308-nm Excimer Laser Research Articles

Effectiveness of 308-nm Excimer Laser Therapy in Treating Alopecia Areata, Determined by Examining the Treated Sides of Selected Alopecic Patches

Background: Some studies have reported the use of 308-nm excimer laser therapy for treating alopecia areata (AA); however, the effectiveness of this therapy on a theoretical basis has not yet been comparatively analyzed. Objectives: To determine the therapeutic effect of excimer laser therapy on AA. Methods: One alopecic patch was divided into control and treated sides in 10 patients with AA. Then, 308-nm excimer laser therapy was administered twice a week for 12 weeks. Photograph and phototrichogram analyses were performed. Results: Photographic assessments by both dermatologists and individuals of the general population showed objective improvements after excimer laser therapy. On the treated side, the hair count and hair diameter had statistically increased after treatment. However, only the hair diameter was found to be significantly high in the treated half when it was compared with the control side. Conclusion: The 308-nm excimer laser has a therapeutic effect on AA, which is proven by photograph and phototrichogram analysis by a side-by-side comparison.

Combination therapy with 308-nm excimer laser, topical tacrolimus, and short-term systemic corticosteroids for segmental vitiligo: A retrospective study of 159 patients

Segmental vitiligo (SV) is characterized by a unilateral and localized distribution, early onset, and stable disease after rapid progression. And SV is often associated with poor response to various treatment modalities. We sought to evaluate the effectiveness of combination therapy with 308-nm excimer laser, topical tacrolimus, and short-term systemic corticosteroids for SV, and to search for factors associated with the treatment response. A retrospective interventional case-series study was performed on 159 patients with SV who were treated with the combination therapy for more than 3 months. The rate of 75% or more repigmentation was 50.3% after a median treatment duration of 12.1 months; 36.5% and 13.8% of the patients showed nearly complete (75%-99%) and complete (100%) repigmentation, respectively. Multivariable analysis showed the following to be independent factors withpoor response: disease duration longer than 12 months (odds ratio 0.372, 95% confidence interval 0.157-0.882, P= .025), poliosis (odds ratio 0.494, 95% confidence interval 0.247-0.988, P= .046), and plurisegmental subtype (odds ratio 0.175, 95% confidence interval 0.065-0.474, P= .001). This was a retrospective study. The combination therapy is effective for SV. Prolonged disease duration, poliosis, and plurisegmental subtype were shown to be independent prognostic factors of poor response in patients with SV.

UV-induced red fluorescence on facial part of patients with acne vulgaris and seborrheic dermatitis: a fluorescence spectrum study

Objective To measure the fluorescence spectral information of UVRF in the facial skin of patients with acne vulgaris and seborrheic dermatitis and to comprehend the optical properties of UVRF. Methods The lesions were squeezed to extract the sebaceous secretions containing UVRF in the facial skin. Ocean Optics USB2000+ F02243 Spectrometer and the 308nm excimer laser were used as an excitation light source to measure the signal of the LIF spectrum of UVRF in 6 acne vulgaris and 4 seborrheic dermatitis patients' facial part, compared with protoporphyrin Ⅸ. Results 1-4 peaks were detected in 10 patients' UVRF specimen respectively. The fluorescence spectra's characteristic peak of UVRF in 10 patients was at 680 nm. Protoporphyrin Ⅸ was at 688 nm and more gentle and generous than UVRF's characteristic peak. Conclusions LIF system can be used to detect the fluorescence spectroscopy of UVRF. UVRF has similar spectral characteristics to protoporphyrin Ⅸ, but it is not the same species. Key words: Acne; Seborrheic dermatitis; Fluorescence spectrum; Red fluorescence; Laser induced fluorescence

Demonstration of 10-<inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m Microvias in Thin Dry-Film Polymer Dielectrics for High-Density Interposers

This paper describes the demonstration of 10-μm diameter interlayer vias with 3.5-μm wide re-distribution layer copper wiring in a unique dry-film polymer dielectric, ZEONIF ZS100 (ZS100), suitable for panel-based high-density organic and glass interposers. The uniqueness of polymer dielectric includes low dielectric constant, low dielectric loss, low moisture uptake, and low surface roughness. The dry-film polymer dielectric was laminated on thin and low coefficient of thermal expansion organic or glass cores using double-side vacuum lamination processes. The ultrasmall microvias were drilled with 248-nm KrF excimer laser. Metallization by electroless and electrolytic copper plating successfully achieved formation of fully filled vias and copper traces simultaneously without any chemical-mechanical polishing. The processes demonstrated in this paper enable interposers with much finer bump pitch than current organic package technology. In addition, the processes can be scaled to large panels leading to lower cost than the previous work in fine pitch Si interposers fabricated through back-endof-line wafer processes.

Fractionated CO2 laser combined with 308-nm excimer laser for the treatment of stable vitiligo: an observational clinical study

Objective To evaluate the efficacy and safety of fractionated CO2 laser combined with 308-nm excimer laser for the treatment of stable vitiligo.Methods Forty-nine patients with 109 lesions of stable vitiligo were enrolled in this clinical trial.Each of these lesions was equally divided into 2 parts along the longest diameter,which were then assigned into the treatment group and control group respectively.The treatment group were treated with fractionated CO2 laser radiation for 15-20 minutes once every two weeks combined with 308-nm excimer laser radiation twice weekly.The control group were only treated with 308-nm excimer laser radiation twice weekly.Efficacy was evaluated on day 3 after 12 consecutive weeks of treatment.Results After the treatment,the total response rate in the treatment group and control group was 92.7％ (101/109) and 77.1％ (84/109) respectively.The marked response rate in the treatment group and control group was 85.4％ (35/41) and 65.8％ (27/41) respectively for lesions on the face and neck (x2 =4.23,P ＜ 0.05),70.6％ (24/34) and 41.2％ (14/34) respectively for lesions on the trunk (x2 =7.27,P＜ 0.01),64.0％ (16/25) and 36.0％ (9/25) respectively for lesions on the extremities (x2 =3.92,P ＜ 0.05),5/9 and 1/9 respectively for lesions on the dorsal hands (X2 =4.00,P ＜ 0.05).The number of sessions of 308-nm excimer laser therapy required for the marked response of vitiligo in the treatment group and control group was 7.24 ± 1.23 and 10.81 ± 2.01 respectively for lesions on the face and neck (t =9.70,P ＜ 0.05),15.10 ± 2.47 and 18.95 ± 3.45 respectively for lesions on the trunk (t =5.29,P＜ 0.05),17.37 ± 3.84 and 21.06 ± 4.23 respectively for lesions on the extremities (t =3.23,P ＜ 0.05).No severe adverse reactions were observed in any of the patients during the treatment.Conclusion Fractionated CO2 laser combined with 308-nm excimer laser is effective and safe in treating stable vitiligo. Key words: Vitiligo; Fractional laser; Efficacy

Radiation-induced Alopecia Treated with Botulinum Toxin Type A Injection.

1 Moo Yeol Hyun, MD Beom Joon Kim, MD, PhD Department of Dermatology Chung-Ang University College of Medicine Seoul, Korea Changjin Lee, MD, PhD Jae Wook Kim, MD, PhD Hugel, Inc. Gangwon-do, Korea Sir: B toxin type A (BTXA) has been in use for more than 20 years in the treatment of various neurological conditions and aesthetic treatments.1,2 BTXA is also occasionally used to treat alopecia; however, the efficacy of BTXA in alopecia remains unclear. A 65-year-old woman presented with a history of diffuse hair loss in the frontoparietal scalp after carniosurgery and radiotherapy for a meningioma 1 year before her visit. Physical examination revealed diffuse hair loss and a linear depression on the frontoparietal scalp caused by surgery (Fig. 1). Because she refused our suggestion for biopsy to evaluate the degree of fibrosis, we diagnosed her condition as radiation-induced alopecia based on clinical evidences. We initially treated her with an intralesional injection of triamcinolone acetonide (5 mg/ml) monthly and with a 308-nm excimer laser (Xtrac laser, Photomedex, Montgomeryville, PA.) every other week for 1 year. However, the patient’s response to these treatments was limited. Thus, we decided to combine the above treatments with injection of BTXA (Botulax; Hugel Pharma, Seoul, Korea). To this end, we injected 150 U of Botulax (5 U per 0.1 ml saline) into the muscles surrounding the patient’s scalp, including the frontalis, temporalis, periauricular, and occipitalis muscles, in doses divided equally over 30 injection sites every 3 months for 12 months. After 3 months, sparse vellus hairs were observed, and after 12 months, hair density and thickness were improved, and she had some hair growth on the frontal scalp. The scalp was also slightly softer and more sanguine in appearance compared with the scalp before botulinum toxin injections were initiated (Fig. 2). In our case, BTXA induced idiopathic hair growth, although the mechanism by which this took place remains unclear. We speculated that BTXA injections facilitated tension relief of muscles surrounding the scalp and increasing perifollicular blood flow decreased by radiation damage.3 A pilot study by Freund and Schwartz4 reported treatment of male pattern baldness with botulinum toxin. They asserted that BTXA “loosens” the scalp, which in turn reduces pressure on the perforating vasculature to allow for increased blood flow and oxygen concentration. Likewise, in Cutrer and Pittelkow’s5 case

Photopatternable Laminate BCB Dielectric

Divinylsiloxane-bis-benzocyclobutene (DVS-bis-BCB, or BCB) is a well-known dielectric material that has been used in high volume manufacturing for many years (Dow's CYCLOTENE™ 3000/4000-series Advanced Electronic Resins). Typically, the application of these products has been by spincoating or spray coating of the dielectric material from a solvent-based formulation. However, for certain applications - for example, those involving large area, square substrates such as glass panels - it is desirable to be able to apply the BCB-based dielectric material using a dry film coating process, such as vacuum or hot roll lamination. In this paper, we describe the concept of creating a laminate film utilizing DVS-bis-BCB as the primary dielectric material component. In creating the laminate dielectric material, it is important to maintain the unique combination of thermal and electrical properties of DVS-bis-BCB, including high thermal stability, excellent copper barrier properties, low moisture uptake, low dielectric constant, and low dielectric loss. However, DVS-bis-BCB alone is too rigid to produce a high quality laminate film, therefore, it is necessary to modify the formulation to improve flexibility and lamination quality. As the flexibility of the film is increased, higher fracture toughness (K1C) and higher elongation values should result. Novel formulation adjustments to the base DVS-bis-BCB polymer system have resulted in an experimental laminate dielectric product that will be the focus of this discussion. Depending on the application, laminate films can vary in thickness from 2μm to 50μm or even thicker. A typical laminate film construct includes the BCB-based dielectric film with a base sheet of an optically-clear polyester (PET) film and a polyethylene (PE) cover sheet. The DVS-bis-BCB-based laminate can be tuned with appropriate additives to either pattern with UV exposure from a tool such as a Süss MicroTec Mask Aligner (50mJ/cm2 – 100mJ/cm2 exposure energy) or laser pattern with a tool such as a Süss MicroTec 248nm Excimer Laser. Aspect ratios of 1:1.5 have been achieved with a photopatternable DVS-bis-BCB film and aspect ratios of >1:1 are possible with a laser-patterned film. Beside the photopackage added to the film to enable UV patterning, toughening additives have also been incorporated to enhance the fracture toughness (K1C) and elongation properties. K1C for the laminate has been improved to 0.55Mpa·m1/2 vs. 0.35Mpa·m1/2 for DVS-bis-BCB. Elongation has been improved to 13% for the laminate vs. 8% for DVS-bis-BCB. Electrical properties are similar to DVS-bis-BCB. An additional attribute of the laminate dielectric is the ability to tent over and protect vias. Vias >100μm diameter have successfully been tented with a 10μm thick film. A DVS-bis-BCB-based laminate has been demonstrated with continued optimization and evaluation to follow.

Different responses of the melanin index to ultraviolet irradiation in relation to skin color and body site.

Few reports describe UVB irradiation-induced pigmentation responses from different skin colors or from different body sites. This study determined pigmentation changes in skin with different colors and from different body sites following 308-nm excimer laser irradiation. Ten healthy Korean adults were divided into light- and dark-skin groups, and irradiated body sites were divided into unexposed zones (UZ), intermittently exposed zones (IEZ), and frequently exposed zones (FEZ). Twenty-four areas were irradiated with a single 300-mJ/cm(2) shot delivered by an excimer laser. MIs were measured before irradiation, immediately after irradiation, and then 1 day, 3 days, 7 days, 14 days, and 21 days after irradiation. MIs declined significantly on day 1 after irradiation, particularly in light-colored skin. In the light-skin group, the MI increased from day 3 after irradiation and continued to increase for 21 days, whereas in the dark-skin group, the peak MI was reached at 7 days and declined thereafter. The peak MIs were reached at 7 days in the IEZ and FEZ and at 14 days in the UZ. Following UVB irradiation, MIs decreased, particularly in light-colored skin, before delayed tanning developed. UVB-induced pigmentation varied according to different skin colors and the body sites irradiated.

Improvement of electrical performance of InGaZnO/HfSiO TFTs with 248-nm excimer laser annealing

The influence of 248-nm KrF excimer laser annealing (ELA) with energy density between 0 and 400 mJ/cm2 on the electrical behavior of indium gallium zinc oxide (InGaZnO) thin-film transistors (TFTs) is investigated. The experimental results show that the saturation mobility and subthreshold swing are improved from 12.4 cm2/Vs and 100 mV/dec without ELA to 17.8 cm2/Vs and 75 mV/dec, respectively, by applying a 300 mJ/cm2 laser pulse after the source/drain deposition, while maintaining an almost unchanged turn-off voltage. Such improvements are attributed to the increase in the oxygen vacancies and reduction in the bulk traps in the InGaZnO channel.

The interaction of 193 nm excimer laser radiation with single-crystal zinc oxide: Generation of long lived highly excited particles with evidence of Zn Rydberg formation

In past studies, we have observed copious emissions of ionic and atomic Zn from single-crystal ZnO accompanying irradiation of single-crystal ZnO with 193-nm excimer laser irradiation at fluences below the onset of optical breakdown. The Zn+ and ground state Zn° are studied using time-of-flight techniques and are mass selected using a quadrupole mass spectrometer. Simultaneously, we have observed emitted particles that are detectable with a Channeltron electron multiplier but cannot be mass selected. It is a reasonable hypothesis that these particles correspond to a neutral atom or molecule in highly excited long lived states. We provide strong evidence that they correspond to high lying Rydberg states of atomic Zn. We propose a production mechanism involving laser excitation via a two photon resonance excitation of Zn°.

The effectiveness of excimer laser on vitiligo treatment in comparison with a combination therapy of Excimer laser and tacrolimus in an Iranian population

Objectives: Usage of 308-nm excimer laser (EL) is an effective treatment in vitiligo. As genetic predispositions along with type of skin and rate of sun exposure are known factors influencing the treatment outcomes, we tried to evaluate the treatment results of using 308 nm-excimer laser alone in comparison with the combined therapy of EL and topical tacrolimus in Iranian patients with vitiligo. Methods: We reviewed the medical files of 150 patients with vitiligo who were referred to the Behsima Laser Center between April 2012 and April 2013. Seventy five patients who received combined therapy of 308 nm EL and topical tacrolimus three times a week entered the study. Seventy-five controls with matched characteristics and who received only EL were also selected. The amount of repigmentation was estimated by an expert dermatologist and was classified in 5 ranks. Results: In the case group, 33.3% (n: 25) showed 50–75% repigmentaion and 49.3% (n:37) had more than 75% response to therapy, whereas among the patients in the control group 29.3% (n: 22) showed no repigmentation and only 8% (n: 6) demonstrated more than 75% repigmentation response. The higher efficiency of the combination therapy on repigmentation was statistically significant (P: 0.006). Conclusion: Our study shows that Iranian patients with vitiligo who received a combined treatment course with 308-nm EL and tacrolimus 0.1% experienced significantly higher levels of repigmentation in comparison with laser therapy alone.

Surface modification of a MoSiON phase shift mask to reduce critical dimension variation after exposure to a 193-nm ArF excimer laser

Abstract Introduction of a MoSi-based phase shift mask (PSM) improves photolithography resolution by causing light to shift phase by 180° thus canceling the overlap. However, when MoSiON PSM was exposed to an ArF excimer laser ( λ = 193 nm), a significant increase in patterned critical dimension (CD) was observed. It was confirmed that the CD increase resulted from oxidation progression into the MoSiON layer. In this study, N 2 O or NH 3 plasma treatment and thermal annealing in NH 3 effectively suppressed CD variation after ArF laser exposure. While the compositional ratio of Si, N, O, and Mo elements in the MoSiON layer was not changed, an increase in oxygen content only in the top 5 nm was observed. Therefore, it is concluded that slight oxidation of the top surface of MoSiON PSM by introducing either N 2 O or NH 3 plasma treatment or thermal annealing in NH 3 suppresses an increase in the patterned CD of MoSiON PSM after exposure to a 193-nm ArF excimer laser.

Excimer laser in the treatment of mycosis fungoides

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma, which typically presents as a patch or plaque in early-stage disease. Phototherapy including psoralen plus ultraviolet A and ultraviolet B are well-established treatment modalities in management of early-stage MF. Only a limited number of reports have evaluated the efficacy of 308-nm excimer laser in therapy of cutaneous T-cell lymphoma. We sought to evaluate the efficacy of 308-nm excimer laser (XTRAC, PhotoMedex, Montgomeryville, PA) in patients with stage IA to IIA MF. We reviewed the clinical and laboratory characteristics of 6 consecutive patients given the diagnosis of refractory MF who underwent treatment with excimer laser. We found that the 308-nm excimer laser is a safe and well-tolerated alternative therapy for early-stage MF. In addition, we were able to delineate criteria to help predict treatment response. Our data showed that 4 (66%) patients achieved clinical improvement (3 complete responses, 1 partial response), 1 had stable disease, and 1 had progressive disease. This was a retrospective study consisting of 6 patients. A prospective study with a larger sample size would be desirable for future studies. The use of 308-nm excimer laser in the treatment of stage IA to IIA MF showed clinical and pathological benefit for patients with isolated lesions or lesions in areas that may be difficult to treat because of anatomic location.

Microfiber interferometric acoustic transducers

Acoustic and ultrasonic transducers are key components in biomedical information technology, which has been applied in medical diagnosis, photoacoustic endoscopy and photoacoustic imaging. In this paper, an acoustic transducer based on Fabry-Perot interferometer (FPI) fabricated in a microscaled optical fiber is demonstrated. The transducer is fabricated by forming two wavelength-matched Bragg gratings into the microfiber by means of side illumination with a 193nm excimer laser. When placing the transducer in water, the applied acoustic signal periodically changes the refractive index (RI) of the surrounding liquid and modulates the transmission of the FPI based on the evanescent-field interaction between the liquid and the transmitting light. As a result, the acoustic signal can be constructed with a tunable laser whose output wavelength is located at the slope of the inteferometric fringes. The transducer presents a sensitivity of 10 times higher than the counterparts fabricated in conventional singlemode fibers and has great potential to achieve higher resolution for photoacoustic imaging due to its reduced diameter.

Producing regenerated gratings in hydrogen-loaded single mode fiber by heat treatment

The fiber Bragg grating (FBG) is a passive optical fiber component with the refractive index modulated along the fiber length and has been widely applied in fiber sensing systems. High-temperature stable fiber gratings are promising for uses at high temperatures and attract extensive attention. In this paper, FBGs were inscribed in hydrogen loaded standard single mode fibers with the 248-nm excimer laser, and regenerated gratings were obtained through heat treatment. The shift of the central wavelength of the regenerated FBG had a good linearity with temperature, and the reflectivity of the regenerated FBG could almost keep unchanged at 800 °C.

Innovative treatment option for moderate to severe generalized psoriasis using 308-nm excimer laser, clobetasol spray, and calcitriol ointment

Innovative treatment option for moderate to severe generalized psoriasis using 308-nm excimer laser, clobetasol spray, and calcitriol ointment

Supraerythemogenic excimer laser in combination with clobetasol spray and calcitriol ointment for the treatment of generalized plaque psoriasis: Interim results of an open label pilot study

Background: The combination of phototherapy and topical therapy is one of the most widely used treatment modalities for moderate to severe psoriasis. The development of targeted phototherapy with excimer laser and new topical spray formulations has made these therapies both more convenient and more effective. In this open label pilot study, we aim to assess the efficacy of combination therapy using 308-nm excimer laser, clobetasol propionate spray and calcitriol ointment for the treatment of moderate to severe generalized psoriasis.Methods: In this 12-week study, patients with moderate to severe psoriasis received twice weekly treatment with XTRAC® Velocity 308-nm excimer laser combined with clobetasol propionate twice daily followed by calitriol ointment twice daily.Results: To date, 21 patients have completed the protocol. By week 12, 76% of the patients had a reduction in Psoriasis Area and Severity Index by at least 75% (PASI-75) and 52% had a Physicians Global Assessment of “clear” or “almost clear”.Conclusions: Excimer laser therapy combined with an optimized topical regimen that includes clobetasol spray followed by calictriol ointment appears to be an effective treatment for moderate to severe generalized psoriasis that avoids the risk of serious internal side effects associated with many systemic agents.

Ablation behaviour of allanites during U–Th–Pb dating using a quadrupole ICP-MS coupled to a 193 nm excimer laser

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been employed for U–Th–Pb geochronology of allanite, using various analytical parameters. Opinions diverge on analytical protocols and data reduction, and particularly, on the possibility of using non-matrix-matched standards and samples to obtain accurate and precise ages. In this study, ablation experiments were carried out in spot mode using an ArF 193nm excimer laser coupled to a quadrupole ICP-MS, in order to characterise the ablation behaviour of allanite under various fluence (4, 7.8 and 12J/cm2) and ablation rate conditions (4, 8 and 12Hz). The U–Th–Pb data were compared to the Plešovice zircon (337.13±0.37Ma) in order to investigate the effects of the different matrices. The ratio-of-the-mean intensities method was used for data reduction. Analyses in spot mode at low frequency and fluence provide accurate and precise allanite 206Pb/238U and 208Pb/232Th ages, using a matrix-matched external standard. Matrix effects between allanites with different ages (30.1 to 417Ma), common 208Pb (0.5–33%) and 206Pb (5.8–90%) proportions, and FeOtotal (11.5–16.1%) and REE+Th (0.52–0.90apfu) compositions do not affect the age accuracy. The difference of mass bias correction coefficients between allanites and zircon shows evidence of matrix effects, which are often responsible for systematic errors on ages. Matrix-matched standardisation with an allanite standard is required for precise U–Th–Pb allanite ages. Even though laser-induced elemental fractionation can be minimised for non-matrix-matched standards and samples, other sources of matrix effects still affect age accuracy and precision.

Optical signatures of photoinduced Zn vacancies in ZnO single crystal

193-nm excimer laser interaction with ZnO single-crystal at 0.05–500 KW/cm2 intensities is investigated under ultra high vacuum conditions by time resolved photoluminescence (PL) spectroscopy. A dominant 3.18 eV PL emission band at 295 K is observed. This band shows unusually long 0.52 ± 0.01 μs lifetime, indicating a defect mediated emission mechanism. The demonstrated negative thermal quenching for this band confirms its free electron to acceptor type transition. The involved acceptor is attributed to zinc vacancy with ∼100 meV shallow acceptor state. This study finds that 193-nm interactions produce Zn vacancies in transient states at 0.05–50 KW/cm2 excitation intensities and in stable state at 500 KW/cm2 or above intensities. The transient zinc vacancy production at such low intensities further validates the Frenkel pair creation as mechanism for creating these defects in ZnO single-crystal.

308nm excimer laser in dermatology.

308nm xenon-chloride excimer laser, a novel mode of phototherapy, is an ultraviolet B radiation system consisting of a noble gas and halide. The aim of this systematic review was to investigate the literature and summarize all the experiments, clinical trials and case reports on 308-nm excimer laser in dermatological disorders. 308-nm excimer laser has currently a verified efficacy in treating skin conditions such as vitiligo, psoriasis, atopic dermatitis, alopecia areata, allergic rhinitis, folliculitis, granuloma annulare, lichen planus, mycosis fungoides, palmoplantar pustulosis, pityriasis alba, CD30+ lympho proliferative disorder, leukoderma, prurigo nodularis, localized scleroderma and genital lichen sclerosus. Although the 308-nm excimer laser appears to act as a promising treatment modality in dermatology, further large-scale studies should be undertaken in order to fully affirm its safety profile considering the potential risk, however minimal, of malignancy, it may impose.