High-performance laser frequency stabilization scheme of Shandong University Institute of Oceanography

Combining the unique advantages of fiber waveguide and random laser, fiber random laser has rapidly developed into an important way to obtain high time-domain stability, high spatial brightness, low coherence and high power laser beams in recent years.

The high-intensity laser, characterized by ultra-short pulse and ultra-high peak power, provides unprecedented experimental means and extreme physical conditions for human beings, and has a wide range of application needs in major scientific and technological frontier fields such as advanced manufacturing, high-order harmonic generation, particle acceleration, and ultra-high-speed phenomenon research.

With its high output power, high beam quality and stable and compact system structure, the mid-infrared fiber laser light source with rare earth ion doped fiber as the gain medium has broad application prospects in the fields of medical treatment and cutting-edge scientific research. The erbium-doped fluoride fiber system has two important mid-infrared emission bands of 2.8 μm and 3.5 μm, which has become an important research direction in the field of mid-infrared laser technology due to its convenience of compatibility with semiconductor laser direct pumping and mature fiber material foundation. In this paper, the recent research progress of mid-infrared continuous-wave erbium-doped fluoride fiber lasers is systematically reviewed, and the representative research results on the improvement of output power and efficiency and the expansion of operating wavelength are reviewed and reviewed, and the future development trend of mid-infrared erbium-doped fluoride fiber lasers is briefly prospected around the bottleneck constraints at this stage.

Designing high-performance fibers is an important part of increasing the power of high-power fiber lasers. In order to solve the problem of digital design of complex optical fiber structures, SeeNano, a simulation software for the design of optical fiber waveguide structures, was preliminarily developed on the basis of the theory of fiber optics.

With its high output power, high beam quality and stable and compact system structure, the mid-infrared fiber laser light source with rare earth ion doped fiber as the gain medium has broad application prospects in the fields of medical treatment and cutting-edge scientific research. The erbium-doped fluoride fiber system has two important mid-infrared emission bands of 2.8 μm and 3.5 μm, which has become an important research direction in the field of mid-infrared laser technology due to its convenience of compatibility with semiconductor laser direct pumping and mature fiber material foundation. In this paper, the recent research progress of mid-infrared continuous-wave erbium-doped fluoride fiber lasers is systematically reviewed, and the representative research results on the improvement of output power and efficiency and the expansion of operating wavelength are reviewed and reviewed, and the future development trend of mid-infrared erbium-doped fluoride fiber lasers is briefly prospected around the bottleneck constraints at this stage.

High-power fiber lasers are widely used in many fields due to their advantages of high conversion efficiency, stable performance, good beam quality and compact structure.

The performance of pulsed single-frequency fiber amplifiers in terms of laser power, energy, linewidth, and beam quality has been greatly improved. Peak power of up to 100 kW and pulse energy in the millijoule range have been demonstrated. For further development, the appropriate balance between laser gain and different nonlinear effects and laser beam quality should be considered. New gain fiber designs, manipulation of pulse characteristics in the time and frequency domains, and combinations of fiber and solid-state laser amplifiers can be further explored to achieve new milestones in the development of high-performance pulsed single-frequency fiber lasers.

Signal processing block diagram

The signal is demodulated using internal and external native oscillators

Sawtooth or triangular resonance scanning

Use the built-in oscilloscope to observe signals at different locations during signal processing

Use the "click-to-lock" function to quickly lock to any zero crossing point of the error signal

Up to fourth-order low-pass IIR infinite impulse response filter demodulation signals

Individually configurable high-bandwidth and low-bandwidth PID controllers are used for high-frequency and low-frequency feedback

Use the Scan Lock in Range function to observe signals related to the scan voltage

The 1064nm high-power laser is a compact all-in-one design semiconductor laser with the characteristics of high output power and good stability. The laser integrates high-power drive, temperature control and water cooling, which greatly reduces the impact of temperature on laser stability and is easy to use, making your work more efficient!

The power density of high-power femtosecond laser focusing is very large, which can easily induce molecular valence bond cleavage and atomic ionization of almost any material, and the irreversible changes in state and physical properties such as phase transformation caused by this provide a physical basis for ultrafast laser material processing. Due to its high intensity, ultrafast laser processing has a broad spectrum of materials for a wide range of materials, including diamonds, sapphires, glass, semiconductors, metals, ceramics and polymers. Since the excitation process is ultra-fast, thermal relaxation is avoided, making ultrafast excitation a quasi-adiabatic process.

The safety level of the laser is classified according to the degree of damage to the human body caused by the laser produced by the laser. LASERS ARE CLASSIFIED FROM CLASS I (NON-DAMAGING) TO CLASS IV LASERS.

Guided by the major needs of the country, led by the frontier of international marine science and technology, and based on the micro-system chip of marine sensors based on optoelectronic integration, the marine sensor research team develops emerging disciplines involving cross-field cross-integration such as electronic science and technology, optical engineering, marine biology, marine chemistry, mechanical manufacturing, detection technology and automatic control, artificial intelligence and robot learning.

Cats playing together not only bring joy and entertainment, but also provide many therapeutic benefits to humans. These playful creatures have a special way of brightening up our lives, improving our emotional well-being, and reminding us to embrace the simple pleasures of life.

Laser pointers are valuable presentation tools, but it's also important to understand laser safety regulations. Many countries have limits on the power output of laser pointers to protect users and prevent accidents. It is advisable to check local regulations and choose a laser pointer that meets safety standards. Also, be careful when using a laser pointer and avoid pointing it directly at the person's eyes. The safety of the audience should be paramount.

Optical imaging technology has become a widely used microscopic imaging technology with the characteristics of non-contact measurement, no damage to the sample, high spatiotemporal resolution and high detection sensitivity. The fluorescent labeled imaging method has the advantages of high acquisition sensitivity and a wide variety of fluorescent labels, and is widely used in the biomedical field. However, its application is limited by its interference and photobleaching. Based on infrared spectroscopy and Raman spectroscopy microscopy technology to detect the natural vibration frequency of sample molecules, biological samples do not need to be pre-labeled, and directly use the characteristic spectral signal as imaging contrast, which has the advantages of molecular feature selectivity, and it has been widely used in biomedical microscopy, such as live cell, tissue or DNA imaging. However, the molecular spectral signal intensity is weak, which limits the detection sensitivity, laser power and data acquisition. Coherent Anti-Stokes Raman Scattering (CARS), which is also based on molecular vibrational energy levels, is a third-order nonlinear optical process, which produces a strong stimulated resonance signal and a certain directionality, which makes the CARS signal collection more efficient.

The SIG P365 9mm is a very popular semi-automatic pistol known for its compact size, high capacity, and excellent reliability. It quickly earned a reputation for concealing carry power, making it a favorite choice for firearms enthusiasts and professionals alike. While the SIG P365 already offers a high level of accuracy, the addition of a laser pointer can further enhance its shooting capabilities.

Presentations have become an integral part of our daily lives, whether in the classroom, conference room, or meeting. To enhance our ability to deliver impactful presentations, we are constantly making technological advancements. One of the most popular and remarkable devices is the Constant Light laser pointer.

The xkcd laser pointer is a fictional device introduced in Randall Munroe's webcomic "Laser Pointer". The comic humorously proposes a laser pointer that, instead of emitting a beam of light, projects the physical object it touches. This imaginative concept takes advantage of the idea of expanding the ability of traditional laser pointers to interact with the physical world, shattering popular expectations.

In the world of advanced laser technology, the fire arc laser pointer stands out as a revolutionary device that has forever changed the way precise aiming is done. With an innovative design and state-of-the-art features, this cutting-edge device offers unmatched accuracy and versatility. Whether it's for military use, law enforcement agencies, or outdoor recreational activities, the Arc of Fire laser pointer is the ultimate tool for those looking for superior aiming capabilities.

In 2004, at least 4 different units in the world published the research results of kW-class fiber lasers. At that time, the research work of high-power fiber lasers in China had just started [1]. Searching CNKI, the more representative research results include researchers from the Shanghai Institute of Optics and Mechanics of the Chinese Academy of Sciences and Tsinghua University who have achieved (several) ten-watt lasers based on ytterbium-doped fibers [2,3], and a joint research group of the Shanghai Institute of Optics and Mechanics of the Chinese Academy of Sciences and Shanghai Jiao Tong University based on fiber laser frequency doubling to generate 59mW green light [4]; In addition, in 2003, researchers from the Xi'an Institute of Optics and Mechanics of the Chinese Academy of Sciences realized a 400 mW laser based on cladding-pumped erbium-ytterbium co-doped fibers [5], among others. It can be seen that there was a clear gap between China's research achievements and the advanced level at that time.

When powering a laser pointer, the choice of battery is critical to ensure optimal performance and longevity. The 18650 battery is favored by laser pointer enthusiasts for its high capacity and good compatibility. In this comprehensive guide, we'll explore the best 18650 batteries on the market and provide expert insights to help you make an informed decision.

In order to systematically review the development process of China's high-power fiber laser, comprehensively collect the latest high-level research results of relevant research units in China, and promote the research and judgment of development strategy, China Laser published a special topic of "high-power fiber laser" in the 19th issue of 2024 (October).

When it comes to technological marvels, laser pointers are often overlooked. Often used for presentations or classroom lectures, these small handheld devices have a surprising feature that many people don't know about – they can burn paper. The purpose of this article is to explore the scientific principles behind the phenomenon of laser pointer burning paper and its practical implications, as well as to provide an expert perspective on the topic.

Qiu Min's research group at the Future Industry Research Center of Westlake University and the School of Engineering has successfully developed a new silicon carbide photonic device, which can effectively reduce the thermal drift problem in high-power laser processing. The team used semiconductor technology to fabricate large-aperture, high-precision 4H-SiC metalenses, which benchmarked high-performance commercial objective lenses and achieved diffraction-limited focusing. After a long period of high-power laser irradiation, the device performance remains stable and is almost unaffected by heat absorption. This achievement represents a major breakthrough in high-power laser systems, opening up new horizons for their application and efficiency improvement. The research results were published in the international journal Advanced Materials under the title of "4H-SiC Metalens: Mitigating Thermal Drift Effect in High-Power Laser Irradiation".

Thermal management is one of the important factors to ensure the stability of semiconductor lasers. In this paper, the heat transfer process of semiconductor lasers is analyzed, and the heat dissipation methods of high-power semiconductor lasers are summarized, hoping to provide some help to researchers engaged in high-power semiconductor lasers in the future.

We will delve into the teardown of the 5mW green laser pointer. Laser pointers have become ubiquitous in our modern world, serving a variety of uses from presentations to astronomy. But have you ever wondered about the internal mechanism by which these devices emit focused beams? Let's explore the teardown process and uncover the secrets hidden within.

For those who need to go on stage for a wonderful PPT explanation or teaching, in order to let the audience clearly grasp the progress position of what the narrator said, the guidance of the laser pointer is indispensable. However, there are not only a variety of styles that compound the functions of the briefing machine and mouse in the laser pointer products, but also common red light and professional-grade green light and blue light in terms of light color, so it must not be easy to buy. In this article, I will share how to buy a laser pointer.

The introduction of high-wattage 365 nm laser pointers has had a significant impact on various industries, from UV curing to forensic analysis, fluorescence research to entertainment. The power and precision of these lasers are revolutionizing existing practices and opening up new avenues for research and creativity. However, it is important to recognize the potential risks associated with UV wavelengths and prioritize the safety of their use. With the advancement of technology, the applications and advantages of 365nm high wattage laser pointers are bound to continue to expand, propelling us towards a brighter future.

The 301 500MW green high power laser pointer provides a powerful and versatile tool for a wide range of applications. Its high output power and superior range make it ideal for educators, astronomers, outdoor enthusiasts, and professionals. However, this laser pointer must be handled responsibly and the necessary safety precautions must be followed to prevent accidents and protect your own well-being and the well-being of others.

GaAs-based 980nm semiconductor lasers have important applications in materials processing, communications, and medical fields. The emergence of strain-variable subwell structures improves the conversion efficiency, output power and reliability of GaAs-based semiconductor lasers. In this paper, the historical development of high-power GaAs-based quantum well lasers is reviewed, the epitaxial structure, chip structure and packaging structure design of high-power semiconductor lasers are introduced, and the problems affecting the optoelectronic performance, heat dissipation and practical application of high-power GaAs-based quantum well lasers are emphatically expounded. In view of the above problems, the corresponding solutions and research results are discussed, and the shortcomings and improvement directions of each scheme are pointed out. Finally, the development status of high-power semiconductor lasers is summarized, and the development direction of high-power semiconductor lasers is prospected.

Laser pointer, also known as laser pointer, pointer, etc., is a pen-shaped emitter designed to be portable, easy to hold in the hand, and processed into a laser module (diode). Common laser pointers include red (650-660nm), green (532nm), blue (445-450nm), and blue-violet (405nm). It is usually used by newspapers, teachers, and docents to project a point of light or a ray of light directed at an object.

Beam synthesis is an effective technical solution to break through the power output limit of single-fiber laser and obtain higher power laser output. In recent years, breakthroughs have been made in various types of beam synthesis, such as power synthesis, spectral synthesis, and coherent synthesis, and the output power has been increased by an order of magnitude compared with the highest power value of a single fiber. Composite applications with multiple beam synthesis types are expected to further increase laser power, compress laser pulse duration, and achieve higher performance laser systems. Therefore, the latest research progress of high-power fiber laser beam synthesis is analyzed, the research trends are refined, the research characteristics are summarized, and the challenges and key technologies faced by the research and development of more types of beam synthesis systems in the future are analyzed and prospected.

The development history of high-power solid-state laser technology is a history of struggle with "waste heat", in order to suppress the adverse effects of thermal effect on beam quality, heat capacity lasers, thin slice lasers, slat lasers and fiber lasers have appeared successively, and the new gain medium form combined with advanced heat dissipation technology will increase the laser output power to the order of 100 kilowatts. The thermal performance of the solid-state laser gain medium is an important bottleneck that limits the further breakthrough of laser power. Therefore, it is of great significance to find laser crystal materials with ultra-high thermal conductivity. In this paper, the basic principles of the above four lasers and their research progress in high-power lasers are introduced
From the perspective of improving the thermal conductivity of gain dielectric materials, the existing methods and research results are analyzed and summarized, and the research on superthermal conductivity laser crystals and the development of high-power laser technology are prospected.

The laser pointer can damage the camera sensor, and its effects are related to the laser intensity and the duration of the irradiation. A normal laser pointer will not cause much damage if exposed to it for a short period of time, but a high-power laser pointer may damage the camera. The design and material of the camera affect its ability to resist lasers. Avoid illuminating the camera when using the laser pointer, and take precautions to reduce the risk of damage.

Beam quality factor is the main parameter to characterize the transverse pattern of high-power lasers, and in order to solve the problem that the current beam quality analyzer can only be used for beam quality evaluation of small-aperture and low-power lasers, the principle and simulation of attenuation and beam reduction technology for beam quality measurement of high-power lasers were studied. The simulation model of the attenuation and shrinking beam component is established, and the thermally induced aberrations of optical components under high-power laser are studied by using the finite element method, and it is concluded that when the peak-to-trough (PV) value of thermally induced aberrations is less than 82 nm, the influence on the beam quality factor is less than 5%. As the beam passes through the attenuation component, if debias occurs, the beam quality factor will be smaller. Based on the Zenic polynomial and the beam quality factor calculation model, the influence of the wavefront distortion of the beam shrinking component on the measurement is studied and analyzed, and it is seen through the Zemax simulation analysis that the influence on the beam quality factor measurement is less than 5% when the angle of view between the incident light and the center optical axis of the beam shrinking component is less than 7° during the assembly and adjustment.

The problem of heat dissipation with high heat flux density has become one of the key technologies for the development of high-power lasers. Based on our research work in recent years, this paper reviews the current research status of high-power laser cooling technologies that are currently being applied or studied, mainly including microchannel liquid convective heat transfer, solid cooling, spray cooling and micro heat pipe cooling. Then, according to the development trend of technology, microchannel boiling heat exchange cooling and liquid nitrogen cooling are two cooling technologies with good application prospects, and the current basic research progress of these two technologies is introduced.

A new multi-cavity structure is used to optimize the light field distribution of the vertical cavity surface-emitting laser (VCSEL), which solves the problems of low output power and poor beam quality caused by the severe carrier aggregation effect of large aperture devices. The results show that the new structure VCSEL has a lower threshold current than the traditional structure devices with the same aperture structure, especially the output power is increased by nearly 56% compared with the traditional structure, and the far field shows a Gaussian distribution. The research work provides a new technical approach for the realization of high-beam quality and high-power vertical cavity surface-emitting lasers.

The achievements of the research and development of high-power solid-state laser devices over the past decades and the traction of future needs, a generation of high-power solid-state laser technology has become history; The second-generation high-power laser technology is thriving and has become the mainstream technology approach; Three generations of high-power laser technology have emerged and shown strong vitality.

Key words lasers; high-power narrow-linewidth continuous-wave fiber laser; spectral broadening; phase modulation; stimulated Brillouin scattering effect

The purpose of the invention is to overcome the limitations of the above-mentioned existing inhibition of the thermal effect of high-power lasers, and to provide a compensation method for the thermal lensing effect of high-power lasers, which can effectively suppress the thermal lensing effect of high-power lasers, which is not only simple to operate, scientific and effective, but also has strong practicability.

Laser is another major invention of mankind since the 20th century, after atomic energy, electronic computers, and semiconductors. Semiconductor laser science and technology takes semiconductor laser devices as the core, covering the study of the law, generation method, device technology, control means and application technology of stimulated radiation amplification of light, and the required knowledge integrates geometric optics, physical optics, semiconductor electronics, thermodynamics and other disciplines.

After more than 50 years of development, semiconductor laser, as a world-class research direction, has developed by leaps and bounds along with international scientific and technological progress, and has also benefited from breakthroughs in various related technologies, materials and processes. The progress of semiconductor laser has received great attention and attention in the international scope, not only in the field of basic science and continuous research and deepening, the level of science and technology continues to improve, but also in the field of application continues to expand and innovate, the application of technology and equipment emerge in an endless stream, the application level has also been greatly improved, in the national economic development of all countries in the world, especially in the fields of information, industry, medical and national defense has been an important application.

At present, the development of semiconductor lasers in the world is in a new stage of rapid development, and China's laser science and technology has basically maintained a trend of synchronous development with the world. From the perspective of comprehensive social development, industrial economic upgrading, national defense and security application and economic structure transformation, from the perspective of national competitive development, more clear needs are put forward for the comprehensive innovation of semiconductor laser technology and the transformation and development of industrial applications. In this paper, the development history and current situation of semiconductor lasers are reviewed, and the achievements of Changchun Institute of Optics, Fine Mechanics and Physics in recent years in high-power semiconductor lasers, especially in high-power semiconductor laser laser light sources, vertical cavity surface-emitting lasers and new laser chips.