Dual Wavelength Research Articles

Green spectrophotometric approaches applied to tertiary mixture for management of common cold and COVID-19 symptoms

Recently, cold and cough dosage forms have gained significant attention due to their use in the supportive protocols for managing COVID-19 symptoms. In this study, a pharmaceutical formulation containing Paracetamol (PAR), Guaifenesin (GUA), and Phenylephrine hydrochloride (PHE) was investigated for spectral resolution and quantification using advanced spectrophotometric methods. The spectra of these components were significantly overlapped and present in their combined tablet in a challenging ratio of 250:100:5 for PAR, GUA, and PHE, respectively. The established approaches were employed for the simultaneous determination of these drugs in their pharmaceutical formulation without interference from matrix excipients. The study involved various manipulation steps, allowing each component in the combination to be analyzed by more than one approach. Integrating these methods with smart mathematical techniques, the issue of spectral data overlap was resolved without the need for preliminary separation steps. The developed methods are dual wavelength, first derivative, derivative ratio, ratio difference, constant center coupled with spectrum subtraction, and constant multiplication paired with spectrum subtraction. The proposed methods were linear over the concentration range of 3.0–35.0 μg/mL for GUA and 3.0–30.0 μg/mL for PHE. While the PAR ranges for the first derivative and constant multiplication methods were 2.5–35.0 μg/mL and 2.5–25.0 μg/mL, respectively. Excellent linearity of the suggested methods was demonstrated by the high correlation coefficients (R2), ≥ 0.9998 for all the tested compounds. These methodologies were validated according to ICH guidelines. Validation results demonstrated excellent accuracy, with recovery percentages ranging from 98 to 102 %, and precision, with RSD values less than 2 %. The obtained results were statistically compared with the official ones using F-test, Student’s t-test, and one-way ANOVA, revealing no significant differences. The proposed methods are accurate, green, smart, fast, and cost-effective. Their compliance with Green Analytical Chemistry principles was evaluated and compared to a published method using various tools to enable a more holistic evaluation from different perspectives. The promising results revealed that the investigated methods are superior green alternatives for routine analysis of the cited drugs in laboratories with limited resources and without access to expensive instruments.

Potential of Near-Infrared Optical Techniques for Non-invasive Blood Glucose Measurement: A Pilot Study

BackgroundDiabetes mellitus manifested by escalated blood glucose, demands periodic or continuous glucose monitoring in the pursuit of improved control, optimal management, and appropriate medication. The existing state-of-the-art for blood glucose estimation are invasive methodologies necessitating the acquisition of blood sample through either a finger-stick or venipuncture. MethodsWe propose a dual Near-infrared wavelength integrated in a 3D printed enclosure as the optical prototype for non-invasive glucose estimation. We acquired data from both diabetic and healthy subjects with the developed system and subsequently validated the system. ResultsThe system demonstrated commendable clinical accuracy, as evidenced by the alignment of data pairs representing actual blood glucose levels and blood glucose levels predicted by our optical system within the A+B zones of the Parkes error grid and zones of no-risk and lower risk as defined by the surveillance error grid. We achieved compliant pairs percentage of 95.6%, which satisfies the accuracy requirements of the blood glucose monitoring surveillance study. The mean absolute percentage error attained with the proposed device (5.99%) was significant in predicting the blood glucose. ConclusionWe successfully deployed the NIR wavelengths functionality as the promising approach for glucose monitoring, offering new possibilities for improved medical interventions.

Specialized greenness sustainability tools for evaluation of the spectrophotometric methodologies greenness: spectral signal manipulation for resolving the interfering telmisartan and metoprolol succinate spectra in their bulk and pharmaceutical formulation.

Hypertension is a leading cause of cardiovascular mortality, often accompanied by complications such as arrhythmia and stroke. This silent killer requires a multifaceted pharmacological approach for effective management. This article presents new, environmentally friendly spectrophotometric methods for simultaneous quantification of telmisartan (TER) and metoprolol succinate (MTR) in laboratory prepared mixtures and pharmaceutical formulations. The suggested methodologies include the following: area under the curve method (AUC) utilizing area at specific wavelength ranges 228 -233 nm (λ1 – λ2) and 240 – 245 nm (λ3 – λ4) for each analyte and Fourier self-deconvolution method (FD) depending on built-in function to address spectral interferences. In addition, the induced dual wavelength method (IDWL) employing equality factors to obtain absorbance differences at designated wavelengths, ratio difference method (RD) utilizing divisor-based ratio spectra where the utilized divisors were TER 40 μg/mL and MTR 90 μg/mL, and ratio derivative method (RDV) generating spectra through first derivative application that was measured at 266 nm and 246 nm for TER and MTR, respectively. These methods offer green alternatives for the accurate and precise determination of TER and MTR with exceptional linearity of 3 – 45, and 15 – 200 μg/mL for TER and MTR, respectively. Furthermore, the methods showed a coefficient of determination exceeding 0.9995 and good detection and quantification levels. A comprehensive greenness assessment, employing five distinct evaluation tools, confirmed the reduced environmental impact of the proposed methods in terms of waste generation, chemical consumption, and instrument safety. Successful analysis of pharmaceutical formulations and laboratory prepared mixtures containing different TER and MTR ratios confirmed the validity of the proposed methods. Standard addition studies further supported these findings, and the statistical results were comparable to those obtained using a reference method.

Lipid nanoparticle properties explored using online asymmetric flow field-flow fractionation coupled with small angle X-ray scattering: Beyond average characterisation

This study employs asymmetric flow field-flow fractionation online coupled with small angle X-ray scattering at a synchrotron beamline, along with multiple downstream detectors, including multi-angle light scattering, dual wavelength UV and dRI. This setup enables size-resolved characterization of lipid nanoparticles, allowing for a detailed comparison between empty and cargo-loaded lipid nanoparticles intended for nucleic acid delivery. Batch-mode characterization techniques, including cryogenic transmission electron microscopy and dynamic light scattering, alongside collection of fractions for offline characterization with liquid chromatography-charged aerosol detection, allowed for determination of the particle morphology, hydrodynamic radius, and the lipid composition over the size distribution. Cargo-containing and empty lipid nanoparticles show differences in density, and loaded particles exhibit a broader size distribution and a higher frequency of blebs at the surface. Both samples consist of spherical core–shell structured particles, with no distinguishable internal structure. A pivotal finding, often assumed until now, is that the mole fraction of each individual lipid component closely matches the original formulation. This work contributes to a more detailed understanding of lipid nanoparticles, supporting their continued development and rational design in medical applications.

Estimating ice water content for winter storms from millimeter-wavelength radar measurements using a synthesis of polarimetric and dual-frequency radar observations

Abstract The potential of millimeter-wavelength radar-based Ice Water Content (IWC) estimation is demonstrated using a Ka-band Scanning Polarimetric Radar (KASPR) for the U.S northeast coast winter storms. Two IWC relations for Ka-band polarimetric radar measurements are proposed: one that uses a combination of the radar reflectivity Z and the estimated total number concentration of snow particles Nt and the other based on the joint use of Z, specific differential phase KDP, and the degree of riming frim. A key element of the algorithms is to obtain the “Rayleigh-equivalent” value of Z measured at Ka band, i.e., the corresponding Z at longer radar wavelength for which Rayleigh scattering takes place. This is achieved via polarimetric retrieval of the mean volume diameter Dm and incorporating the relationship between the dual wavelength ratio DWRS/Ka and Dm. Those techniques allow for retrievals from single millimeter-wavelength radar measurements and do not necessarily require the DWR measurements, if the DWR-Dm relation and Rayleigh assumption for Ka-band KDP are valid. Comparison between the quasi-vertical profile product obtained from KASPR and the columnar vertical profile product generated from the nearby WSR-88D S-band radar measurements demonstrates that the DWRS/Ka can be estimated from the two close radars without the need for collocated radar beams and synchronized antenna scanning and can be used for determining the “Rayleigh-equivalent” value of Z. The performance of the suggested techniques is evaluated for seven winter storms using surface disdrometer and snow accumulation measurements.

Efficacy and Safety of Non-Ablative Dual Wavelength Diode Laser Therapy for Genitourinary Syndrome of Menopause: A Single-Center Prospective Study.

This study evaluates the efficacy and safety of non-ablative diode laser therapy for genitourinary syndrome of menopause (GSM) in post-menopausal women unable to use hormonal therapies. A pilot prospective study was conducted from September 2023 to April 2024, involving 22 post-menopausal women aged 45-73years. Participants underwent three sessions of diode laser treatment with the Leonardo® dual-wavelength Diode laser. Assessments were made at baseline, 3months, and 6months post-treatment. Main outcome measures included Visual Analog Scale (VAS) scores for GSM symptoms, Vaginal Health Index Score (VHIS), and sexual function evaluated using the Female Sexual Function Index (FSFI-6), Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12), and Sexual Quality of Life-Female (SQOL-F) questionnaire. Significant improvements were observed in VHIS, increasing from 12 to 19.27 at 6months (p<0.001). GSM symptoms improved significantly: vaginal dryness scores decreased from 7.72±2.37 to 3.72±2.53, burning sensation scores dropped from 6.00±3.22 to 1.90±1.81, and dyspareunia scores reduced from 8.09±2.11 to 3.90±2.58 (all p<0.016). Sexual function improved, indicated by FSFI-6 scores increasing from 12.27±7.29 to 19.30±6.24 (p<0.016) and SQOL-F scores rising from 63.18±22.93 to 71.45±23.31. No adverse events were reported. Non-ablative diode laser therapy is effective and safe for managing GSM symptoms in post-menopausal women, offering significant symptom relief and enhancing sexual health without serious side effects. Further research with a larger cohort and extended follow-up is needed to confirm these findings. Clinical Trials ID NCT06503003.

Mechanism analysis of dual wavelength laser welding AlN-PC joint based on microtexture treatment

High-strength interfacial bonding between ceramics and transparent polymers is hardly to be achieved, especially in the field of optical packaging of biochips. This paper proposes a novel laser welding method that enhances the joint strength between aluminum nitride (AlN) ceramic and polycarbonate (PC) by laser surface microtexturing. The study investigates the influence of welding methods and microtextures on welding effectiveness, elucidating the bonding mechanisms of the joints. The obtained results showed that dual wavelength laser welding effectively achieves the connection between AlN ceramic and PC. Laser microtexturing increases surface roughness and contact area, leading to stronger mechanical interlocking and overall joint strength. The highest shear strength reached up to 14.66 MPa with longitudinal grooves microtexture. The laser microtexturing improves the hydrophilicity of the AlN surface, facilitating more effective bonding between the materials. The bonding mechanisms at the joint interface include both mechanical interlocking and chemical bonding. Microtexturing improves the stress distribution at the joint interface. The formation of C-O-Al chemical bonds at the interface effectively enhances the joint strength. Longitudinal grooves microtexture exhibit a higher substrate fracture rate due to stress concentration and capillary pores. In contrast, staggered square holes microtexture provide superior mechanical performance through uniform stress distribution and robust mechanical interlocking.

Holographic Multi-Notch Filters Recorded with Simultaneous Double-Exposure Contact Mirror-Based Method

This study presents a novel simultaneous double-exposure contact mirror-based method for fabricating holographic multi-notch filters with dual operational central wavelengths. The proposed method leverages coupled wave theory, the geometric relationships of K-vectors, and a reflection-type recording setup, incorporating additional reflecting mirrors to guide the recording beams. To validate the approach, a holographic notch filter was fabricated using photopolymer recording materials, resulting in operational wavelengths of 531.13 nm and 633.01 nm. The measured diffraction efficiencies at these wavelengths were ηs = 52.35% and ηp = 52.45% for 531.13 nm, and ηs = 67.30% and ηp = 67.40% for 633.01 nm. The component’s performance was analyzed using s- and p-polarized spectral transmission intensities at various reconstruction angles, revealing polarization-independent characteristics under normal incidence and polarization-dependent behavior under oblique incidence. The study also explored the relationships between recording parameters, such as incident angle, wavelength, emulsion expansion, and dispersion. The findings demonstrate that the first operational central wavelength is primarily influenced by the recording wavelength, while the second is primarily determined by the incident angle, covering a range from visible light to near-infrared. This method offers significant potential for cost-effective, mass-produced filters in optoelectronic applications.

Dual–Wavelength Mode–Locked Erbium Fiber Laser Utilizing Ge–PCF Saturable Absorber

Dual–Wavelength Mode–Locked Erbium Fiber Laser Utilizing Ge–PCF Saturable Absorber

Analysis of binary mixture of oxytetracycline and bromohexine in their combined veterinary formulation by four simple spectrophotometric methods with greenness assessment

Tetracyclines family is considered as the first-line antibiotic drugs for food animals. Formulating bromhexine (BR) with oxytetracycline (OTC) improved the antibacterial activity of OTC, besides it is considered as a mucolytic agent. Four precise, rapid, and simple spectrophotometric methods were successfully developed for resolution of the overlapped spectra of OTC and BR in their pure form and in their pharmaceutical formulation. The proposed methods are absorption correction (AC), dual wavelength (DW), induced dual wavelength (IDW), and spectrum subtraction (SS) spectrophotometric methods. The developed methods were used for the determination of OTC and BR in the ranges of 2–50 µg/mL and 1–30 µg/mL, respectively for all methods. For (AC) and (SS) methods, OTC and BR were determined at 380 nm and 245.6 nm, respectively after spectral resolution steps. While for (DW) method, the absorbance difference between λ (271.8 –287.6 nm) and λ (245.6 –283.2 nm) were used for the determination of OTC and BR, in order. For IDW, it depended on using the absorbance difference between 271.8 nm and 245.6 nm as well as the equality factor (F) calculated for each drug at the selected wavelengths. In all methods, HCl was used as a solvent and they are validated according to ICH guidelines. Several green metric tools have been developed to evaluate the greenness of the analytical methods like National Environmental Methods Index (NEMI), Modified NEMI, Analytical Eco-scale, Green Analytical Procedure Index (GAPI) and Analytical GREEnness calculator (AGREE), and all ensured the low impact of the suggested approaches on health and environment. The proposed methods are highly selective, robust and precise. Additionally they are time and money effective and can be used in any analytical laboratory.

A Single-Center, Open-Label, Prospective Study of a 589/1319 nm Dual Wavelength Laser for the Treatment of Facial Hyperpigmentation.

Facial hyperpigmentation, characterized by the excessive production of melanin in the skin, is a prevalent dermatological concern affecting individuals of various ethnic backgrounds. To evaluate the safety and efficacy of a multi-wavelength 589/1319 nm dual-pulse duration laser device for the treatment of hyperpigmentation Patients/Methods: A total of 17 healthy women (mean [SD] age of 43.4 [11.6] with skin phototype II-IV) were enrolled in this prospective, single-center study. Eligible participants received up to 3 treatments spaced 3 to 5 weeks apart with 2 follow-up visits at 4 and 12 weeks after the final treatment. Assessments included investigator ratings of skin quality, global aesthetic improvement, and hyperpigmentation. Safety and tolerability were monitored throughout the study. Significant improvements in hyperpigmentation and skin quality were observed at the 2 follow-up visits from baseline in most patients per investigator assessments. Patient satisfaction was high, and treatments were safe with transient self-resolving side effects such as erythema. Laser treatments using a dual-wavelength 589/1319nm device significantly improve facial hyperpigmentation in patients of various skin types. J Drugs Dermatol. 2024;23(11):943-947. doi:10.36849/JDD.8196.

Evaluation of Ovarian Reserve and Recurrence Rate After DWLS Diode Laser Ovarian Endometrioma Vaporization (OMAlaser): A Prospective, Single-Arm, Multicenter, Clinical Trial

Study ObjectiveTo evaluate the effectiveness of the Dual Wavelength Laser System (DWLS) diode laser on the treatment of ovarian endometrioma (OMA), with ablation and vaporization of the cystic capsule without performing the stripping technique, in terms of ovarian reserve and recurrence rate. DesignProspective, single-arm, multicenter, clinical trial. SettingMulticenter University Hospital. PatientsSeventy patients with symptomatic OMA. InterventionsPatients underwent surgery for primary unilateral or bilateral symptomatic OMA treated with DWLS diode laser vaporization. Following surgical intervention, patients were enrolled in a 12 months surveillance protocol featuring regular clinical assessments aimed at detecting ovarian reserve, pregnancy rate and any recurrence of the cyst and/or symptomatic relapse. Measurements and Main ResultsAntimullerian hormone (AMH) levels at the 3-month follow-up exhibited a significant difference from the baseline (p = .034), demonstrating a return to nearly presurgical values in the subsequent months. Antral follicle count (AFC) of the operated ovary showed a significant increase after treatment at the 6-month and 12-month follow-up (p = 0.005 and p = 0.002, respectively). Pregnancies were documented in 48.3% (14/29) of infertile patients who underwent treatment. OMA recurrence was observed in 4 patients (5.7%) at 12 months. No patient exhibited a significant relapse of the analyzed symptoms compared to baseline values. ConclusionThe findings of this study propose that DWLS diode laser presents a good option for treating OMA, demonstrating minimal impact on the surrounding healthy ovarian tissue, favorable pregnancy rate, coupled with low recurrence rates.

Intelligent spectrophotometric resolution platforms for the challenging spectra of ipratropium and fenoterol in their combination inhaler with ecological friendliness assessment.

Asthma and chronic obstructive pulmonary disease (COPD) are the most common diagnoses for adults and children with respiratory tract inflammation. Recently, a novel fixed dose combination consisting of Ipratropium and Fenoterol has been released for the management and control of the symptoms of such disorders. The current research has newly developed andoptimizedthree smart, accurate,simple, cost-effective, and eco-friendly spectrophotometric methods that enabled the simultaneous determination of the drugs under study in their combined inhaler dosage form, without the need for any previous separation steps, using water as a green solvent. The strategy employed was based oncalculating oneor two factors as a numerical spectrum or constant, whichprovided thecomplete removal of any component in the mixture that might overlap and the mathematical filtration of the targeted analyte. The methods developed could be classified into twotypesof spectrophotometric windows. Window I; involved absorption spectrum in their original zero-order forms (°D), which included recently designed methods named induced concentration subtraction (ICS) and induced dual wavelength (IDW). While window III focused on the ratio spectrum as theinduced amplitude modulation (IAM) method. The extremely low absorptivity and lack of distinct absorption maximum in the zero-order absorption spectrum of Ipratropium were two intrinsic challenges that were better overcome by the proposed spectrophotometric methods than by the conventionally used ones. According to ICH guidelines, the proposed methods were validated using unified regression over range 2.0-40.0 µg/mL in the ICS method, while the linearity ranges for the IDW and IAM methods were 5.0-40.0 µg/mL of Ipratropium and 2.0-40.0 µg/mL of Fenoterol. Moreover, the three proposed methods were effectively used to assay the co-formulated marketed inhaler and further expanded to confirm the delivered dose uniformityin compliance with the USP guidelines. Finally, the established methods were evaluated for their greenness and blueness, in comparison to the official and reported analysis methods, using advanced cutting edge software metrics. Furthermore, the suggested techniques adhered well to the white analytical chemistry postulates that were recently published.

Temperature-controlled synthesis of novel boron nanofibers by laser ablation technique

The synthesis of boron nanofibers (BNFs) at different temperatures using the double-pulsed laser ablation (DPLA) technique were reported. Q-switched Nd: YAG laser with 532 and 1064 nm dual beam wavelengths of laser used to ablate a solid boron target. A vapor–solid process at a furnace temperature and pressure supported boron 'nanofibers' growth with the active metal catalysts of 1 % Ni and 1 % Co in a quartz tube furnace in flowing argon (Ar) gas. The crystalline phase purity of the synthesized BNFs at 950, 1050, and 1150 °C were determined by X-ray diffraction (XRD), and the results from XRD confirm that each BNF is preferentially grown in the c-axis (100) direction of alpha boron (α-B). Electron microscopy revealed that each BNF exhibit a length of 1–5 μm and a diameter width of 5–100 nm, while the elemental chemical compositional nature of the BNFs is identified from energy dispersive X–ray spectroscopy (EDX). Image analysis shows the average diameter of each BNF synthesized to be 23.10, 19.13, and 16.09 nm. The lattice distance of each BNF is found to be 0.40, 0.39, and 0.38 nm, respectively. Fingerprint Raman spectroscopy revealed the fundamental vibrational modes of BNFs at Eg and A1g.

A novel dual-site fluorescent probe for the one-step detection of Cys and SO2 in living cells

BackgroundCysteine (Cys) is the major intracellular thiol and plays a key role in human pathology. Furthermore, endogenous sulfur dioxide (SO2) is produced in mammals. Abnormal levels of SO2 are commonly associated with a variety of respiratory, cardiovascular, and neurological diseases. Therefore, given their important role in life activities, it is significant to construct a fluorescent probe that can detection between Cys and SO2. ResultsWe have designed and synthesized a two-site fluorescent probe CUM with coumarin derivative and benzaldehyde molecules, which can detect and differentiate between Cys and SO2 through dual excitation wavelengths. Its carbon-carbon double bond reacts with Cys and undergoes a nucleophilic reaction, emitting green fluorescence at 520 nm, while SO32− reacts with benzaldehyde molecules in the probe CUM and undergoes a blue fluorescence at 460 nm. SO32− reacts with the benzaldehyde molecule of probe CUM and fluoresces blue at 460 nm. Thus, the probe CUM with two reaction sites can distinguish between Cys and SO2 and shows good selectivity and fast reaction speed. In addition, we successfully utilized probe CUM to image Cys and SO2 in human breast cancer cells (MDA-MB-231). SignificanceThis work provides an effective method for the molecular design of coumarin-based fluorescent probes. Probe CUM as a promising and reliable tool for the meticulous discrimination and quantification of Cys and SO2 in diverse biological matrices, thereby opening up new avenues for various biological systems.

Metasurface Enabled Multi‐Target and Multi‐Wavelength Diffraction Neural Networks

AbstractBenefiting from low power consumption and high processing speed, there is a growing interest in diffraction neural networks (DNNs), which are typically showcased with 3D printing devices, leading to large volumes, high costs, and low levels of integration. Metasurfaces can desirably manipulate wavefronts of electromagnetic waves, providing a compact platform for mimicking DNNs with novel functions. Although multi‐wavelength and multi‐target recognition provides a richer and more detailed understanding of complex environments, existing architectures are primarily trained to classify a single target at a specific wavelength. A metasurface approach is proposed to design multiplexed DNNs that can classify multiple targets and spatial sequences across various wavelengths in multiple channels. To realize multi‐task processing, the dielectric metasurface is designed based on phase and wavelength multiplexing, which can integrate multi‐target DNNs with different tasks such as operating at distinct wavelengths and classifying diverse targets. The efficacy of this method is exemplified through the numerical simulation and experimental demonstration of recognizing a single target with two wavelengths, two targets at a single wavelength, and two targets at dual wavelengths. This compact metasurface approach enables the design of multi‐target and multi‐wavelength DNNs, opening a new window to develop massively parallel processing and versatile artificial intelligence systems.

Design and wavelength selection of compact dual-wavelength Yb:YAG lasers with a Z-shaped cavity

The compact dual-wavelength Yb:YAG lasers were designed and developed by employing a Z-shaped cavity. The overall cavity length is about 32 cm, which can be packaged in a device size of 15 × 10 cm2. The oscillating beam radius in the laser crystal varied by the cavity length, and stable dual wavelength laser was achieved. The 1050 nm output of 1.44W was obtained at the highest pump power is 10 W when the oscillating beam radius was 125 μm. The balance dual-wavelength output of 0.93W was achieved with the optical to optical conversion efficiency of 9.3%. The output wavelengths of the Yb:YAG laser depended on the oscillating beam radius, which was consistent with the experimental results. Our findings indicated that while stringent mode matching was ideal, there was a degree of flexibility that can be tolerated without significantly compromising the laser's performance, which can be beneficial for the dual-wavelength oscillation in applications.

Dual-window polarization filtering characteristics of rectangular photonic crystal fibers

This paper presents a photonic crystal fiber (PCF) polarization filter with a square array arrangement of gold film fillings, allowing for filtering at dual wavelengths. The paper analyzes the dispersion characteristics and loss properties of this structure and optimizes the structural parameters through adjustments to achieve the best performance. At 1310 nm, the confinement losses of x and y polarization fundamental modes are 903.54 dB/cm and 30.51 dB/cm, respectively; at 1640 nm, the confinement losses of y and x polarization fundamental modes are 479.02 dB/cm and 88.72 dB/cm, respectively. The corresponding filtering bandwidths are 390 and 350 nm, while the full width half maximum (FWHM) is 59.56 nm, indicating excellent selectivity and resolution of the filter. The performance metrics, such as confinement loss, extinction ratios, and bandwidth, are compared in the paper with those reported for other filters. Additionally, the study also analyzed the filter’s performance under varying manufacturing tolerances of gold film thickness and air hole diameter by 5%, revealing that the filter’s performance remains stable and feasible even in the presence of errors.

Impact of dual wavelength laser therapies in the treatment of hypertrophic scars and keloids: a systematic review

Impact of dual wavelength laser therapies in the treatment of hypertrophic scars and keloids: a systematic review

Orthogonally polarized dual-wavelength Pr:LiYF4 lasers in 1.3 μm region

We report a continuous-wave (CW) orthogonally polarized dual-wavelength Pr:LiYF4 laser in 1.3 μm region pumped by a Yb-doped fiber laser. The gain and loss of the wavelengths in the orthogonally polarized directions were balanced by an inclined etalon inserted into the cavity. At an absorbed pump power of 9.2 W, a dual-wavelength laser operating at 1310 nm in π-polarization and 1326 nm in σ-polarization with 2.26 W of total output power was achieved. Moreover, by continuing to adjust the tilt angle of the etalon, the three other pairs of dual-wavelengths (1289 and 1306 nm, 1289 and 1306 nm, and 1306 and 1310 nm) were also obtained. The output power ratio of each pair of dual wavelengths was nearly 1:1. To the best of our knowledge, this is the first work realizing the Pr:LiYF4 laser operating in 1.3 μm region.