Copper Vapor Laser Radiation Research Articles

Numerical Modeling of The Dysplastic Vessel Heating in PWS by Yellow 578 nm Copper Vapor Laser Radiation for Different Skin Phototypes.

Introduction: Many clinical studies and protocols have been written about laser treatment for fair skin phototypes. However, for dark-skinned phototypes, information is limited, and the risk of burns is higher, especially if the same settings are recommended for fair skin. Competitive epidermal melanin absorption decreases the light energy reaching dysplastic vessels in a port-wine stain (PWS), preventing the vessel from achieving the temperature of the desired clinical result. Therefore, the choice of safe laser settings for different skin phototypes can be realized using numerical modeling of PWS vessel heating. This study aimed to demonstrate the algorithm for choosing both effective and safe photodestruction of dilated dermal vessels in PWS with the copper vapor laser (CVL) at 578 nm for different skin phototypes. Methods: We used the multilayered skin model with different melanin content for detecting the safe laser parameters for PWS treatment. The calculation of the selective heating of the vascular component with CVL radiation at yellow 578-nm wavelengths for different skin phototypes was performed via Matlab mathematical programming system and its application Femlab for solving partial differential equations using the Finite element method. Results: We determined the location, depth, and size of blood vessels that could be selectively heated to coagulation temperature for different skin prototypes. CVL fluence values need to be reduced almost two times for skin phototype IV than for skin phototype II to provide safe CVL treatment. The maximum depth of the location of the vessels, which can be selectively heated to coagulation temperature, also decreased for dark skin phototypes. Histological and histochemical findings validated the results of our calculations. Conclusion: To our knowledge, the use of numerical simulation to optimize has not yet been considered. According to our calculations, CVL could selectively heat the dilated vessel, which occurred in purple and proliferative-type PWS for dark skin at the reduced fluence range and depth.

Treatment of Nevus Spilus with dual-wavelength copper vapor laser

Introduction. Speckled lentiginous nevus or Nevus Spilus (NS) is a congenital or acquired melanocytic nevus. NS appears as dark hyperpigmented macules or papules interspersed in the lentigo-like hyperpigmentation patch. Surgical methods for removing NS, primarily on the skin with a thin dermis, are associated with the risk of disruption of its structure or scarring. The use of single wavelength laser irradiation allowed achieving pronounced bleaching of the NS area with such side effects as scars, post-inflammatory hyperpigmentation, and relapses in some cases. Side effects could occur due to the lack of complete blood flow in the microvascular bed near the NS. The study aimed to evaluate the efficacy of NS treatment with a dual-wavelength copper vapor laser (CVL).
 Description of patients and the method of the treatment. Two fair-skinned adult female patients with NS, of medium size and different location, asked to restore the natural colour of the skin in order to get rid of cosmetic defects. NS treatment was carried out using CVL (Yakhroma-Med model, P.N.Lebedev Physical Institute of the Russian Academy of Sciences) during six procedures, an interval of 46weeks. For treatment, we used two-wavelength CVL radiation with average power in the range of 0.60.8W with a power ratio of 3:2 at wavelengths of 511 nm and 578 nm; exposure time: 0.20.3 s. The diameter of the light spot on the skin accounted for 1 mm. Both patients were satisfied with the result of the treatment due to the noticeable blanching of the pigmented skin area after the NS removal. During the following two years, no dark spots or scarring was observed at the NS removal site.
 Conclusion. Treatment of medium-sized NS using two-wavelength CVL radiation made it possible toeliminate the cosmetic defect without side effects.

Treatment of medium-sized facial nevus spilus with a dual-wavelength copper vapor laser

Nevus spilus (NS; synonym: speckled lentiginous nevus) − benign congenital or, more often, acquired melanocytic nevus − is characterized by numerous foci of hyperpigmentation located on a light brown background with possible transformation into malignant tumors. Its prevalence is ∼2% among the general population. NS sizes vary from 2 to 10 cm in diameter, but more extensive lesions have been described. Patients turn to a dermatologist when NS is located in aesthetically significant areas owing to cosmetic problems. Surgical methods for removing NS are associated with a risk of scarring. The use of various types of lasers for the treatment of NS has allowed successful results. However, it is accompanied by adverse effects such as scars, postinflammatory hyperpigmentation, and relapses. Our experience in treating benign melanocytic skin lesions using copper vapor laser (CVL) radiation, which allows selective heating of the pigment and blood vessels, gives us grounds for using CVL to treat NS. For the first time, we describe an innovative method of treating NS with dual-wavelength CVL radiation. A case of NS (medium size 50×40 mm) located in the cheek area was treated in a 39-year-old fair-skinned patient with type II skin, according to Fitzpatrick. NS treatment was carried out with the following parameters of the CVL (Yakhroma-Med model, P.N. Lebedev Physical Institute of the Russian Academy of Sciences): average power 0.6–0.8 W, with a power ratio of 3:2, at wavelengths of 511 and 578 nm. The pulse duration is 20 ns, the repetition rate is 16.6 kHz, the exposure time is 0.2–0.3 s, and the diameter of the light spot on the skin is 1 mm. After six treatments, the color of the hyperpigmented area, dark macules, and papules were eliminated. The follow-up period was 24 months. Medium-sized NS treatment with CVL provided complete elimination of the pathological focus and provided excellent cosmetic results. No relapse was observed within 24 months after treatment.

Treatment of pyogenic granuloma with copper vapor laser radiation

Background. Pyogenic granuloma (PG) or lobular capillary hemangioma, ICD10 code: L98.0. appears as a single bright red or violet papule up to 20 mm in size, on the face, fingers, skull surface, arms, and intergluteal fold, as well as on the oral mucous membranes. Surgical removal of facial PG is not always possible due to insufficient thickness of the dermis. Treatment of PG with a pulsed dye laser (PDL) or neodymium laser (Nd:YAG) can achieve a noticeable elimination of the lesion but is reported to be accompanied by such side effects as purpura or scarring. It determines the feasibility of introducing into clinical practice the methods of laser treatment of PG using the radiation of a copper vapor laser (CVL) with a wavelength of 578 nm, which effectively absorbed by the blood.
 Aim. The assessment of the clinical efficacy and safety of the CVL treating PG.
 Methods. 26 adult patients with PG in various parts of the face, including the lips, limbs, and trunk, were included in this study. PG treatment was carried out in one session with CVL (Yakhroma-Med, FIAN) at an average power of 0.71.0 W, at a wavelength of 578 nm, exposure time 0.20.3 s. The diameter of the light spot is 1 mm.
 Results. Immediately after the single laser treatment, the PG involved area became grey. In 710 days, the irradiated area was utterly similar to the adjacent intact skin. No postoperative bleeding or infection was noted. Side effects included mild skin atrophy. During the follow-up observation for five years, no side effects were found.
 Conclusion. The high efficiency of PG elimination using CVL in the absence of pronounced side effects allows suggesting this method for introducing into dermatologists and cosmetologists' clinical practice as a highly effective and inexpensive method of treatment.

Copper vapor laser treatment of granuloma of the vermilion border of the lips arising as a complication after permanent make-up

Background. Granulomas of the vermilion border of the lips (GVBL); as a complication of lip tattooing; inevitably poses cosmetic problems. Surgical excision and cryodestruction are associated with an increased risk of scarring and recurrence of GVBL. Laser therapy can selectively destroy a pigment and achieve the desired cosmetic result with minimal risk of side effects. So laser treatment was reported to be a more relevant method of treatment of GVBL.
 Aim. To evaluate the effectiveness of treatment of GVBL with copper vapor laser (CVL) radiation.
 Case report. 39-year-old female patient; without manifestations of systemic sarcoidosis; reported a 2-year history of granulomas of the lips vermilion border. She had a permanent makeup cosmetic tattoo before the onset of granulomas after lip tattooing. Histopathological examination revealed the presence of pigment in the upper and middle layers of the dermis. GVBL treatment was performed using a CVL during a single procedure; with an average CVL power of 0.60.8 W; with a ratio of 3:2 at wavelengths of 511 nm and 578 nm; exposure time 0.3 s. Light spot diameter 1 mm. CVL treatment led to a pronounced elimination of all GVBL without side effects within five years.
 Discussion. CVL allows a combined mode of exposure; consisting of grinding large granules of pigment to sizes that can be absorbed by the lymphatic system and suppressing VEGF expression using radiation with a wavelength of 578 nm.
 Conclusions. The CVL treatment provided an excellent cosmetic result due to selective photodestruction of the pigment and complete remodeling of the vascular bed associated with GVBL. The high clinical efficiency of eliminating post-tattooing foci of GVBL using CVL without side effects allows us to suggest this method for dermatologists and cosmetologists as a highly effective and inexpensive way to eliminate complications of permanent makeup.

Treatment of palpebral melanocytic nevi with a dual-wavelengths copper vapor laser

Acquired melanocytic nevi in aesthetically significant areas, especially palpebral nevi (PN), are becoming a frequent reason for patients to seek dermatologists. Surgical methods for removal of PN are reported to be associated with the risk of such side effects as scars and loss of eyelashes.
 Aim of the study. To evaluate the efficacy of the removal of PN on the eyelid area with dual-wavelength radiation of a copper vapor laser (CVL).
 Patients and methods. Laser removal of medium and large-sized PN (up to 10 mm) was performed in three fair-skin female patients. The procedures were carried out at an average CVL radiation power of 0.60.8 W, at a 3:2 ratio of radiation powers at wavelengths of 511 nm and 578 nm, exposure duration 0.3 s, light spot diameter 1 mm. The treatment was carried out during one session.
 Results. Removal of PN with dual-wavelength CVL radiation allowed achieving a significant lightening and reduction of the involved area, without scars. The skin healing after the procedure lasted 2 weeks.
 Conclusion. The high efficacy of the PN removing in the eyelid area using the dual-wavelength CVL radiation allows the introduction of this approach into dermatologists and cosmetologists clinical practice.

Treatment of palpebral melanocytic nevi with a dual-wavelengths copper vapor laser

Acquired melanocytic nevi in aesthetically significant areas, especially palpebral nevi (PN), are becoming a frequent reason for patients to seek dermatologists. Surgical methods for removal of PN are reported to be associated with the risk of such side effects as scars and loss of eyelashes.
 Aim of the study. To evaluate the efficacy of the removal of PN on the eyelid area with dual-wavelength radiation of a copper vapor laser (CVL).
 Patients and methods. Laser removal of medium and large-sized PN (up to 10 mm) was performed in three fair-skin female patients. The procedures were carried out at an average CVL radiation power of 0.60.8 W, at a 3:2 ratio of radiation powers at wavelengths of 511 nm and 578 nm, exposure duration 0.3 s, light spot diameter 1 mm. The treatment was carried out during one session.
 Results. Removal of PN with dual-wavelength CVL radiation allowed achieving a significant lightening and reduction of the involved area, without scars. The skin healing after the procedure lasted 2 weeks.
 Conclusion. The high efficacy of the PN removing in the eyelid area using the dual-wavelength CVL radiation allows the introduction of this approach into dermatologists and cosmetologists clinical practice.

Treatment of сongenital melanocytic nevus in infants and children by a dual-wavelengths copper vapor laser

Introduction.Congenital melanocytic nevus (CMN) is detected at birth or shortly after birth in 1% of infants. The localization of CMN in aesthetically significant areas causes a decline in child self-esteem and causes concern for his parents. Surgical excision of skin areas with CMN is associated with an increased risk of cosmetic side effects and is often followed by long-term stress conditions after the invasive intervention.
 Aim of the study.To evaluate the efficacy of the CMN removal in infants, children and adolescents with the dual-wavelengths copper vapor laser (CVL) radiation.
 Patients and Methods.Medium-sized (up to 9 cm) single CMN was treated in nine fair-skinned patients: seven girls and two boys, aged from 2 months to 16 years. The procedures were carried out at an average CVL power of 0.61.0 W, with a power ratio of 3:2 at 511 nm and 578 nm wavelengths, and an exposure time of 0.20.3 s. Light spot diameter 1 mm. The treatment was carried out during 210 sessions with an interval of 12 months between sessions.
 Results.In children and adolescents, the treatment of CMN with CVL dual-wavelengths radiation made it possible to achieve significant clarification of the involved area without hypertrophic scars. The duration of the healing of the irradiated area lasted 23 weeks. Side effects were manifested with subtle skin atrophy.
 Conclusion.The high efficacy of CVL removal of medium-sized CMN in infants and children using the dual-wavelengths CVL radiation without pronounced side effects allows introducing such an approach in the clinical practice of pediatric dermatologists and cosmetologists.

Treatment of rhinophyma using a copper vapor laser

Background. Rhinophyma is considered to be the most severe stage of rosacea, associated with the proliferation of the nose skin epithelium, hyperproduction of the sebaceous glands and telangiectasia.The treatment of rhinophyma remains a difficult task. One of the problems associated with rhinophyma is thickened and lumpy skin, penetrated with telangiectasias. The use of laser radiation in the treatment of rhinophyma seems to be promising, since this method allows blood vessels to be selectively heated.For the first time, we describe the treatment of rhinophyma using a copper vapour laser (CVL) equipped with a computerized scanner.Patient description. A 63-year-old male with Fitzpatrick skin type II was treated using an CVL (‘Yakhroma-med' model, RaS P. N. Lebedev Physical Institute). The clinical manifestations of the disease were typical of the phymatous or hypertrophic rhinophyma type, including significant thickening of the tissues and an uneven roughness of the skin surface. The treatment was carried out using a radiation wavelength of 578 nm, exposure duration of 0.2 s and energy exposure (fluence) of 15-30 J/cm2. Operational parameters used for the CVL in the scanner mode were the average power of 0.6-1.2 W and the focusing size of the light spot on the skin of 0.6 mm. The hexagonal mode of the scanning head was used with a maximum size of 12 mm and 1 mm distance between the centres of the laser spots. The treatment resulted in the restoration of the natural nose shape without redness. No side effects were noted.Conclusion: CVL radiation provided a selective photodisruption of the vessels with increased diameter.Due to the remodelling of the vasculature, the described method showed excellent results in the treatment of rhinophyma without side effects.

Comparative numerical analysis and optimization of blood vessels heated using various lasers

Numerical simulation was introduced to study selective vessel heating using diode laser, Nd:YAG laser, copper vapor laser and pulsed dye laser radiation. The vessels’ location depth and size were determined, which could ensure selective heating of the vessels to the coagulation temperature. These results are in good agreement with clinical findings, and the validity of our model is confirmed.

Features of Copper Vapor Laser Emission Excited by Pulse-Periodic HF Discharge

The results of numerical studies of pulsed radiation of the induction copper vapor laser are presented. The laser is excited by trains of high-frequency (10–70 MHz) electric current oscillations. Trains follow one after another with a frequency in 2–17 kHz. The features and variety of obtained laser radiation pulse shapes and their applicability to diagnostic purposes and other practical problems are discussed.

THERAPY OF SKIN VASCULAR MALFORMATIONS USING COPPER VAPOR LASER AND PULSED DYE LASER

Aim. Comparison of effectiveness of the application of copper vapor laser (CVL) and pulsed dye laser (PDL) in clinical practice. Development of choice criteria of the more effective method of treatment.Materials and methods. The clinical data using CVL and PDL in the treatment of skin vascular malformations are presented. The treatment gave good results in removing of dysplastic skin vessels in 2 and 6 months. The treatment was not painful, and patients did not need general and local anesthesia. The results were presented concerning computer modeling of selective heating of vessels in tissue with CVL and PDL radiation. These results allowed to determine the depth of location and dimensions of vessels for selective and secure removing and the safe dosage ranges were found.Results. On the base of the calculated data, one could conclude that the mode of heating of dysplastic vessels with micropulse series of CVL is more safe and effective than the mode of powerful short pulses in the case of PDL.

Laser-induced fluorescence method of molecular iodine detection in the atmosphere in real time using copper-vapor laser at the wavelength of 510.6 nm

The method of simultaneously detecting 127I2 and 127I129I in the atmospheric air is proposed. The method is based on exciting fluorescence of the molecules in question by copper-vapor laser radiation at the wavelength of 510.6 nm and registering intensities of their individual fluorescence spectral lines. The values of minimal real-time measured relative concentrations of 127I129I being mixed with 127I2 are approximately 10−6. This method can be used for the ecological monitoring of iodine-129 in the atmosphere.

Copper-Vapor Laser Induced Local Crystallization of Glasses in the System Li2O–B2O3–GeO2

Experiments on local modification of lithium-borogermanate (LBG) glass with the composition (molar fraction, %) 25Li2 O ∙ 25B2O3 ∙ 50GeO by copper-vapor laser radiation on the main lasing lines (510.6 and 578.2 nm) in the visible range and on the sum frequency in the UV range (271 nm) are described. Local surface crystallization of LBG glass by a laser beam with 2 – 15 μm crystals precipitated by means of laser heating of the sample at temperature somewhat below t g is demonstrated for the first time. X-ray phase analysis and confocal RS spectroscopy show that the polar phase LiBGeO4 is the only phase formed as a result of crystallization. Crystallization obtains with UV- and visible-range radiation.

Using a copper-vapor laser (578.2 nm) in a new method of laser fluorescence for molecular iodine isotopes to detect gases in real time

This letter deals with the development of a new laser method for simultaneously detecting 127I2, 127I129I and 129I2 in gaseous media, which, in contrast with existing methods, does not require tuning of the laser wavelength. The method is based on exciting fluorescence in iodine isotopologues using copper-vapor laser radiation (578.2 nm) and registering the separate spectral fluorescence line intensities. This method allows high-sensitivity real-time monitoring of isotopologues of molecular iodine-129 and iodine-127 in technological media generated during the reprocessing of spent nuclear fuel, in gaseous emissions from the purification systems of radiochemical plants and in the natural atmosphere.

Fluorescence of iodine-127 and iodine-129 isotopes excited by radiation of copper vapor laser (510.6 nm)

The paper deals with the study of 127I2, 127I129I and 129I2 fluorescence excited by radiation of a copper vapor laser at 510.6 nm. Iodine molecule absorption lines, resonant at the wavelength of laser radiation, were identified. The obtained results were compared to those obtained while exciting fluorescence with lasers radiating at wavelengths 578.2 and 532 nm. It was shown that copper vapor lasers with a wavelength of 510.6 are promising for performing high-sensitive real-time detection of molecular iodine-129 in gaseous media. The obtained results may be used for developing totally new cost-effective and environmentally friendly technologies of electricity generation, based on fast reactors, which is extremely important for providing humanity with environmentally friendly generated electric energy.

Atmospheric bistatic communication channels with scattering. Part 1. Methods of study

The paper considers the methods for theoretical and experimental study of bistatic optical communication schemes. A laboratory model of an optoelectronic communication system has been developed for experimental studies. Copper-vapor laser radiation at a wavelength of 510 nm was used as a source of signals. Test demonstration experiments were performed in the real atmosphere through atmospheric channels with a reflecting surface and a dense nonstationary aerosol-molecular structure. For theoretical studies, software means were developed for numerical statistical estimation of the energy and transfer characteristics of the bistatic atmospheric communication channels by the Monte Carlo method.

Fluorescence of iodine-127 and iodine-129 isotopes excited by radiation of copper vapor lasers (578.2 nm): I. Fluorescence of 127I2

This two-part paper reports the results of the first theoretical and experimental studies of the fluorescence of molecular iodine-127 and iodine-129 isotopes excited by copper vapor laser radiation (578.2 nm). This first part deals with the study of iodine-127 fluorescence. Excited transitions were identified, and obtained fluorescence spectra were investigated in detail.

Effect of pulse to pulse variation of divergence, pointing and amplitude of copper vapor laser radiations on their second harmonic and sum frequency conversion

This paper presents the effect of single pulse stability of divergence angle, beam pointing angle and amplitude of green and yellow radiation pulses of an unstable resonator copper vapor laser (CVL) oscillator in the sum frequency (SF) mixing and second harmonic (SH). The conversion efficiency of sum frequency generation was lower compared to second harmonic processes despite larger fundamental power being used in sum frequency experiments. However the net UV power obtained at the sum frequency was higher than both of the second harmonic UV frequencies. Lower sum frequency generation (SFG) conversion efficiency compared to second harmonic generation (SHG) of individual CVL radiation is attributed to difference in single pulse stability of beam pointing, divergence and amplitude fluctuation of both CVL radiations in addition to commonly known fact of spatio-temporal mis-match. At the same fundamental input power, higher SH conversion efficiency of yellow compared to green is attributed to its better single pulse stability of beam pointing and divergence.

Effects of Copper Vapor Laser Radiation on the Root Canal Wall of Human Teeth: A Scanning Electron Microscope Study

The aim of this study is to analyze the effects of copper vapor laser radiation on the radicular wall of human teeth. Immediately after the crowns of 10 human uniradicular teeth were cut along the cement-enamel junction, a chemical-surgical preparation of the radicular canals was completed. Then the roots were longitudinally sectioned to allow for irradiation of the surfaces of the dentin walls of the root canals. The hemi-roots were separated into two groups: one (control) with five hemi-roots that were not irradiated, and another (experimental) with 15 hemi-roots divided into three subgroups that were submitted to the following exposure times: 0.02, 0.05, and 0.1 s. A opper vapor laser (510.6 nm) with a total average power of 6.5 W in green emission, frequency of 16.000 Hz, and pulse duration of 30 ns was used. The results obtained by scanning electron microscope analysis showed the appearance of a cavity in the region of laser beam impact, with melting, recrystallization, and cracking on the edges of the dentin of the cavity due to heat diffusion. We determined that the copper vapor laser produces significant morphologic changes in the radicular wall of human teeth when using the parameters in this study. However, further research should be done to establish parameters that are compatible with dental structure in order to eliminate thermal damages.