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RSS2022 Vol. 34, No. 1
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2022,
34: 1-2.
2022,
34: 011001.
doi: 10.11884/HPLPB202234.210357
Abstract:
Laser driven dynamic compression experiments play the central role in extreme pressure and density research, and are important to a number of fields, including planetary geophysics, material science, and inertial confinement fusion, benefit to improve understandings of properties of materials at extreme conditions and their applications. Recently laser driven compression techniques have been developing quickly together with laser facility, laser plasma interaction, target fabrication and diagnostic techniques. On contrast to other loading platform, it is good at ramp compression, decaying shock compression and complex loading path, and allows micro-scale probe combined with macro-scale measurements, ultra-high pressure and strain rate. This review summarizes this technique from the aspects of thermodynamics of compression, laser drive mechanism, laser drive experimental techniques and recent advances of extreme compression of materials.
Laser driven dynamic compression experiments play the central role in extreme pressure and density research, and are important to a number of fields, including planetary geophysics, material science, and inertial confinement fusion, benefit to improve understandings of properties of materials at extreme conditions and their applications. Recently laser driven compression techniques have been developing quickly together with laser facility, laser plasma interaction, target fabrication and diagnostic techniques. On contrast to other loading platform, it is good at ramp compression, decaying shock compression and complex loading path, and allows micro-scale probe combined with macro-scale measurements, ultra-high pressure and strain rate. This review summarizes this technique from the aspects of thermodynamics of compression, laser drive mechanism, laser drive experimental techniques and recent advances of extreme compression of materials.
2022,
34: 011002.
doi: 10.11884/HPLPB202234.210275
Abstract:
Pulsed laser ablation propulsion has the characteristics of high specific impulse and precise and controllable thrust. It can be used not only for launching payload, but also for satellite drive, even for deflecting the orbit of asteroid, whose surface material would be ablated as propellant. Therefore, pulsed laser ablation propulsion has attracted more and more attention in the aerospace field. Focusing on laser launch vehicle of single stage to orbit, transmission to geosynchronous orbit and Mars orbit; laser plasma thrusters for the attitude and orbit control of spacecraft, laser-electric hybrid acceleration systems; laser ablation for orbit manipulation of centimeter scale space debris and attitude manipulation of larger space debris; laser ablation for deflecting the orbit of asteroid, this paper systematically and comprehensively summarizes the research status and progress of pulsed laser ablation propulsion technology in the field of aerospace, and analyzes in detail the key problems such as the average power, wavelength, pulse width of laser and the selection of propellant.
Pulsed laser ablation propulsion has the characteristics of high specific impulse and precise and controllable thrust. It can be used not only for launching payload, but also for satellite drive, even for deflecting the orbit of asteroid, whose surface material would be ablated as propellant. Therefore, pulsed laser ablation propulsion has attracted more and more attention in the aerospace field. Focusing on laser launch vehicle of single stage to orbit, transmission to geosynchronous orbit and Mars orbit; laser plasma thrusters for the attitude and orbit control of spacecraft, laser-electric hybrid acceleration systems; laser ablation for orbit manipulation of centimeter scale space debris and attitude manipulation of larger space debris; laser ablation for deflecting the orbit of asteroid, this paper systematically and comprehensively summarizes the research status and progress of pulsed laser ablation propulsion technology in the field of aerospace, and analyzes in detail the key problems such as the average power, wavelength, pulse width of laser and the selection of propellant.
2022,
34: 011003.
doi: 10.11884/HPLPB202234.210326
Abstract:
With the rapid development of high-power density laser, the laser driven explosion and shock waves have attracted great attention in recent years. In this paper, the progress of laser driven explosion and shock waves, involving the laser explosive loading characteristics and the scaling law, the laser shock peening of material, the dynamic phase-transformation behavior of materials under laser shock, and the laser-induced micro-bullet impact, is reviewed.
With the rapid development of high-power density laser, the laser driven explosion and shock waves have attracted great attention in recent years. In this paper, the progress of laser driven explosion and shock waves, involving the laser explosive loading characteristics and the scaling law, the laser shock peening of material, the dynamic phase-transformation behavior of materials under laser shock, and the laser-induced micro-bullet impact, is reviewed.
2022,
34: 011004.
doi: 10.11884/HPLPB202234.210331
Abstract:
Optics are indispensable components for realizing optical functions of various laser systems, and their performances determine the output capability and beam quality of the laser system. Laser damage of optics have accompanied the developments of laser technologies since the invention of laser. With the development of new laser technologies and tractions of new laser applications, laser parameters such as the wavelength, pulse width and repetition frequency have been expanded, making laser damage more complicated. However, remaining essentially the same, the core of laser damage is the absorption mechanism of optics or optical materials. Starting from the basic principles of the interaction between laser and optical materials, this paper focuses on the typical optical materials and optics used in domestic inertial confinement fusion (ICF) laser drivers, and reviews the scientific research on laser damage of optics. Then, it summarizes the key technologies and milestone progress formed during this period. At last, it predicts several types of bottleneck optics that still plagued this field as well as the development of further research.
Optics are indispensable components for realizing optical functions of various laser systems, and their performances determine the output capability and beam quality of the laser system. Laser damage of optics have accompanied the developments of laser technologies since the invention of laser. With the development of new laser technologies and tractions of new laser applications, laser parameters such as the wavelength, pulse width and repetition frequency have been expanded, making laser damage more complicated. However, remaining essentially the same, the core of laser damage is the absorption mechanism of optics or optical materials. Starting from the basic principles of the interaction between laser and optical materials, this paper focuses on the typical optical materials and optics used in domestic inertial confinement fusion (ICF) laser drivers, and reviews the scientific research on laser damage of optics. Then, it summarizes the key technologies and milestone progress formed during this period. At last, it predicts several types of bottleneck optics that still plagued this field as well as the development of further research.
2022,
34: 011005.
doi: 10.11884/HPLPB202234.210336
Abstract:
Thermal effect is one of the important factors affecting the safe operation of high-power fiber laser system. Exploring the source of thermal effect of optical fiber laser system, actively carrying out research on heat-control technology, taking reasonable measures to suppress heat concentration, and greatly improving the mode instability threshold of optical fiber laser system to avoid mode degradation, are of great practical significance to further improve the safe and stable output power of optical fiber laser system. Taking widely-used concentrated end-pumping technology as an example, this paper summarizes the main sources of thermal effect of high-power continuous-wave fiber laser system, and puts forward practical solutions and reasonable suggestions for different thermal effects. Finally, this paper focuses on long-distance distributed side-pumping technology and pump-gain integrated functional fiber, and looks forward to the future development of 10 kW-level ultra-high power fiber laser.
Thermal effect is one of the important factors affecting the safe operation of high-power fiber laser system. Exploring the source of thermal effect of optical fiber laser system, actively carrying out research on heat-control technology, taking reasonable measures to suppress heat concentration, and greatly improving the mode instability threshold of optical fiber laser system to avoid mode degradation, are of great practical significance to further improve the safe and stable output power of optical fiber laser system. Taking widely-used concentrated end-pumping technology as an example, this paper summarizes the main sources of thermal effect of high-power continuous-wave fiber laser system, and puts forward practical solutions and reasonable suggestions for different thermal effects. Finally, this paper focuses on long-distance distributed side-pumping technology and pump-gain integrated functional fiber, and looks forward to the future development of 10 kW-level ultra-high power fiber laser.
2022,
34: 011006.
doi: 10.11884/HPLPB202234.210334
Abstract:
In recent years, the space debris has posed severe threat for aerospace applications. Active removal of space debris has been extensively investigated to preserve the sustainable development of space resources and maintain the safety of spacecrafts. In this paper, the origin and development of space debris problem is studied, and the characteristics of different active removal techniques are discussed. Besides, the technical difficulties and the scientific problem of space debris removal by using pulsed laser system is further studied, and the development of the method is reviewed. At last, this paper suggests potential development of space-based laser for removing space debris in the future.
In recent years, the space debris has posed severe threat for aerospace applications. Active removal of space debris has been extensively investigated to preserve the sustainable development of space resources and maintain the safety of spacecrafts. In this paper, the origin and development of space debris problem is studied, and the characteristics of different active removal techniques are discussed. Besides, the technical difficulties and the scientific problem of space debris removal by using pulsed laser system is further studied, and the development of the method is reviewed. At last, this paper suggests potential development of space-based laser for removing space debris in the future.
2022,
34: 011007.
doi: 10.11884/HPLPB202234.210530
Abstract:
High-energy lasers are widely used in materials processing, scientific research, space debris removal, and military counter measures. In recent years, various types of diode-pumped high-energy lasers with high power, high efficiency, and high beam quality have been rapidly developed due to their compact structure, simple system, full electric drive, and unlimited magazines. In this review, we describe in detail the research progress of high-average power bulk solid-state lasers, high-power visible light lasers, high-peak power lasers, high-power fiber lasers, alkali metal vapor lasers and other diode-pumped high-energy lasers at home and abroad. Moreover, we conclude with some perspectives and outlook on their future developments.
High-energy lasers are widely used in materials processing, scientific research, space debris removal, and military counter measures. In recent years, various types of diode-pumped high-energy lasers with high power, high efficiency, and high beam quality have been rapidly developed due to their compact structure, simple system, full electric drive, and unlimited magazines. In this review, we describe in detail the research progress of high-average power bulk solid-state lasers, high-power visible light lasers, high-peak power lasers, high-power fiber lasers, alkali metal vapor lasers and other diode-pumped high-energy lasers at home and abroad. Moreover, we conclude with some perspectives and outlook on their future developments.
2022,
34: 011008.
doi: 10.11884/HPLPB202234.210296
Abstract:
This paper discusses the thermal effects of optical components and media gas in inner propagation of high energy laser system, which is very important for the performance. The thermal aberration models of optical components and media gas, the influencing factors, and the changing laws are introduced. For optical components, some physical factors are emphatically analyzed, including absorptivity, characters of the materials, and laser spot distributions. The results show that the level of thermal aberrations depends on the absorptivity, and spatio-temporal characters depends on the material and the distribution of laser spot. For media gas, the variation of thermal aberrations depend on switch of physical mechanism, heat conduction and heat convection for temperature increment, and the law of time dependent thermal aberrations are studied carefully. Methods and measures of reducing thermal effect are introduced for closed and opened system. The multi-physical module of a software named Easylaser is introduced and is used to simulate the thermal effects of a laser inner propagation, including reflective mirrors, a optical window, a spectroscope, and media gas. The results show that the aberrations between reflective mirrors and the optical window, and between gas and the optical windows could be complementary. The characters of laser spot in far-field are also simulated. All the results demonstrate that Easylaser can be used to simulate and analyse the thermal effects in high power laser system.
This paper discusses the thermal effects of optical components and media gas in inner propagation of high energy laser system, which is very important for the performance. The thermal aberration models of optical components and media gas, the influencing factors, and the changing laws are introduced. For optical components, some physical factors are emphatically analyzed, including absorptivity, characters of the materials, and laser spot distributions. The results show that the level of thermal aberrations depends on the absorptivity, and spatio-temporal characters depends on the material and the distribution of laser spot. For media gas, the variation of thermal aberrations depend on switch of physical mechanism, heat conduction and heat convection for temperature increment, and the law of time dependent thermal aberrations are studied carefully. Methods and measures of reducing thermal effect are introduced for closed and opened system. The multi-physical module of a software named Easylaser is introduced and is used to simulate the thermal effects of a laser inner propagation, including reflective mirrors, a optical window, a spectroscope, and media gas. The results show that the aberrations between reflective mirrors and the optical window, and between gas and the optical windows could be complementary. The characters of laser spot in far-field are also simulated. All the results demonstrate that Easylaser can be used to simulate and analyse the thermal effects in high power laser system.
2022,
34: 011009.
doi: 10.11884/HPLPB202234.210321
Abstract:
To study the influence of pulse width on the damage threshold of HgCdTe material irradiated by mid-infrared in-band laser pulse, a one-dimensional model named self-consistent model is established. Some parameters including number density of carrier, carrier and energy current, temperature of carrier and lattice are calculated in the whole process. Damage thresholds of in-band single pulsed laser, whose wavelength is 2.85 μm and pulse width ranges from 30 ps to 10 ns, are obtained. The results show that, damage threshold rauge of in-band laser is 200−500 mJ/cm2. Among them, the damage threshold of 300 ps to 3 ns laser pulses is about 200 mJ/cm2, which is lower than that of other pulsed lasers. The validity of simulation model is verified by setting up the experimental devices and carrying out relevant experiments. Using a single pulsed laser with wavelength of 2.85 μm and pulse width of 300 ps as the light source, the damage threshold is about 200 mJ/cm2. Under the same conditions, when 10 ns single laser pulse is used, the damage threshold is greater than 474 mJ/cm2. The damage process of the HgCdTe material destroyed by hundred-picosecond pulsed laser combines thermal and optical breakdown effects, and its unique mechanism aggravates the destruction of material.
To study the influence of pulse width on the damage threshold of HgCdTe material irradiated by mid-infrared in-band laser pulse, a one-dimensional model named self-consistent model is established. Some parameters including number density of carrier, carrier and energy current, temperature of carrier and lattice are calculated in the whole process. Damage thresholds of in-band single pulsed laser, whose wavelength is 2.85 μm and pulse width ranges from 30 ps to 10 ns, are obtained. The results show that, damage threshold rauge of in-band laser is 200−500 mJ/cm2. Among them, the damage threshold of 300 ps to 3 ns laser pulses is about 200 mJ/cm2, which is lower than that of other pulsed lasers. The validity of simulation model is verified by setting up the experimental devices and carrying out relevant experiments. Using a single pulsed laser with wavelength of 2.85 μm and pulse width of 300 ps as the light source, the damage threshold is about 200 mJ/cm2. Under the same conditions, when 10 ns single laser pulse is used, the damage threshold is greater than 474 mJ/cm2. The damage process of the HgCdTe material destroyed by hundred-picosecond pulsed laser combines thermal and optical breakdown effects, and its unique mechanism aggravates the destruction of material.
2022,
34: 011010.
doi: 10.11884/HPLPB202234.210342
Abstract:
This paper presents the computational studies on the effect and mechanism of strong light interference in the large aperture static interference imaging spectrometer. First, we generated images with simplified ground targets and computed the corresponding original interference imaging pattern. Then, we simulated a 830 nm single-wavelength laser and a super continuum laser respectively, to analyze the typical interference effects. During the process, it was assumed that the original spectral information could be resolved only when the spectral angle is lower than 30°. For the 830 nm laser interference, the spectral angle would reach 30° when the ratio of laser interference imaging peak to the target imaging peak was 0.2∶1, but the interference effect could be effectively filtered by the 830 nm filter. In the case of super continuum laser interference, the spectral angle was finally stabilized at 21° without considering the saturation threshold, but the detector could be oversaturated more easily. Overall, both 830 nm laser and super continuum laser can disable the spectrum recovery process, but the mechanisms are different since the former one shifts the characteristic peak of the spectrum and the latter makes the interference fringes unrecognizable.
This paper presents the computational studies on the effect and mechanism of strong light interference in the large aperture static interference imaging spectrometer. First, we generated images with simplified ground targets and computed the corresponding original interference imaging pattern. Then, we simulated a 830 nm single-wavelength laser and a super continuum laser respectively, to analyze the typical interference effects. During the process, it was assumed that the original spectral information could be resolved only when the spectral angle is lower than 30°. For the 830 nm laser interference, the spectral angle would reach 30° when the ratio of laser interference imaging peak to the target imaging peak was 0.2∶1, but the interference effect could be effectively filtered by the 830 nm filter. In the case of super continuum laser interference, the spectral angle was finally stabilized at 21° without considering the saturation threshold, but the detector could be oversaturated more easily. Overall, both 830 nm laser and super continuum laser can disable the spectrum recovery process, but the mechanisms are different since the former one shifts the characteristic peak of the spectrum and the latter makes the interference fringes unrecognizable.
2022,
34: 011011.
doi: 10.11884/HPLPB202234.210329
Abstract:
To predict the failure time of carbon fiber/ epoxy resin reinforced composite laminates under the combined action of laser and mechanical load, different laser power density (70–210 W/cm2), different pre-stress levels (50% and 70% of tensile strength) were studied experimentally. The failure mechanism of 2 mm laminates under different spot sizes (70% and 100% of the width of tensile specimens) was obtained, and the influence rule of different influencing factors on fracture time was obtained. The results show that the failure mechanism of pre-loaded laminates is the pyrolysis of the substrate material of epoxy resin, the oxidation fracture of the fiber and the brittle fracture of the residual structure of the back surface. Under certain pre-stress conditions, the fracture time and the irradiated laser power density are exponential. The pre-stress level has a significant effect on the fracture time.
To predict the failure time of carbon fiber/ epoxy resin reinforced composite laminates under the combined action of laser and mechanical load, different laser power density (70–210 W/cm2), different pre-stress levels (50% and 70% of tensile strength) were studied experimentally. The failure mechanism of 2 mm laminates under different spot sizes (70% and 100% of the width of tensile specimens) was obtained, and the influence rule of different influencing factors on fracture time was obtained. The results show that the failure mechanism of pre-loaded laminates is the pyrolysis of the substrate material of epoxy resin, the oxidation fracture of the fiber and the brittle fracture of the residual structure of the back surface. Under certain pre-stress conditions, the fracture time and the irradiated laser power density are exponential. The pre-stress level has a significant effect on the fracture time.
2022,
34: 011012.
doi: 10.11884/HPLPB202234.210338
Abstract:
To explore laser induced thermal injure in skin tissue, 1064 nm laser induced thermal injure in mice skin with different laser duration was studied by experimental and theoretical analysis methods. Dermoscope images and optical coherence tomography images were used to assess the degree of thermal injure in biological skin tissue. Arrhenius thermal injure equation was used to calculate thermal damage parameters and establish a laser induced thermal injure model of skin tissue, then compared with experimental results. The results show that under the 1064 nm laser irradiation with 30 W/mm2 power density, there was reversible damage in the mouse skin tissue within 0 to 100 ms laser duration; the mice skin tissue appeared edema and thermal coagulation injure within 150 to 280 ms laser duration; during the laser duration of 280 to 550 ms, the epidermis of the mice skin was vaporized, eschars appeared around the damage spot, and the dermis was degenerated. Over 660 ms laser duration, the epidermis and dermis of the mice skin were vaporized, tissue fluid was exuded from the wound and the subcutaneous tissue was degenerated. The theoretical analysis is consistent with the experimental results. The established thermal injury model can verify the degree of thermal injury in mice skin.
To explore laser induced thermal injure in skin tissue, 1064 nm laser induced thermal injure in mice skin with different laser duration was studied by experimental and theoretical analysis methods. Dermoscope images and optical coherence tomography images were used to assess the degree of thermal injure in biological skin tissue. Arrhenius thermal injure equation was used to calculate thermal damage parameters and establish a laser induced thermal injure model of skin tissue, then compared with experimental results. The results show that under the 1064 nm laser irradiation with 30 W/mm2 power density, there was reversible damage in the mouse skin tissue within 0 to 100 ms laser duration; the mice skin tissue appeared edema and thermal coagulation injure within 150 to 280 ms laser duration; during the laser duration of 280 to 550 ms, the epidermis of the mice skin was vaporized, eschars appeared around the damage spot, and the dermis was degenerated. Over 660 ms laser duration, the epidermis and dermis of the mice skin were vaporized, tissue fluid was exuded from the wound and the subcutaneous tissue was degenerated. The theoretical analysis is consistent with the experimental results. The established thermal injury model can verify the degree of thermal injury in mice skin.
2022,
34: 011013.
doi: 10.11884/HPLPB202234.210257
Abstract:
Laser-ablation plasma has been regarded as a novel approach for providing high velocity loading in experiment. Axial jet velocity of km/s even higher than 5 km/s could be achieved by employing laser-driven plasma method. On the other side , a wide range of jet temperature and plasma density could also be obtained during the loading process. This paper presents an experimental method to investigate the super high-velocity impact of solid target with gas. A high energy laser-ablation plasma device was established in this work, and plasma with jet velocity above 10 km/s was generated during the experiment. The aerodynamic characteristics of the high-velocity object’s interaction with gas were studied in the experiment. The results of prove that, this work, the method has great potential for applications in the research of many fields including astrophysics, asteroid morphology, and the interaction of aerolith with atmosphere.
Laser-ablation plasma has been regarded as a novel approach for providing high velocity loading in experiment. Axial jet velocity of km/s even higher than 5 km/s could be achieved by employing laser-driven plasma method. On the other side , a wide range of jet temperature and plasma density could also be obtained during the loading process. This paper presents an experimental method to investigate the super high-velocity impact of solid target with gas. A high energy laser-ablation plasma device was established in this work, and plasma with jet velocity above 10 km/s was generated during the experiment. The aerodynamic characteristics of the high-velocity object’s interaction with gas were studied in the experiment. The results of prove that, this work, the method has great potential for applications in the research of many fields including astrophysics, asteroid morphology, and the interaction of aerolith with atmosphere.
