Laser beam direct writing of fine lines of alpha-Fe2O3 from metalorganic spin-coated films and transient behavior study of laser decomposition process

1994 ◽  
Vol 33 (7) ◽  
pp. 2442 ◽  
Author(s):  
Songsheng Xue
Keyword(s):  
Laser Beam ◽  
Transient Behavior ◽  
Decomposition Process ◽  
Direct Writing ◽  
Behavior Study

scholarly journals Automated Indirect Transportation of Biological Cells with Optical Tweezers and a 3D Printed Microtool

2019 ◽  
Vol 9 (14) ◽  
pp. 2883 ◽  
Author(s):  
Songyu Hu ◽  
Heng Xie ◽  
Tanyong Wei ◽  
Shuxun Chen ◽  
Dong Sun
Keyword(s):  
Laser Beam ◽  
Optical Tweezers ◽  
High Precision ◽  
Optical Tweezer ◽  
Cell Manipulation ◽  
Laser Exposure ◽  
Direct Writing ◽  
Negative Effects ◽  
Direct Exposure ◽  
Direct Cell

Optical tweezers are widely used for noninvasive and precise micromanipulation of living cells to understand biological processes. By focusing laser beams on cells, direct cell manipulation with optical tweezers can achieve high precision and flexibility. However, direct exposure to the laser beam can lead to negative effects on the cells. These phenomena are also known as photobleaching and photodamage. In this study, we proposed a new indirect cell micromanipulation approach combined with a robot-aided holographic optical tweezer system and 3D nano-printed microtool. The microtool was designed with a V-shaped head and an optical handle part. The V-shaped head can push and trap different sizes of cells as the microtool moves forward by optical trapping of the handle part. In this way, cell exposure to the laser beam can be effectively reduced. The microtool was fabricated with a laser direct writing system by two-photon photopolymerization. A control strategy combined with an imaging processing algorithm was introduced for automated manipulation of the microtool and cells. Experiments were performed to verify the effectiveness of our approach. First, automated microtool transportation and rotation were demonstrated with high precision. Second, indirect optical transportations of cells, with and without an obstacle, were performed to demonstrate the effectiveness of the proposed approach. Third, experiments of fluorescent cell manipulation were performed to confirm that, indicated by the photobleaching effect, indirect manipulation with the microtool could induce less laser exposure compared with direct optical manipulation. The proposed method could be useful in complex biomedical applications where precise cell manipulation and less laser exposure are required.

Laser emission from diode-pumped Nd:YAG cladding waveguides obtained by direct writing with a femtosecond-laser beam

2014 ◽  
Author(s):  
Gabriela Salamu ◽  
Flavius Voicu ◽  
Florin Jipa ◽  
Marian Zamfirescu ◽  
Traian Dascalu ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Beam ◽  
Laser Emission ◽  
Direct Writing ◽  
Femtosecond Laser Beam ◽  
Diode Pumped

A Comparison of Characteristics of Periodic Surface Micro/Nano Structures Generated Via Single Laser Beam Direct Writing and Particle Lens Array Parallel Beam Processing

2021 ◽  
Author(s):  
Fatema Rajab ◽  
Anmar K. Al-Jumaily ◽  
Tayf Tariq A.S ◽  
Sorin Laurentiu Stanescu ◽  
Ahmad W. AlShaer ◽  
...  
Keyword(s):  
Laser Beam ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Periodic Surface ◽  
Lens Array ◽  
Single Beam ◽  
Beam Laser ◽  
Nano Structures ◽  
Single Laser ◽  
Surface Patterns

Abstract Changing material surface micro/nano structures using laser beam texturing is a valuable approach in wide applications such as control of cell/bacterial adhesion and proliferation, solar cells and optical metamaterials. Here we report a comparison of the characteristics of surface micro/nano structures produced using single beam laser direct writing and particle lens array parallel laser beam patterning. A Nd:YVO4 nanosecond pulsed laser at 532 nm wavelength was used in the laser direct writing method to texture the stainless steel surface submerged in water and in air with different scanning patterns. Changes in surface morphology, wettability, surface chemistry and optical reflectivity were analyzed. In the particle lens array method, an excimer nanosecond laser at 248 nm wavelength was adopted to produce surface patterns on GeSbTe (GST) film coated on a polycarbonate substrate by splitting and focusing a single laser beam into millions of parallel breams. Single beam laser direct writing shows that the surface of high roughness and oxygen percentage content presented high wettability and low reflectivity characteristics. However, the controllability of the type of surface micro/nano patterns is limited. The parallel laser beam processing using particle lens array allows rapid production of user designed periodic surface patterns at nano-scale overcoming the optical diffraction limit with a high degree of controllability. Controlling the uniformity of the particle lens array is a challenge.

Laser Stimulated Deposition of GaAs, GaAsP and GaAsP-GaAs Superlattices

1986 ◽  
Vol 75 ◽  
Author(s):  
N. H. Karam ◽  
S. M. Bedair ◽  
N. A. El-Masry ◽  
D. Griffis
Keyword(s):  
Laser Beam ◽  
Growth Conditions ◽  
Direct Writing ◽  
Gaas Substrates ◽  
Laser Beam Irradiation ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Potential Applications ◽  
Ion Laser ◽  
Deposited Films

AbstractAn Ar+ ion laser has been used for direct writing of GaAs and GaAsP single crystal films on thermally biased GaAs substrates. Multiple scanning of the laser beam at speeds in the range 100–200 μm/s at carefully selected growth conditions resulted in single crystalline selectively deposited films. Photoluminescence indicates that these deposited films have optical properties that are comparable with the conventionally (MOCVD) grown material. Laser beam irradiation has been used to form a superlattice (SL) structure which has been demonstrated in the GaAsP-GaAs system. When a GaAs substrate is exposed to fluxes of AsH3, PH3 and TMG at 500°C, only GaAs will be deposited because of the insufficient cracking of PH3. However, localized laser heating results in GaAsP deposition. A GaAsP-GaAs superlattice with a period of about 400 Å has been synthesized. This laser induced technique can thus have potential applications in the generation of abrupt interfaces without the use of shutters as in MBE or gas switching as in MOCVD.

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