He-Ne Research Articles

Assessment of DNA mutagenicity induced by He-Ne laser using Salmonella typhimurium strains.

Helium-neon (He-Ne) laser mutagenesis is widely used in microbiology and plant breeding. In this study, two frameshift mutant representative strains of Salmonella typhimurium TA97a and TA98 and two base pair substitution types TA100 and TA102 were employed as model microorganisms to assess DNA mutagenicity induced by He-Ne laser (3J·cm-2·s-1, 632.8nm) for 10, 20, and 30min. The results revealed that the optimal laser application was 6h in the mid-logarithmic growth stage. Low-power He-Ne laser for short treatment inhibited cell growth, and continued treatment stimulated the metabolism. The effects of the laser on TA98 and TA100 were the most prominent. Sequencing results from 1500 TA98 revertants showed that there were 88 insertion and deletion (InDel) types in the hisD3052 gene, of which the InDels unique to laser were 21 more than that of the control. Sequencing results from 760 TA100 revertants indicated that laser treatment created Pro (CCC) in the product of the hisG46 gene more likely to be replaced by His (CAC) or Ser (TCC) than by Leu (CTC). Two unique non-classical base substitutions, CCC → TAC and CCC → CAA, also appeared in the laser group. These findings will provide a theoretical basis for further exploration of laser mutagenesis breeding. KEY POINTS: • Salmonella typhimurium served as model organism for laser mutagenesis study. • Laser promoted the occurrence of InDels in the hisD3052 gene of TA98. • Laser promoted the occurrence of base substitution in the hisG46 gene of TA100.

Quantification of total polyphenol content in wine lees by conventional optical and photoacoustic spectroscopy

The He-Ne laser (632.8 nm) and photoacoustic spectroscopy (PAS), a variant of the photothermal methods, were combined with the Folin-Ciocalteu colorimetry method to determine total phenolics in wine lees. Utilising this method we found that the total polyphenol content of the nine selected wine lees varied from 1305 to 3907 mg/L. The gallic acid equivalent was determined by means of spectrophotometry using 765 nm as the analytical wavelength. The original Folin-Ciocalteu colorimetry assay was modified for the PAS measurements. Since the PAS does not need dilution, the filtration steps and the Folin-Ciocalteu reagent were used directly on the wine lees samples. Using the original colour reaction process and the modified reaction, the PAS showed linear behaviour between the total polyphenol content and the PA signal; the results of which gave determination coefficients of 0.9946 and 0.9936, while the limit of detection was 232.6 mg/L in both cases.

Absolute distance measurement using frequency sweeping interferometry with large swept range and target drift compensation

Frequency sweeping interferometry (FSI) is an attractive absolute distance measurement (ADM) method because of the advantages of large unambiguity range, simple structure and excellent flexibility. By using a reference interferometer (RI), the calibration of the frequency sweeping range in FSI can be avoided, and the complexity and cost of the system can be further reduced. Then, the measurement accuracy is associated with the accuracy of phase demodulation, the range of frequency sweeping and the compensation of target drift. In this paper, ADM using FSI with large swept range and target drift compensation is presented. A frequency stabilized HeNe laser that travels along the same optical path with the swept source laser was employed to monitor the target drifts of the measurement interferometer and RI. Interference phases of the corresponding interferometers were extracted simultaneously using phase generated carrier demodulation technique, and an accuracy better than 1° was verified by nanometer displacement measurement. Comparative experiments of ADM at a distance of ∼4.5 m with different swept ranges before and after target drift compensation were carried out, and the results demonstrated that larger swept range and target drift compensation could greatly improve the stability and accuracy of measurement.

The bactericidal effects of 632.8 nm He-Ne laser on Staphylococcus aureus colonies

The bactericidal effect of 632.8 nm low level laser has been studied in order to point out both the effective power and laser exposure time on Staphylococcus aureus, which is reported to be involved in several dermatology problems. Low level laser has been reported to be useful for infected wounds, tissue necrosis, nerve injury, osteoarthritis or other chronic pain syndromes. Numerous studies have been conducted to quantify the effective laser parameters, i.e. dose, power, and exposure time, which ultimately leads toward clinical implementation. Staphylococcus aureus bacteria colonies were exposed to laser doses with powers of both 1 and 3 mW at different exposure times varies between 3 to 30 minutes. The bacterial colonies were isolated from a patient with inflamed wounds. Two sets of bacterial colonies were prepared to be exposed to laser beam. Next, the bacterial colonies were compared before and after exposing them to laser doses. The results showed that laser sessions have reduced the number of the bacterial colonies for both doses; 1 and 3 mw at the different exposure times and concentrations. The results revealed significant dose dependent bactericidal effects of He-Ne laser on Staphylococcus aureus at 3 mW for 30 minutes, which was found to be more effective in reducing the amount of bacteria to the less than 2% of its initial count. The results exhibited the reduction of the number of colonies as a function of exposure time. Appropriate doses of 632.8 nm can kill Staphylococcus aureus, suggesting that a similar effect may be used in clinical cases of bacterial infection.

Effect of helium-neon laser irradiations on the in vitro culture of Vanilla planifolia jacks

Effect of helium-neon laser irradiations on the in vitro culture of Vanilla planifolia jacks

Prophylaxis of postoperative hypoparathyroidism in thyroid surgery.

There are a number of thyroid gland diseases that require surgical treatment. Therefore, it is important to improve the surgical approaches and treatment tactics in patients that need such surgery. To provide an algorithm to prevent parathyroid gland damage during surgery. This work was based on treatment results of 226 patients with different thyroid diseases. All patients received extrafascial surgical interventions using modern methodological approaches. For prevention of postoperative hypoparathyroidism, we used the "stress-test", 5-aminolevulenic acid, and a method of double visual-instrumental registration of photosensitizer-induced fluorescence of parathyroid glands. Transient hypoparathyroidism was registered in four (1.8%) cases after surgery. Permanent hypocalcemia in patients was not recorded. Autotransplantation of parathyroid gland was required only in one case (0.44%). A deficiency or low level of vitamin D was detected in 35% of the cases, and in the majority of those cases, it was due to secondary hyperparathyroidism. The deficiency was corrected with the administration of vitamin D in all cases. In 10.17% (23 patients) of cases, there was no proper visual glow effect after administration of 5-aminolevulinic acid (5-ALA), which required proceeding to the second part of the proposed method (a helium-neon laser and registration of fluorescence using a laser spectrum analyzer). The proposed methodological approach allows prevention of persistent hypoparathyroidism and reduces the frequency of transient hypoparathyroidism and other complications in surgical treatment of patients with various thyroid gland diseases.

Synthesis, crystal growth and characterization of piperazinium 5-nitrosalicylate (P5NS) single crystal for nonlinear optical (NLO) applications

A single crystal of Piperazinium 5-nitrosalicylate (P5NS) was grown by using slow evaporation solution technique (SEST). The structural analysis (crystal system & cell parameter) of the grown P5NS crystal was examined by single crystal XRD and it exposed that the P5NS crystal has a crystal triclinic system and space group (P-1). Using powder XRD analysis, miller index and (h k l) planes were identified. The P5NS crystal has a sharp cutoff wavelength around 380 nm and is transparent in UV region. The FTIR analysis was investigated on the P5NS crystal to find out the P5NS functional groups. The thermogravimetric and differential thermal analysis illustrate that the P5NS crystal is thermally stable upto 255 °C. Further increase in the temperature resulted in decomposition of P5NS. The etch pit density of P5NS crystal has been calculated by using the chemical etching analysis. The Photoconductivity study reveals that the grown PMC crystal has positive photoconductive nature. The electrical properties, dielectric constant and dielectric loss were determined. The laser damage threshold (LDT) analysis was investigated by Nd: YAG laser and the wavelength of laser is 1064 nm. Intermolecular interactions of P5NS is executed by the Hirshfeld surface analysis. The NLO susceptibility (χ(3)) was calculated by the Z-scan method using the source of He-Ne laser, whose wavelength is 632.8 nm.

A simple and low-cost setup for part per billion level frequency stabilization and characterization of red He-Ne laser

This work describes the frequency stabilization of a dual longitudinal mode, red (632.8 nm) He-Ne laser, implemented using an open source low-cost microcontroller (Arduino Uno) and its performance characterization using a simple interferometric method. Our studies demonstrate that frequency stability up to 0.42 MHz (3σ, 17 h) can be achieved using this setup. This simple and low-cost system can serve as an excellent part per billion level frequency reference for high-resolution spectroscopy based applications.

Effects of intravascular photobiomodulation on cognitive impairment and crossed cerebellar diaschisis in patients with traumatic brain injury: a longitudinal study

The association between intravascular photobiomodulation (iPBM) and crossed cerebellar diaschisis (CCD) and cognitive dysfunction in patients with traumatic brain injury (TBI) remains unknown. We postulate that iPBM might enable greater neurologic improvements. The objective of this study was to evaluate the clinical impact of iPBM on the prognosis of patients with TBI. In this longitudinal study, patients who were diagnosed with TBI were recruited. CCD was identified from brain perfusion images when the uptake difference of both cerebella was > 20%. Thus, two groups were identified: CCD( +) and CCD( −). All patients received general traditional physical therapy and three courses of iPBM (helium–neon laser illuminator, 632.8 nm). Treatment assemblies were conducted on weekdays for 2 consecutive weeks as a solitary treatment course. Three courses of iPBM were performed over 2–3 months, with 1–3 weeks of rest between each course. The outcomes were measured using the Rancho Los Amigos Levels of Cognitive Functioning (LCF) tool. The chi-square test was used to compare categorical variables. Generalized estimating equations were used to verify the associations of various effects between the two groups. p < 0.05 indicated a statistically significant difference. Thirty patients were included and classified into the CCD( +) and CCD( −) groups (n = 15, each group). Statistics showed that before iPBM, CCD in the CCD( +) group was 2.74 (exp 1.0081) times higher than that of CCD( −) group (p = 0.1632). After iPBM, the CCD was 0.64 (exp-0.4436) times lower in the CCD( +) group than in the CCD( −) group (p < 0.0001). Cognitive assessment revealed that, before iPBM, the CCD( +) group had a non-significantly 0.1030 lower LCF score than that of CCD( −) group (p = 0.1632). Similarly, the CCD( +) group had a non-significantly 0.0013 higher score than that of CCD( −) after iPBM treatment (p = 0.7041), indicating no significant differences between the CCD( +) or CCD( −) following iPBM and general physical therapy. CCD was less likely to appear in iPBM-treated patients. Additionally, iPBM was not associated with LCF score. Administration of iPBM could be applied in TBI patients to reduce the occurrence of CCD. The study failed to show differences in cognitive function after iPBM, which still serves as an alternative non-pharmacological intervention.

RESEARCH ON CLINICAL MANIFESTATIONS, CORRELATIVE FACTORS AND EVALUATING THE RESULTS OF TOPICAL TREATMENT OF ZONA WITH HE-NE LASER COMBINATION AT CAN THO DERMATO-VENEREOLOGY HOSPITAL IN 2021

Background: Shingles is a common skin infection, caused by the latent Varicella zoster virus in the paraspinal cranial nerve ganglia, when there are favorable factors such as immunosuppression makes the virus active again. The disease greatly affects the patient's quality of life. Objectives: Survey to determine clinical manifestations, correlative factors and evaluate the results of topical treatment of herpes zoster with He-Ne laser combination at Can Tho DermatoVenereology Hospital in 2021. Methods: Cross-sectional descriptive study with 75 Zona patients who were treated according to the usual regimen and combined with local He-Ne laser at Can Tho Dermato-Venereology Hospital. Results: The disease that occurs in the age group over 60 years old is the most common (56%). Pain was found in 100% of patients. The vesicle lesions accounted for the highest rate (84%), the most commonly affected area was trunk 38.7%. Mild level accounted for 57.3%. The group of patients with more than 5 days of illness had a longer hospital stay (42.9%). After treatment with He-Ne laser, 66.7% had good treatment results. Conclusions: Herpes zoster disease occurs at any age, but mainly in the elderly with vesicles and pain in most of the patients, commonly on the trunk and head-face-neck area. Attention should be paid to the time before admission, the state of co-infection because they reduce the response to treatment. The combination of He-Ne laser with conventional regimens helped to cure and effectively reduce pain in Herpes Zoster patients.

DYNAMICS OF INTESTINAL CONTENT FLUCTUATIONS ANASTOMOSED SMALL INTESTINE LOOPS AS MARKER IN DIAGNOSIS OF DUMPING SYNDROME OF DIFFERENT SEVERITY IN GASTRIC CANCER PATIENTS AFTER GASTRECTOMY

The aim: to study the effectiveness of the method of daily fibroesophagoejunoscopy in determining the number of pellets of intestinal contents in the newly created anatomical-physiological complex and related functional disorders, accompanied by the manifestation of clinical symptoms of dumping syndrome of varying severity. Materials and methods. The method of fibrogastroscopic examination was by 190 patients with gastric tract after gastrectomy carried out. All patients were diagnosed with dumping syndrome of varying severity. The study showed that the severity of clinical manifestations of dumping syndrome depends on the number of intestinal contents in the newly created anatomical-physiological complex depending on the time of day. For proof of body, observing the stage, 30 patients underwent a modified esophagogastroscopic examination method, which was proposed by us – daily fibroeophagoeunoscopy, as well as histological and histochemical studies to detect inflammatory changes in anastomosed loops of the small intestine. To determine the dependence of clinical manifestations of dumping syndrome on the number of intestinal pellets, all patients underwent intracavitary intestinal laser therapy with helium-neon laser ULF-01. Results. When analyzing and comparing the data obtained during daily fibroesoeunoscopy with the clinical manifestations of dumping syndrome of varying severity, it was found, that at different periods of the day the intensity of intestinal casting in anastomosed loops of the small intestine and clinical manifestations of the disease differ significantly. It was established, that in the morning hours, at all degrees of severity of dumping syndrome, there was a minimum number of pellets of intestinal contents in the newly created anatomical complex and, accordingly, there were minimal clinical manifestations of the disease. The study also showed that the increase in clinical symptoms in patients with dumping syndrome is clearly precisely in the daytime manifested. Conclusions. The findings suggest that daily fibroesophagoeunoscopy is a pathognomonic method for diagnosing dumping syndrome in gastric cancer patients after gastrectomy. The method made it possible to establish that the severity of clinical manifestations depends on the number of casts of intestinal content and the time of its exposure in the newly created anatomical complex. The clinical symptoms of dumping syndrome are most in the daytime pronounced. The method also made it possible to determine that the most effective time for laser therapy is the morning period.

Linear and Nonlinear Optical Properties of PVA:SA Blend Reinforced by TiO2 Nanoparticles Prepared by Flower Extract of Aloe Vera for Optoelectronic Applications

In this study, a polyvinyl alcohol–sodium alginate blend, PVA:SA 3:1 (w:w), was doped with different contents of TiO2 nanoparticles (NPs) prepared by aloe vera leaf extract to form the investigated nanocomposites. The nonlinear parameters of third-order susceptibility (χ(3)) and refractive index (n2) were detected by using UV-Vis spectroscopy and Z-scan techniques. Some different optical parameters were also determined, including the refractive index (n), optical dielectric parameters, volume and surface energy loss functions, and some others. The best solar skin protection factor (SSPF) was investigated by 5 wt.% of TiO2 NPs doped in PVA:SA 3:1, which was about 84.6% compared to the corresponding value of the host blend (41%). The studied nanocomposites were examined for their utility in the optical limiting of CUT-OFF laser filters utilizing a continuous He-Ne laser working at 632.2 nm. As a result, our finding demonstrated that TiO2 NPs doped in the host blend of PVA:SA positively influences a laser light blocking for the investigated laser source. Using the estimated gap energies values, different models were used to deduce theoretical values of the linear refractive index (n). The presence of Ti peaks in the EDX spectrum confirmed the doping of TiO2 NPs in the nanocomposites. SEM showed that the TiO2 NPs are homogeneously dispersed through the host blend with some agglomerates. XRD spectra showed that the values of the lattice strain εstr. detected at 2ϴ = 19.78° are 0.058, 0.055, and 0.060, corresponding to 1, 3, and 5 wt.% of TiO2 NPs doped in the PVA:SA blend.

SOME FACTORS RELATED TO THE DURATION OF INPATIENTS TREATMENT OF HERPES ZOSTER BY HE-NE LASER THERAPY AT CAN THO DERMATO-VENEREOLOGY HOSPITAL

Background: Shingles is caused by the Varicella-Zoster virus. The duration of hospitalization prolong will increase the risk of superinfection, costs for treatment, and quality of life. Objectives: (1) To describe clinical manifestations of herpes zoster inpatients at Can Tho Dermato-Venereology Hospital. (2) To survey some related factors related to the duration of hospitalization of herpes zoster by He-Ne laser therapy at Can Tho Dermato-Venereology Hospital. Materials and methods: the cross-sectional study on all shingles patients admitted to Can Tho Dermato-Venereology Hospital during the study period. Results: The proportion of group patients &gt;60 years old was 54.9% higher than the group of patients ≤60 with 45.1%. Most shingles patients had secondary school degrees with 69%. The rate of patients admitted to the hospital early ≤5 days after symptom onset was 72.6%. Patients hospitalized for ≤7 days accounted for 77%. Patients with mild illness had the highest rate with 58.4%, and the rate of medium and severe illness with 36.3% and 5.3% respectively. Most patients had superinfection with 72.6%. The group of patients admitted to the hospital early ≤5 days had a shorter duration of hospitalization than the group of patients admitted to the hospital late after 5 days. In the patient's group with superinfection and more severe disease, the duration of hospitalization was longer than in the patient’s group without superinfection and the severity of the disease was milder. All differences were statistically significant, p&lt;0.05. Conclusion: Early treatment with He-Ne laser therapy helps to improve the severity of the disease and the state of superinfection and shorten the patient's hospital stay.

Thermal Annealing Effects on the Raman and Photoluminescence Properties of Mono and Few-Layer MoS&lt;sub&gt;2&lt;/sub&gt; Films

In this study, we report that the thermal treatment effects on the Raman and photoluminescence (PL) spectra of mono and few-layer MoS2 films by annealing in the vacuum and air at 300°C, respectively. The MoS2 film samples were prepared on silicon substrate by exfoliating from a bulk MoS2 crystal with a micromechanical exfoliation. For characterization of structural properties of the MoS2 films and identification of the Raman active modes, Raman spectrometer equipped with a He-Ne laser source and an optical microscope has been used. The results show that the vacuum annealing 7L MoS2 decreases the Full Width at Half Maximum (FWHM) of the Raman active modes as E12g, A1g and the vacuum annealing 1L MoS2 increases the PL intensity and peak energy, for 60% and 13.3meV, respectively also air annealing bilayer MoS2 increased the PL intensity (IA) and peak energy (EA), respectively for 85% and 15.4 meV (300°C for 40 min). After thermal annealing (vacuum and air), we observe that the indirect bandgap of the few-layer MoS2 was changed.

High-Speed Optical Diagnostics of a Supersonic Ping-Pong Cannon.

The traditional ping-pong cannon (PPC) is an educational apparatus that launches a ping-pong ball down an evacuated pipe to nearly sonic speeds using atmospheric pressure alone. The SSPPC, an augmented version of the PPC, achieves supersonic speeds by accelerating the ball with greater than atmospheric pressure. We provide instructions for the construction and utilization of an optimized PPC and SSPPC. Optical diagnostics are implemented for the purpose of investigating the cannon dynamics. A HeNe laser that is sent through two acrylic windows near the exit of the pipe is terminated on a photoreceiver sensor. A microprocessor measures the time that the beam is obstructed by the ping-pong ball to automatically calculate the ball's velocity. The results are immediately presented on an LCD display. An optical knife-edge setup provides a highly sensitive means of detecting shock waves by cutting off a fraction of the HeNe beam at the sensor. Shock waves cause refraction-induced deflections of the beam, which are observed as small voltage spikes in the electrical signal from the photoreceiver. The methods presented are highly reproducible and offer the opportunity for further investigation in a laboratory setting.

A simple and low-cost setup for part per billion level frequency stabilization and characterization of red He-Ne laser

A simple and low-cost setup for part per billion level frequency stabilization and characterization of red He-Ne laser

Raman spectroscopy of lithium niobate (LiNbO3) − Sample temperature and laser spot size effects

The Raman spectrum of lithium niobate (LiNbO3) was investigated in the 83–823 K temperature range and as a function of different laser spot sizes. The measurements considered a Z-cut (congruent, undoped) LiNbO3 crystal, HeNe laser excitation (632.8 nm photons), and the zx,xyz¯ geometry. The main LiNbO3-related phonon modes were identified and analyzed in terms of their peak position (ω) and linewidth (γ), according to which it was possible to identify the contributions originating from anharmonic phonon-coupling and thermal lattice-expansion processes. The analyses of the temperature-dependent ωT and γT data took into account the 3- and 4-phonon model and the experimental Grüneisen and linear thermal expansion coefficients − as available from literature. Among all phonon modes of LiNbO3, the A1(TO4) mode presented a peculiar behavior (at room temperature) that depends on the laser spot size during the Raman measurements. The development of this forbidden mode has been associated with the congruent-photorefractive nature of LiNbO3 as well as with small variations in the geometry of polarization (as a result of changes in the laser spot size).

Structural, particle size distribution, and electrochemical behavior of double perovskite oxide doped Ce0.8Sm0.2O1.9 for intermediate temperature solid oxide fuel cells

Double perovskite SmBa0.5Sr0.5Co2O5+δ(70%)+Ce0.8Sm0.2O1.9(30%) as SBSC70+SDC30 cathode was fabricated using solid-state reaction technique and investigated as cathode material for solid oxide fuel cells operating at intermediate temperature (IT-SOFC). This work aims to determine the effect of SDC electrolyte doping into double perovskite cathodes on SOFC performance. LS-POP carried out particle size distribution analysis, and the equipment operates on a light source (HE-Ne laser) basis. XRD was used to determine the structure of the cathode powder, and SEM was used to analyze the microstructure morphology. Symmetrical cells were tested using a potentiostat Voltalab PGZ 301. The distribution of particle size for the SBSC70+SDC30 cathode was in the range of 1.41-2.03 µm. The polarization resistance (Rp) value of SBSC70+SDC30 cathode decreases with increasing temperature from 1.22 cm2 at 600°C to 0.21 cm2 at 800°C. The SBSC70+SDC30 activation energy (Ea) for Rp was 117. 3 kJ mol−1. From the overall results, double perovskite SBSC70+SDC30 cathode has potential as a cathode of medium temperature SOFC cells.

EFFECT OF VOLATILE OILS MIXTURE AND LASER RADIATION ON LIPID OXIDATION AND SHELF LIFE OF BEEF SAUSAGE DURING CRYOPRESERVATION

The aim of this research is to study the chemical components of cinnamon, rosemary, and clove volatile oils by GC/Mass as well as the antioxidant activity of these oils and their mixture by DPPH scavenging to select the best volatile oil or mixture for preparing beef sausage treated with laser rays (Helium-Neon laser wavelength 632.8 nm for 9 min for each side). Also, to study the effect of volatile oils mixture at 500 ppm and laser radiation on lipid oxidation and shelf-life of beef sausage during cold storage. Results indicated that 23, 10, and 18 compounds were identified from cinnamon, rosemary, and clove which represented 97.26, 98.50 and 98.80 %, respectively. Cinnamaldehyde, 1, 8 Cineole, and Eugenol were the most abundant chemical compounds in cinnamon, of cinnamon, rosemary, and clove volatile, respectively. Volatile oils mixture had significantly higher antioxidant activity than each volatile oil individual but significantly lowers than BHT as a synthetic antioxidant substance at all studied concentrations. Lipid oxidation (peroxide value, thiobarbituric acid, and acid value) of sausage treatments were not affected significantly by laser irradiation or volatile oils mixture immediately after processing (at zero time) but affected (p&lt;0.5) during cold storage. Sausage treated with both laser irradiation and volatile oils mixture had significantly lower peroxide value, thiobarbituric acid and acid value than other sausage treatments at any time of cold storage. Also, laser irradiation plus the addition of volatile oils mixture caused high storage stability which increase the shelf-life of sausage to 20 days at 4±1ºC compared with sausage treated with volatile oils mixture only (15 days), sausage treated with laser rays only (10 days) and control sample (5 days).

Laser and light therapy combined with topical minoxidil for alopecia areata: a systematic review and meta-analysis of randomized controlled trials.

We aim to evaluate the clinical efficacy and safety of using laser and light combined with topical minoxidil for alopecia areata. We searched PubMed, Embase, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), VIP database, and Wanfang Data from their inception to September 18, 2022. The risk of bias of the included RCTs was assessed by the Cochrane Collaboration tool. RevMan 5.3 software and Stata 14.0 software were used to perform the statistical analysis. The GRADE system assessed the quality of evidence. Ten studies were enrolled finally. The results of the meta-analysis showed that compared with topical minoxidil alone, the 308-nm excimer laser/light or He-Ne laser combined with topical minoxidil could reduce the SALT (Severity of Alopecia Tool) score (MD= -5.88, 95% CI [-9.79, -1.98], P=0.003). Whether fractional CO2 laser (RR=1.29, 95% CI [1.14, 1.46], P<0.0001), 308-nm excimer laser/light (RR=1.32, 95% CI [1.12, 1.55], P=0.001), He-Ne laser (RR=1.69, 95% CI [1.07, 2.69], P=0.03), or NB-UVB (RR=1.35, 95% CI [1.07,1.70], P=0.01) combined with topical minoxidil may improve the treatment response rate, comparing with topical minoxidil only. The recurrence rate of laser and light combined with topical minoxidil was lower than that of the minoxidil alone group (RR=0.54, 95% CI [0.31, 0.93], P=0.03) when follow-up time was 1 year. In addition, the incidence of adverse events including irritant contact dermatitis, erythema, desquamation, pain, and pruritus was no significant difference between the two groups (RR=1.50, 95% CI [0.95, 2.36], P=0.08). The level of evidence for outcomes was classified as very low to moderate. Based on the available evidence, laser and light combined with topical minoxidil therapy may be effective and safe for alopecia areata. However, more high-quality trials are required for comprehensive analysis and further verification.