Showing papers on "Ruby laser published in 2022"

Comparative treatments of a green tattoo ink with Ruby, Nd:YAG nano- and picosecond lasers in normal and array mode

Abstract: The tattoos removal has become an issue upon spread of the tattooing practice worldwide and hindsight regrets. Lasers are typically used for the purpose, though some colours such as green are considered "recalcitrant" to the treatment. In the current investigation, we aim at determining the efficacy of removal of a green ink water dispersion, using 5 laser treatments: Nd:YAG nano- and picosecond lasers in normal and array mode and Ruby nanosecond laser, keeping the total irradiated energy constant. The UV-Vis spectroscopy of the treated samples indicate that Nd:YAG picosecond laser is most effective, and the Ruby nanosecond laser is the least efficient. Fragment compounds generated from the pigment and siloxanes are common to all treatments, whereas hydrocarbon emerge by a larger amount upon Nd:YAG nanosecond treatment. Fibres are formed upon picosecond treatments and when operating in array mode, and lamellae are achieved by Ruby nanosecond laser treatment. Residual particles suspensions are very heterogeneous upon nanosecond treatments.

Treatment of melasma using a combination of CO2 laser and Q-switched ruby laser

Abstract: Other SectionsAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONCONFLICT OF INTERESTAUTHOR CONTRIBUTIONSFUNDINGReferences

Treatment of linear and whorled nevoid hypermelanosis using QS 694-nm ruby laser

Abstract: ABSTRACT Laser is being widely used in treating pigmented lesions nowadays. Linear and whorled nevoid hypermelanosis (LWNH) is a rare pigmentary anomaly, and there are only a handful of cases of successful treatment, all with QS 532- and 755-nm laser. The objective of this study was to examine the clinical outcome of QS 694-nm ruby laser in the treatment of LWNH. We report on a 4-year-old boy presented with asymptomatic macular hyperpigmentation over the entire cheek who underwent 3 treatment sessions with QS 694-nm ruby laser. One month after the last treatment, the patient demonstrated significant improvement to the treatment area. Aside from post-procedural purpura lasting approximately 1 week, the patient experienced no serious adverse effects. No recurrence was observed during the 3-month follow-up. Given the excellent results seen in our patients, we recommended the use of QS 694-nm ruby laser as a safe and effective treatment in patients with LWNH.

On the invasiveness of the electro-optical research methods in strong inhomogeneous electric and light fields

Abstract: <p>In the manuscript, as a result of comparing experimental and calculated kerrograms, it is shown that during electro-optical measurements in nitrobenzene using the Kerr effect, a strong electric field and absorption of radiation from a probing laser affect the properties of the medium under study. An estimate of such influence on the value of the Kerr constant is made. It is found that in the tip-plane system when using a ruby laser, the Kerr constant near the tip changes. The established dependence of the Kerr constant on the distance to the tip made it possible to obtain a calculated kerrogram that coincides with the experimental one. Thus, it is shown that the measuring instruments can influence the results obtained, that is, under certain conditions, the electro-optical research method is invasive. This fact should be taken into account when processing experimental kerrograms.</p>

Q-Switched Ruby Laser, Absorption Coefficient, and Spot Size Effect

Abstract: Wavelength of Q-switched ruby ​​laser is 694 nm, which has the highest absorption coefficient for melanin compared to hemoglobin (Table 4.1). The pulse duration (PD) of the Q-switched ruby ​​laser is 40 ns and TRT of melanosome is 250–100 ns [1, 2], and because TRT > PD in selective photothermolysis, Q-switched ruby ​​laser is suitable for treating melanosomes. However, in Q-switched ruby ​​lasers, our actual target is not melanosomes, which are subcellular organelles, but rather cells such as keratinocytes or melanocytes that have melanosomes. Since TRT (15–30 μs [3]) of cells is too large compared to PD (<50 ns) of Q-switched laser, Q-switched laser cannot directly destroy the cells, but a photoacoustic effect (a type of photomechanical effect) that causes shock waves or cavitation can be used to blast melanosomes to damage the nucleus or cell membrane of cells, thereby indirectly destroying keratinocytes or melanocytes to cause necrosis (refer to Sect. 1.11 in Chap. 1 ).

On the invasiveness of the electro-optical research methods in strong inhomogeneous electric and light fields

Abstract: <p>In the manuscript, as a result of comparing experimental and calculated kerrograms, it is shown that during electro-optical measurements in nitrobenzene using the Kerr effect, a strong electric field and absorption of radiation from a probing laser affect the properties of the medium under study. An estimate of such influence on the value of the Kerr constant is made. It is found that in the tip-plane system when using a ruby laser, the Kerr constant near the tip changes. The established dependence of the Kerr constant on the distance to the tip made it possible to obtain a calculated kerrogram that coincides with the experimental one. Thus, it is shown that the measuring instruments can influence the results obtained, that is, under certain conditions, the electro-optical research method is invasive. This fact should be taken into account when processing experimental kerrograms.</p>