, reflects both the wish of our ageing society to preserve a youthful appearance and the steadily growing prevalence of tattoos. This review highlights the potential, limitations, and novel treatment concepts of using q-switched ruby laser systems.

Fractional CO2 laser is as effective as Q-switched ruby laser for the initial treatment of a traumatic tattoo

Background and objective: Q-switched laser treatments are considered the standard method for removing both regular and traumatic tattoos. Recently, the removal of tattoo ink using ablative fractional lasers has been reported. Ablative fractional CO2 laser and q-switched ruby laser treatments were used in a split-face mode to compare the safety and efficacy of the two types of laser in removing a traumatic tattoo caused by the explosion of a firework. Study design/Patients and methods: A male patient suffering from a traumatic tattoo due to explosive deposits in his entire face was subjected to therapy. A series of eleven treatments were performed. The right side of the face was always treated using an ablative fractional CO2 laser, whereas the left side was treated only using a q-switched ruby laser. Results: After a series of eleven treatments, the patient demonstrated a significant lightening on both sides of his traumatic tattoo, with no clinical difference. After the first six treatments, the patient displayed greater lightening on the right side of his face, whereas after another five treatments, the left side of the patient's face appeared lighter. No side effects were reported. Conclusions: In the initial stage of removing the traumatic tattoo, the ablative fractional laser treatment appeared to be as effective as the standard ruby laser therapy. However, from the 6th treatment onward, the ruby laser therapy was more effective. Although ablative fractional CO2 lasers have the potential to remove traumatic tattoos, they remain a second-line treatment option.