The impact of strained layers on current and emerging semiconductor laser systems

2019 ◽  
Vol 125 (8) ◽  
pp. 082538 ◽  
Author(s):  
Stephen J. Sweeney ◽  
Timothy D. Eales ◽  
Alfred R. Adams
Keyword(s):  
Semiconductor Laser ◽  
Strained Layers ◽  
Laser Systems ◽  
The Impact

The impact of photodarkening on mode instabilities in high-power fiber laser systems

2014 ◽  
Author(s):  
Cesar Jauregui ◽  
Hans-Jürgen Otto ◽  
Norbert Modsching ◽  
Oliver de Vries ◽  
Jens Limpert ◽  
...  
Keyword(s):  
Fiber Laser ◽  
High Power ◽  
Laser Systems ◽  
The Impact

scholarly journals Improved Process Efficiency in Laser-Based Powder Bed Fusion of Nanoparticle Coated Maraging Tool Steel Powder

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3465
Author(s):  
Oliver Pannitz ◽  
Felix Großwendt ◽  
Arne Lüddecke ◽  
Arno Kwade ◽  
Arne Röttger ◽  
...  
Keyword(s):  
Tool Steel ◽  
Steel Powder ◽  
Process Efficiency ◽  
Powder Materials ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Laser Systems ◽  
Additional Improvement ◽  
Few Layer Graphene ◽  
The Impact

Research and development in the field of metal-based additive manufacturing are advancing steadily every year. In order to increase the efficiency of powder bed fusion of metals using a laser beam system (PBF LB/M), machine manufacturers have implemented extensive optimizations with regard to the laser systems and build volumes. However, the optimization of metallic powder materials using nanoparticle additives enables an additional improvement of the laser–material interaction. In this work, tool steel 1.2709 powder was coated with silicon carbide (SiC), few-layer graphene (FLG), and iron oxide black (IOB) on a nanometer scale. Subsequently, the feedstock material and the modified powder materials were analyzed concerning the reflectance of the laser radiation and processed by PBF-LB/M in a systematic and consistent procedure to evaluate the impact of the nano-additivation on the process efficiency and mechanical properties. As a result, an increased build rate is achieved, exhibiting a relative density of 99.9% for FLG/1.2709 due to a decreased reflectance of this modified powder material. Furthermore, FLG/1.2709 provides hardness values after precipitation hardening with only aging comparable to the original 1.2709 material and is higher than the SiC- and IOB-coated material. Additionally, the IOB coating tends to promote oxide-formation and lack-of-fusion defects.

Research progresses of optical chaos in semiconductor laser systems

2021 ◽  
Vol 0 (0) ◽  
pp. 1-12
Author(s):  
KUANG Shang-qi ◽  
◽  
◽  
GUO Xiang-shuai ◽  
FENG Yu-ling ◽  
...  
Keyword(s):  
Semiconductor Laser ◽  
Optical Chaos ◽  
Laser Systems

Surgery of benign and tumor-like laryngeal formations using 445 nm semiconductor laser

2021 ◽  
Vol 20 (6) ◽  
pp. 102-108
Author(s):  
A. A. Krivopalov ◽  
◽  
P. A. Shamkina ◽  
Yu. E. Stepanova ◽  
E. E. Koren’ ◽  
...  
Keyword(s):  
Semiconductor Laser ◽  
Clinical Case ◽  
Anterior Commissure ◽  
Voice Quality ◽  
Laser Coagulation ◽  
Ktp Laser ◽  
Upper Respiratory Tract ◽  
Surgical Interventions ◽  
Relevant Today ◽  
Laser Systems

The issues of phonosurgery remain truly relevant today since there is a high prevalence of benign and tumor-like laryngeal formations among the pathology of the upper respiratory tract (up to 55–70%). Nowadays, laser technologies are coming to the fore among the possibilities of laryngological practice. Photoangiolytic lasers, such as the KTP laser, are actively used to coagulate subepithelial vessels without destroying the superficial epithelium. A novelty among laser systems is a laser with a wavelength of 445 nm certified in 2018, which combines high hemostatic and cutting effects without the extensive zone of thermal damage to surrounding tissues. This paper presents two clinical cases where a 445 nm laser is used. The first clinical case describes a patient with an anterior commissure scar after previous surgical interventions. Treatment using a 445 nm laser made it possible to dissect the scar and restore the normal laryngeal anatomy without stent placement. 5 weeks after the operation, the patient underwent phonopedic therapy and was satisfied with the voice quality. The second clinical case describes a patient with a cystic-like neoplasm of the left vocal fold. Dissection and enucleation of the formation using a direct micro laryngoscopy was done, followed by laser coagulation of the incision edges. Within 2 weeks, the patient showed restoration of the laryngeal endoscopic state and a voice improvement with normalization of acoustic parameters. Thus, the 445 nm semiconductor laser has shown in practice highly pronounced photoangiolytic and cutting properties, which proves its effectiveness in phonosurgery.

Analysis of Time-Delay Characteristic and Effective Bandwidth of Three Chaotic Semiconductor Laser Systems

2020 ◽  
Vol 57 (13) ◽  
pp. 131407
Author(s):  
刘蓬勃 Liu Pengbo ◽  
张胜海 Zhang Shenghai ◽  
张晓旭 Zhang Xiaoxu ◽  
吴天安 Wu Tianan
Keyword(s):  
Time Delay ◽  
Semiconductor Laser ◽  
Effective Bandwidth ◽  
Laser Systems
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