High-intensity Laser Research Articles

Probing ALPs at the LUXE experiment

The proposed LUXE experiment (LASER Und XFEL Experiment) at DESY, Hamburg, aims to probe QED in its non-perturbative regime. In order to do this, LUXE will study the interactions between 16.5 GeV electrons from the European XFEL and high-intensity laser pulses. This experiment also provides a unique opportunity to probe physics beyond the Standard Model: exploiting the large photon flux generated at LUXE, it is possible to design a dedicated detector to probe axion-like-particles up to a mass of 350 MeV and with photon coupling of 3 \cdot 10^{-6}3⋅10−6 GeV^{-1}−1. This reach is comparable to the projected sensitivity of experiments like FASER2 at the HL-LHC and NA62 operating in dump mode.

The Addition of Exercise to High-Intensity Laser Therapy Improves Treatment Effectiveness on Pain and Muscle Strength in Patients with Subacromial Pain Syndrome: A Randomized Trial

Abstract Objective To assess the efficacy of adding exercise to high-intensity laser therapy (HILT) in improving treatment effectiveness for clinical outcomes in patients with subacromial pain syndrome. Methods Thirty patients with subacromial pain syndrome were randomly assigned to the HILT-only group (n=15) or HILT&Exercise group (n=15). The primary outcome was shoulder function and disability. Secondary outcomes were pain, range of motion, proprioception (joint position sense), and muscle strength. Results Shoulder function and disability, pain, range of motion, joint position sense, and some muscle strength improved in both groups (p<0.05). There was no significant time-group interaction for the Constant-Murley Score, Shoulder Pain and Disability Index, rest pain, range of motion, and joint position sense (p>0.05). Time-group showed significant effects for activity pain and strength in favor of the HILT&Exercise group. Middle trapezius, lower trapezius, and supraspinatus strength increased after HILT plus exercise (p<0.05), activity pain, upper trapezius, serratus anterior, and subscapularis strength improved more compared to HILT (p<0.05). Conclusions We found no clinically important differences between HILT and HILT-plus exercise in shoulder function and disability, rest pain, mobility, and proprioception, in patients with subacromial pain syndrome. The addition of exercise to HILT was superior to HILT for improving activity pain and muscle strength.

A close look at temperature profiles during laser powder bed fusion using operando X-ray diffraction and finite element simulations

In laser powder bed fusion (LPBF), complex components are manufactured layer-by-layer via scanning the cross-sections of a 3D CAD model using a high intensity laser. Throughout this process, the material is exposed to temperature profiles that significantly differ from conventional manufacturing methods, and result in development of a unique and inhomogeneous microstructure and high levels of residual stresses in additively fabricated parts. The large temperature gradients and rapid cooling rates around the moving laser spot, and the overall heterogeneity of the temperature field need to be better understood in order to optimize the process parameters for increased production quality. In this study, operando X-ray diffraction (XRD) was employed to measure and compare temperature histories on the laser path under various processing conditions for Hastelloy X. Finite element thermal simulations were validated based on the acquired XRD data and then used as a supplementary tool to discuss the cooling behaviour and thermal heterogeneities across the geometry. The increase in the deposited energy density was qualitatively linked with higher temperature levels and slower cooling rates during LPBF. The melt-pool lengths showed strong sensitivity to the laser power and little variation with the scanning speed. Furthermore, even for a single set of parameters, large variations in the temperature field within the build were observed such that the cross-section edges located at higher build layers were exposed to markedly higher temperature levels.

Efficacy of Low-level Laser Versus High-intensity Laser Therapy in the Management of Adhesive Capsulitis: A Randomized Clinical Trial.

Low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) are effective in alleviating pain and improving functionality in patients with adhesive capsulitis (AC); however, no study has compared the efficacy of these two laser treatments. To compare the effectiveness of LLLT and HILT in improving the shoulder joint range of motion and functional status and in reducing pain level in patients with AC. Prospective, randomized, parallel group, patient- and assessor-blinded. A total of 45 patients (aged: 18-65 years) with complaint of shoulder pain were evaluated for inclusion criteria, which included being aged 18-65 years and a diagnosis of AC based on physical examinations. Using computer-generated random numbers, eligible patients were randomized into two groups: HILT + stretching exercise and LLLT + stretching exercise groups. Both HILT and LLLT were performed three times/week for 3 weeks. Functional status and pain of the patients were evaluated with Shoulder Pain and Disability Index (SPADI) and Visual Analog Scale (VAS), while shoulder joint range of motion was measured with goniometry. All assessments were done before and 3 weeks after treatment. A total of 40 patients (20 in each group) completed the study. At baseline, there was no statistically significant difference in the demographic and clinical characteristics between both groups. Both the LLLT and HILT groups showed significant improvement in the VAS and SPADI scores 3 weeks after treatment; however, the improvement was significantly higher in the HILT group than the LLLT group. There was no significant improvement in goniometric scores in both groups compared with baseline. No injury or other musculoskeletal complications were recorded during or after the treatments. HILT + stretching exercise treatment was more effective than LLLT + stretching exercise for improving functional parameters and pain in patients with AC. ClinicalTrials.gov Identifier: NCT05469672. None.

High-intensity laser guiding in a plasma: amplitude modulation effects

High-intensity laser guiding in a plasma: amplitude modulation effects

Four-dimensional dynamics of multirotational transition stimulated rotational Raman scattering in air

Stimulated rotational Raman scattering in air is a powerful parasitic process that degrades high intensity laser beams and pulses propagated over significant distances. Conversely, it is used beneficially in the context of Raman lasers. Through this inelastic scattering process, laser photons are converted to higher (anti-Stokes) or lower (Stokes) energies, according to rotational mode transitions in nitrogen and oxygen diatomic molecules. The full wave-mixing problem involves numerous frequencies, and it is consistently assumed that only one rotational mode contributes to the conversion process. We instead present a dynamic 4D multirotational model that is implemented in a parallelized manner within the Virtual Beamline++ optical modeling package allowing high-resolution 4D studies. We highlight the effect that spontaneous emission plays in large and small beam-width setups, even in the highly saturating regime. The weaker transition modes play a large role in the persistent dynamics and can lead to complex spatiotemporal coupling through nonlinear competition of the modes. We highlight how and why these weaker modes persist, how the size and shape of speckle patterns depends highly on the initial beam profile, and how weaker modes can transiently become stronger as a result of such competition.

Ion acceleration from a multispecies nanostructured target using a high-intensity laser: a simulation study

The use of nanostructured targets can enhance the energy and quality of accelerated electron and ion beams compared to conventional flat foil targets. Ion acceleration from plastic foil targets having sub-micron thickness embedded with rods of nanometre length using ultra-short intense laser pulses of intensity W cm−2 is investigated using particle-in-cell simulations. The laser and target parameters are tuned to achieve better performance with nanostructured targets compared to flat foils. Several novel features of the ion acceleration process are revealed in this study. A hybrid radiation pressure acceleration-target normal sheath acceleration mechanism using a linearly polarised (LP) laser is found to play a key role in accelerating protons upto ∼300 MeV of energy. The effects of multiple ion species on the acceleration of protons has been studied, and a narrow peak in the proton energy spectrum around ∼100 MeV is observed, which is attributed to the presence of heavier ions in the target.

Role of topological charges in the nonlinear optical response from Weyl semimetals

The successful realization of the topological Weyl semimetals has revolutionized contemporary physics. In recent years, multi-Weyl semimetals, a class of topological Weyl semimetals, has attracted broad interest in condensed-matter physics. Multi-Weyl semimetals are emerging topological semimetals with nonlinear anisotropic energy dispersion, which is characterized by higher topological charges. In this study, we investigate how the topological charge affects the nonlinear optical response from multi-Weyl semimetals. It has been observed that the laser-driven electronic current is characteristic of the topological charge, and the laser polarization's direction influences the current's direction and amplitude. In addition, the anomalous current, perpendicular to the laser's polarization, carries a distinct signature of the topological charges and encodes the information about the parity and amplitude of the nontrivial Berry curvature. We show that the anomalous current associated with the anomalous Hall effect remains no longer proportional to the topological charge at higher laser intensity -- a significant deviation from the linear response theory. High-harmonic spectroscopy is employed to capture the distinct and interesting features of the currents in multi-Weyl semimetals where the topological charge drastically impacts the harmonics' yield and energy cutoff.

Light in Orthodontics: Applications of High-Intensity Lasers, Photobiomodulation, and Antimicrobial Photodymanic Therapies in Daily Practice

Orthodontics is constantly seeking innovation towards mechanical efficiency and better oral-related quality of life during treatment. This narrative review aims to discuss novel scientific reports about light therapies and how they can optimize different stages of orthodontic intervention: before, during, and after treatment. Recurrent conditions that can be treated with laser devices are the removal of carious tissue, dentin hypersensitivity, and temporomandibular disorders. Evidence reveals that laser procedures accelerate health recovery, enabling individuals to initiate orthodontic treatment. Along orthodontic procedure, photobiomodulation therapy, is indicated for analgesia after appliance activations, repair of traumatic ulcers, and acceleration of tooth movement. Moreover, antimicrobial photodynamic therapy is well-indicated for effective decontamination of oral infections such as herpetic lesions and peri-implantitis. Finally, high-intensity lasers are good allies in removing brackets and reconditioning red esthetics. There are many benefits to the use of light sources in the orthodontic routine: simplicity of technique, ease of handling devices, minimal invasiveness, and patient comfort during procedures. It is essential that professionals develop a critical overview of technological advances, offering safe and evidence-based therapies. Recent advances indicate that laser therapies improve patient experiences during orthodontic treatment and minimize the side effects of clinical interventions.

MP-CITDSE: A set of ab-initio programs for the simulation of hydrogenic and helium-like atom-laser interactions

MP-CITDSE is a package of programs which solves the time-dependent Schrödinger equation for hydrogenic and helium-like atomic systems interacting with an ultra-short laser pulse (of attosecond or femtosecond duration). The output of the computations – with some minimal processing – may be used to calculate excited populations, single and double ionisation yields, kinetic, angular and radial electron distributions, and harmonic yields. For the Helium atom, a full account of the inter-electronic correlation effects is included via a configuration interaction approach; for the time propagation of the wavefunction a spectral basis expansion on the eigenstates of the field-free Hamiltonian is used; for this reason post-processing of the expansion coefficients just after the pulse lead to simple formulas for quantities of experimental interest. Program summaryProgram Title: MP-CITDSECPC Library link to program files:https://doi.org/10.17632/gv4zxmfdx3.1Developer's repository link:https://github.com/aforembs/MP-CITDSELicensing provisions: GPLv3Programming language: C++Nature of problem: The ultra-fast high-intensity laser pulses of modern experimental sources require an ab-initio theoretical treatment, as the characteristics of such pulses are generally incompatible with the established Lowest-order Perturbation Theory (LOPT) approximation. Such a treatment can be quite cumbersome to not only implement, but also describe in a clear, intuitive manner. Its inherent complexity ensures that even in its simplest form, an ab-initio TDSE solver can easily consist of several thousand lines of code. As with any project of such scope a significant amount of effort is required to keep the code up to date, running on several platforms, compilers and operating systems. As such, while the numerical problem tackled by MP-CITDSE is that of the simulation of hydrogenic and helium-like atom-laser interactions on a single node computer/workstation; its main challenges are longevity and expandability. By doing away with unnecessary abstractions within the code, using a modern standard of a widely used and performant language (C++ 17) and hosting the source code on a publicly available GitHub repository we hope that the programs provided herein prove themselves useful to many current and future AMO Physicists.Solution method: The atomic systems are considered confined in a spherical box of finite size. In the one-electron case (hydrogen) the eigenstates are calculated in a spherical coordinate system by the direct diagonalisation of the field-free Hamiltonian matrix representation on a B-splines piecewise polynomial basis expansion of the radial part of the eigenfunctions; for the two-electron case (helium) the numerically calculated one-electron eigenstates are angularly coupled to form a zero-order (uncorrelated) two-electron numerical basis; then the latter basis is further coupled via a configuration-interaction approach to eventually calculate the helium's two-electron eigenstates.Following these steps, for both systems (hydrogen and helium) the computation proceeds by expanding the time-dependent wavefunction on the corresponding field-free eigenstate basis; thus, we end up to a system of first-order ordinary differential equations (ODEs) in time for the expansion (time-dependent) coefficients; the dynamical parameters for the ODEs time propagation, namely the eigenenergies and dipole matrix elements are calculated only once prior to the ODEs propagation [2]. The structure of the propagating matrix is block tridiagonal.Additional comments including restrictions and unusual features: This paper serves as the definitive reference for the MP-CITDSE code. In this version we solve the ODEs using a Runge-Kutta-Felnberg (RKF) algorithm. Also we have restricted the code to treat hydrogen and helium but with very little effort (non-relativistic) hydrogenic and helium-like atomic systems can also be simulated. The programs are supplied with two methods of compilation, via make and cmake to ensure greater portability.

THE MULTIDISCIPLINARITY IMPORTANCE IN REHABILITATION AFTER THE VERRUCOUS CARCINOMA DIAGNOSIS: A CASE REPORT

Verrucous carcinoma of the oral cavity is low-grade and a rare variant of squamous cell carcinoma. This lesion is described as malignant, exophytic, slowly growing, and locally invasive. The following case aims to report how the lesion localization and tissue healing led to a difficult rehabilitation. An 86-year-old, Caucasian female patient was referred for rehabilitation after having performed partial maxillectomy. Before surgery, a unique lesion with an irregular appearance and with papillary projections was observed. Histologically, it has shown epithelial ridges without significant dysplasia and keratin plugs. Her clinical history was collected and confronted with the anatomopathological exam, confirming verrucous carcinoma in the anterior maxillary ridge. A second surgical intervention, using high-intensity laser therapy, was necessary to improve the maxilla into a better prosthetic bed, increasing retentive areas. A healing guide plate was installed in the immediate post-surgery time to support the tissue before implementing the reparatory prosthesis. Verrucous carcinoma of the oral cavity is low-grade and a rare variant of squamous cell carcinoma. This lesion is described as malignant, exophytic, slowly growing, and locally invasive. The following case aims to report how the lesion localization and tissue healing led to a difficult rehabilitation. An 86-year-old, Caucasian female patient was referred for rehabilitation after having performed partial maxillectomy. Before surgery, a unique lesion with an irregular appearance and with papillary projections was observed. Histologically, it has shown epithelial ridges without significant dysplasia and keratin plugs. Her clinical history was collected and confronted with the anatomopathological exam, confirming verrucous carcinoma in the anterior maxillary ridge. A second surgical intervention, using high-intensity laser therapy, was necessary to improve the maxilla into a better prosthetic bed, increasing retentive areas. A healing guide plate was installed in the immediate post-surgery time to support the tissue before implementing the reparatory prosthesis.

Collimation and energy enhancement in laser driven MeV protons

Enhancing the energy and controlling the divergence of proton beam have been crucial tasks since the development of laser-based ion accelerators. In this study, we employ 2D particle-in-cell EPOCH simulation to investigate a method to control the divergence and enhance the energy of MeV proton beam produced from the interaction of high intensity laser with a gold target. The energy and divergence of proton beam for the conventional laser-foil target configuration are compared with our proposed three laser-three target configuration. In the single laser-single target configuration, a high intensity laser irradiates a gold foil target resulting in proton acceleration from the plasma. In contrast, in the three laser-three target configuration, the generated proton beam is allowed to traverse through the configuration of two parallel Al plates irradiated with high intensity lasers. The new configuration provides the proton energy enhancements of 40% and more collimated beam compared to the single laser-foil target setup. This collimation and energy increase are due to the vertical and horizontal components of the electric field generated by the hot electron plasma of Al plates. The proton energy and divergence can also be tuned by varying the plasma electron density of the Al plasma. Also, the control of proton beam collimation is explored by varying target parameters as well, and it is observed that the separation between the Al plates and length of the Al plates plays major role in controlling the divergence of the beam. This study will have a significant impact in the ongoing laser fusion program, fast ignition, and laser ion therapy.

Enhanced target normal sheath acceleration with a grooved hydrocarbon target

The interaction of a high-intensity ultrashort laser pulse with a few micrometers-thick hydrocarbon target is known to accelerate protons/ions to multi-MeV, on the rear side of the target, via the mechanism of target normal sheath acceleration. Micro-structuring the target front is one of the promising approaches to enhance the cutoff energy as well as to reduce the divergence of accelerated protons/ions. In this paper, the interaction of a normally incident intense laser pulse with targets having single micrometer-sized grooves, at their front side, of semi-circular, triangular, and rectangular shapes has been studied by using two-dimensional particle-in-cell simulations. It is observed that as compared to a flat target for targets with a rectangular groove at the front side the focused hot electron beam at the rear side results in an approximately fourfold increase in the cutoff energy of accelerated protons. For triangular and semi-circular groove targets, the cutoff energy remains comparatively lower (higher than the flat target though). The angular divergence of the accelerated protons/ions is also found to be relatively much lower in the case of a rectangular groove.

Effect of non-local transport of hot electrons on the laser-target ablation

The non-local heat transport of hot electrons during high-intensity laser interaction with plasmas can preheat the fuel and limit the heat flow in inertial confinement fusion. It increases the entropy of the fuel and decreases the final compression. In this paper, the non-local electron transport model that is based on the improved Schurtz–Nicolaï–Busquet (SNB) algorithm has been embedded into the radiation hydrodynamic code and is benchmarked with two classical non-local transport cases. Then, we studied a 2ω laser ablating a CH target by using the non-local module. It is found that the non-local effect becomes significant when the laser intensity is above 1×1014W/cm2. The mass ablation rate from the SNB model is increased compared to that of the flux-limited model due to the lower coronal plasma temperature. This non-local model has a better agreement with the experimental results compared to that of the flux-limited model. The non-local transport is strongly dependent on the laser frequency, and the thresholds that the non-local transport should be considered are obtained for lasers of different frequencies. The appropriate flux-limiters that should be employed in the flux-limited model for different lasers are also presented. The results here should have a good reference for the laser-target ablation applications.

Computational Evaluation of the Effect of Build Orientation on Thermal Behavior and in-situ Martensite Decomposition for Laser Powder-Bed Fusion (LPBF) Process

Laser powder bed fusion (LPBF), which is an additive manufacturing method, is a thermo-mechanical process in which instantaneously varying heat flow rates occur by moving a high-intensity laser beam. The high temperatures and cooling rates that occur throughout the process result in microstructures with brittle behavior. The microstructure and mechanical properties may be improved by controlling the cooling rates in the layers via build orientation. Since the process is on a microscale, it requires planning as it does not allow instant intervention. Therefore, numerical analysis can be helpful to determine the effect of different build orientations. In this study, the effect of different build orientations was emphasized. For this purpose, successive layers resulting in narrowing and expanding cross-sectional areas were investigated with a detailed thermal approach. Also, a martensite decomposition case, as a result of changing the build orientation for a geometry, was presented numerically. As a result, it is shown that build orientation has an effect on the heat distribution within the part. Some benefits of expanding the cross-sectional area have been determined. Specifically, it is found that the build orientation may also enable local martensite decomposition, contributing to a lamellar microstructure.

Intrapulse Correlated Dynamics of Self-Phase Modulation and Spontaneous Raman Scattering in Synthetic Diamond Excited and Probed by Positively Chirped Ultrashort Laser Pulses

In synthetic diamond plates, the intrapulse-correlated dynamics of self-phase modulation and spontaneous nonresonant Raman scattering by center-zone optical phonons were for the first time directly investigated for tightly focused (focusing numerical aperture NA = 0.25) positively chirped visible-range high-intensity laser pulses with variable durations (0.3–9.5 ps) and energies transmitted through the sample. The observed self-phase modulation broadening and modulation of the transmitted light and Stokes Raman spectra for the (sub)picosecond pulse durations indicate the considerable Raman–Kerr contribution to the nonlinear polarization. The latter appears through plasma emission of the optical phonons, which emerges on the (sub)picosecond timescale and dominates at ≈1 ps. Later, this phonon contribution is eventually suppressed in the material due to picosecond-scale electron-lattice thermalization and the related thermally enhanced symmetrical decay of optical phonons into lower-frequency acoustic ones.

Comparison of Extracorporeal Shockwave and High-Intensity Laser in Treating Chronic Plantar Fasciitis

Background: Plantar fasciitis (PF), an inflammation of the plantar fascia. This study compared the effects of the extracorporeal shockwave and high-intensity laser in reducing pain and enhancing function in chronic plantar fasciitis patients, who have failed to achieve results by the conservative treatment. Aim: To explore the best non-invasive treatment option for chronic PF within the scope of physical therapy. Method: After registry of trial the data collection was started.A total of45 chronic PF patientswere divided, randomly into three groups. Group 1 received BTL-6000 Shockwave therapy (ESWT) , group 2 received Diowave 60W Class IV hot Laser (HILT) and group 3 (the control group) was not given any electrotherapy treatment. All groups were given some exercises for the home plan. The groups were assessed with the Visual Analogue scale (VAS) and foot functional index (FFI) at baseline, post-treatment, and follow-up of 2 months. Result: The mean age of participants was 39.66±10.05,38.06 ±12.64 and 37.40±13.18 for ESWT, HILT group and control groups respectively. There was significant difference in VAS and FFI score p=<0.001 across the time. Pre-treatment and post-treatment scores were significantly different but post treatment and follow-up scores were not significantly different for both VAS and FFI score (p=1.00). Practical implication: This study will help us to find out chronic Plantar fasciitis treatment within physical therapy and electrotherapy domain. As both these modalities are non-invasive, cost effective and proved as effective treatment for reduction of pain and improvement of pain in chronic plantar fasciitis patients. Conclusion: Extracorporeal shockwave have been promising treatment for chronic plantar fasciitis but High intensity LASER therapy effectiveness was not explored a lot in previous literature. The study concluded that both ESWT and HILT are effective in reducing pain and improving function on VAS and FFI, though the ESWT group was found better than both groups in FFI score and VAS across time on the basis of the mean differences across time. Keywords: Exercise, Extra-corporeal shockwave therapy, heel pain, High-intensity Laser therapy, Plantar fasciitis

Comparative analysis of different physical therapy programs in the treatment of people with knee osteoarthritis

Introduction: Knee osteoarthritis (OA) develops gradually and causes pain, a decrease in range of motion, muscle mass, and strength and leads to a decrease in physical activity and a poor quality of life for the patient. The aim of this study was to investigate the effects of different physiotherapy programs on pain intensity, range of motion, and quality of life in people with knee OA. Methods: The study was designed as a prospective, experimental, and randomized trial. Sixty subjects of both sexes and all ages with OA of the knee were enrolled in the study. In the studied Group I (n = 30), in addition to the standard protocol, high induction electromagnetic stimulation was applied using a Salus Talent device with a strength of 3 T and a frequency of up to 50 Hz for 10 min. In the test Group II (n = 30), in addition to the standard protocol, high-intensity laser therapy (HILT) with a power of 5 J was applied with the help of the Ilux Yag 1064 device for 7 min. The therapy protocol for both test groups lasted 8 weeks, with subjects treated once a week. Results: Analysis of the mean scores on the VAS scale shows that in both groups, the lowest mean scores were recorded in the III measurement (4.35) and the highest in the I measurement (7.96). In all three measurements, there was a difference in the extent of mobility of internal rotation in the form of a higher average range of motion in the test group II, in which HILT was applied. Analysis of the mean scores on the knee injury and osteoarthritis outcome score quality of life scale showed that in both groups, the lowest mean scores were recorded at the first measurement (14.84), with the mean score increasing at the second (32.95) and third measurements (41.08). Conclusion: Both methods showed significant results in reducing pain intensity, improving knee mobility, activities of daily living, and quality of life in people with knee OA. The obtained data do not give preference to any method but indicate them as adequate physiotherapy protocols to improve the function and quality of life of people with knee OA.

Challenge of search for cosmological dark components with high-intensity lasers and beyond

Challenge of search for cosmological dark components with high-intensity lasers and beyond

Study on subsurface microcrack damage depth of diamond wire as-sawn sapphire crystal wafers

Sapphire crystals are widely used as window materials for infrared emitting devices, high intensity lasers, optical elements and microelectronic substrates due to the excellent material properties. The subsurface microcrack damage produced by diamond wire saw when cutting sapphire crystal is an important indicator of the cutting quality. In this paper, diamond wire sawing experiments were conducted within the industrial production processing parameters to investigate the as-sawn sapphire crystal wafers subsurface microcrack damage depth (SSD), and a numerical calculation model was established to predict the SSD based on the analysis of the scratching stress field of single abrasive. The effects of the saw wire speed and specimen feed speed, saw wire parameters on SSD were predicted. The results show that, within the parameters studied in this paper, the material was removed in brittle mode, increasing the saw wire speed (from 1000 m/min to 1600 m/min) and reducing the specimen feed speed (from 0.5 mm/min to 0.05 mm/min) can reduce the sapphire as-sawn wafers SSD, reduce the size of brittle tear-shape edge breakage, the number and size of brittle pits on the as-sawn wafer surface are reduced and the surface morphology consistency is improved. Increasing the abrasive density and reducing the abrasive size can reduce the SSD. The study results provide a reference for the reasonable matching of sawing process parameters and saw wire parameters in industry.