Optimization of Spectroscope Parameters for Single-beam Pulsed Laser Scanning Circumferential Detection System

2019 ◽  
Author(s):  
Yanliang Gao ◽  
Bingting Zha ◽  
Jinbo Huang ◽  
Hailu Yuan
Keyword(s):  
Laser Scanning ◽  
Detection System ◽  
Pulsed Laser ◽  
Single Beam

scholarly journals Heat impact during laser ablation extraction of mineralised tissue micropillars

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samuel McPhee ◽  
Alexander Groetsch ◽  
Jonathan D. Shephard ◽  
Uwe Wolfram
Keyword(s):  
Laser Ablation ◽  
Mechanical Testing ◽  
Laser Scanning ◽  
Pulsed Laser ◽  
Temperature Response ◽  
Collagen Fibre ◽  
Pulsed Laser Ablation ◽  
Collagen Molecules ◽  
Ultrashort Pulsed Laser ◽  
The Impact

AbstractThe underlying constraint of ultrashort pulsed laser ablation in both the clinical and micromachining setting is the uncertainty regarding the impact on the composition of material surrounding the ablated region. A heat model representing the laser-tissue interaction was implemented into a finite element suite to assess the cumulative temperature response of bone during ultrashort pulsed laser ablation. As an example, we focus on the extraction of mineralised collagen fibre micropillars. Laser induced heating can cause denaturation of the collagen, resulting in ultrastructural loss which could affect mechanical testing results. Laser parameters were taken from a used micropillar extraction protocol. The laser scanning pattern consisted of 4085 pulses, with a final radial pass being 22 $$\upmu {\text {m}}$$ μ m away from the micropillar. The micropillar temperature was elevated to 70.58 $$^{\circ }{\text {C}}$$ ∘ C , remaining 79.42 $$^{\circ }{\text {C}}$$ ∘ C lower than that of which we interpret as an onset for denaturation. We verified the results by means of Raman microscopy and Energy Dispersive X-ray Microanalysis and found the laser-material interaction had no effect on the collagen molecules or mineral nanocrystals that constitute the micropillars. We, thus, show that ultrashort pulsed laser ablation is a safe and viable tool to fabricate bone specimens for mechanical testing at the micro- and nanoscale and we provide a computational model to efficiently assess this.

scholarly journals Nonlinear absorption and scattering of a single plasmonic nanostructure characterized by x-scan technique

2019 ◽  
Vol 10 ◽  
pp. 2182-2191 ◽  
Author(s):  
Tushar C Jagadale ◽  
Dhanya S Murali ◽  
Shi-Wei Chu
Keyword(s):  
Laser Scanning ◽  
Detection System ◽  
Nonlinear Behavior ◽  
Optical Nonlinearity ◽  
Research Area ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Thin Sample ◽  
Channel Detection ◽  
Novel Method

Nonlinear nanoplasmonics is a largely unexplored research area that paves the way for many exciting applications, such as nanolasers, nanoantennas, and nanomodulators. In the field of nonlinear nanoplasmonics, it is highly desirable to characterize the nonlinearity of the optical absorption and scattering of single nanostructures. Currently, the common method to quantify optical nonlinearity is the z-scan technique, which yields real and imaginary parts of the permittivity by moving a thin sample with a laser beam. However, z-scan typically works with thin films, and thus acquires nonlinear responses from ensembles of nanostructures, not from single ones. In this work, we present an x-scan technique that is based on a confocal laser scanning microscope equipped with forward and backward detectors. The two-channel detection offers the simultaneous quantification for the nonlinear behavior of scattering, absorption and total attenuation by a single nanostructure. At low excitation intensities, both scattering and absorption responses are linear, thus confirming the linearity of the detection system. At high excitation intensities, we found that the nonlinear response can be derived directly from the point spread function of the x-scan images. Exceptionally large nonlinearities of both scattering and absorption are unraveled simultaneously for the first time. The present study not only provides a novel method for characterizing nonlinearity of a single nanostructure, but also reports surprisingly large plasmonic nonlinearities.

Design of High Sensitive Power Detection System for Pulsed Laser

2021 ◽  
Vol 58 (3) ◽  
pp. 0314005-314005235
Author(s):  
王秋卜 Wang Qiubu ◽  
刘文清 Liu Wenqing ◽  
张天舒 Zhang Tianshu ◽  
付毅宾 Fu Yibin
Keyword(s):  
Detection System ◽  
Pulsed Laser

Fabrication of large area superconducting thin film by pulsed laser scanning

1999 ◽  
Vol 9 (2) ◽  
pp. 2355-2358
Author(s):  
Q.L. Wang ◽  
C.W. An ◽  
W.D. Song ◽  
S.S. Oh ◽  
K.S. Ryu ◽  
...  
Keyword(s):  
Thin Film ◽  
Laser Scanning ◽  
Pulsed Laser ◽  
Large Area ◽  
Superconducting Thin Film

scholarly journals ORION: Clearing near-Earth space debris using a 20-kW, 530-nm, Earth-based, repetitively pulsed laser

1996 ◽  
Vol 14 (1) ◽  
pp. 1-44 ◽  
Author(s):  
C.R. Phipps ◽  
G. Albrecht ◽  
H. Friedman ◽  
D. Gavel ◽  
E.V. George ◽  
...  
Keyword(s):  
Space Debris ◽  
Detection System ◽  
Public Awareness ◽  
Phase Error ◽  
Laser System ◽  
Average Power ◽  
Pulsed Laser ◽  
Earth Space ◽  
Near Earth Space ◽  
Quantum Leap

When a large piece of space debris forced a change of flight plan for arecent U.S. Space Shuttle mission, the concept that we are trashing space as well as Earth finally attained broad public awareness. Almost a million pieces of debris have been generated by 35 years of spaceflight, and now threaten long-term space missions. The most economical solution to this problem is to cause space debris items to reenter and burn up in the atmosphere. For safe handling of large objects, it is desired to do this on a precomputed trajectory. Due to the number, speed, and spacial distribution of the objects, a highly agile source of mechanical impulse, as well as a quantum leap in detection capability are required. For reasons we will discuss, we believe that the best means of accomplishing these goals is the system we propose here, which uses a ground-based laser system and active beam phase error correcting beam director to provide the impulse, together with a new, computer-intensive, very high-resolution optical detection system to locate objects as small as 1 cm at 500-km range. Illumination of the objects by the repetitively pulsed laser produces a laser-ablation jet that gives the impulse to de-orbit the object. A laser of just 20-kW average power and state-of-the-art detection capabilities could clear near-Earth space below 100-km altitude of all space debris larger than 1 cm but less massive than 100 kg in about 4 years, and all debris in the threatening 1–20-cm size range in about 2 years of continuous operation. The ORION laser would be sited near the Equator at a high altitude location (e.g., the Uhuru site on Kilimanjaro), minimizing turbulence correction, conversion by stimulated Raman scattering, and absorption of the 530-nm wavelength laser beam. ORION is a special case of Laser Impulse Space Propulsion (LISP), studied extensively by Los Alamos and others over the past 4 years.

scholarly journals Molecular Dynamics in Solution Probed by the Transient Grating Method With a Nanosecond Pulsed Laser

1994 ◽  
Vol 13 (3-4) ◽  
pp. 169-185 ◽  
Author(s):  
Masahide Terazima ◽  
Koichi Okamoto ◽  
Noboru Hirota
Keyword(s):  
Molecular Dynamics ◽  
Detection System ◽  
Pulsed Laser ◽  
Photochemical Reactions ◽  
Molecular Volume ◽  
Transient Grating ◽  
Trans Form ◽  
Fast Detection ◽  
Nanosecond Pulsed Laser ◽  
Cis And Trans

Molecular dynamics in organic solution is investigated by the transient grating method with a nanosecond pulsed laser and a fast detection system. First, the dynamics of methyl red (MR) is studied for the probe of the translational diffusion process of solution. The origin of the TG signal which represents the mass diffusion is attributed to the phase grating created by the different refractive indices of the cis and trans forms. The cis form of MR, which has a slightly smaller molecular volume than the trans form is found to diffuse more slowly in alcoholic and aldehyde solutions. The measured diffusion coefficients (D) are compared with theoretically calculated values. Second, the TG method is applied to elucidate the dynamics of transient radicals created by photochemical reactions. The determined D of the radicals are about 3∼4 times smaller than those of the parent non-radical molecules even though the molecular volumes are similar to each other. The advantages as well as the disadvantages of the TG method for elucidating the solvent dynamics are discussed.

Sign in / Sign up

Export Citation Format

Share Document