Month: September 2025

Micro-comb laser systems as variable microwave devices

Importance of low-noise signals

Low-noise signals play a crucial role in various applications, for instance, high-speed telecommunication and ultrafast data processing. Usually, huge and sensitive microwave oscillators emit these signals; however, these systems can not be applied outdoors. The promising solution is the application of high-quality pulsed laser systems based on micro-comb technology.

Advantages of micro-comb fiber lasers

This type of fiber lasers offers the high optical frequency and spectral purity of laser beam fields; they produce low-noise microwaves compactly and efficiently. These laser systems emit microwaves with limited frequency adjustment, which is why conventional resonator has to be huge and have difficulties in tunability.

Novel micro-comb laser technology

A team of scientists from Dublin presented a novel fiber laser technology for producing different low-noise microwaves with a single system. According to this technology, a microresonator frequency comb is installed into a compact laser system, whose “intensity is modulated by an off-the-shelf microwave oscillator.”

Tunable microwave generation

It is possible to emit new laser beam microwaves with tuned frequencies by forcing the modulation frequency to tightly follow a subharmonic frequency of the microwave. These microwaves provide lower phase noise than fiber laser systems used previously for the same purposes.

Frequency division and spectral purity

This fiber laser technology has a frequency division that allows for delivering the frequency purity of an optical signal into the microwave domain. It is possible to deliver the spectral purity between various microwave signals. Although it is challenging to perform ideal laser beam microwave frequency division in a tunable way, the fast-modulated fiber laser allows for making it by employing cost cost-effective photodetector and a moderate control system.

Spectroscopic applications and system components

This laser system produces a secondary frequency comb with more densified spectral emissions, leading to numerous spectroscopic applications. Additionally, the main elements of the system, for example, the microresonator and the semiconductor laser system, are considered to be discrete and connected with lengthy optical fibers.

Integration and miniaturization

The team now continues working on integrating and advanced-packing the system. The opportunity to make the device smaller and its mass production leads to a revolution in the market for portable, low-noise microwave and frequency comb tools.

Ultrafast coherently combined fiber laser technology

Introduction to ultrafast fiber laser technology

A team of researchers succeeded in developing the new ultrafast fiber laser technology due to coherent laser beam combination with direct water cooling. The laser system produces an average power that is 10 times higher than that of current high-powered fiber lasers, combining the output of 12 amplifiers.

Overcoming waste heat challenges

This combination allows for fiber laser systems to overcome any challenges presented by the waste heat that they create when emitting laser beam light. Current lasers’ parameters enable them to effectively dissipate waste heat (in the range of a single kW), but the exit beyond that range of power leads to a decrease in laser beam quality.

Performance and specifications

The new fiber laser system emits 10.4 kW average power at 80 MHz repetition, without any decrease in laser beam quality. The operating principle is based on the laser system that “is turned on and optimized channel-by-channel, with each channel performing at maximum pump power.”

Efficiency and pulse characteristics

Additionally, the fiber laser has already been tested and demonstrated 96% combined efficiency with a laser beam pulse energy of 130 μJ and a pulse duration of 250 fs. Thus, the problem of high noise has been overcome in the early stage due to direct water cooling, resulting in a highly reliable laser system.

Development stage considerations

In the development stage, the fiber laser demonstrated excellent performance at low average laser beam power for deactivated water cooling. When the cooling is activated, the level of noise increases and requires the cooling system. The amplifier layout has been changed, leading to solving the existing problem.

Beam quality and coherent combination

The researchers claim that the new fiber laser technology makes the system close to ideal laser beam quality, which is considered to be equal to 1. It is important because the aim of the development is the solution to solve the heat-induced problem of laser beam quality of individual amplifiers.

Advantages of coherent beam combination

The coherent beam combination makes it possible to unite several high-powered laser beams into one, and the power and beam quality remain the same while increasing brightness. This fiber laser can be used in extreme applications, for example, laser-driven particle acceleration and space debris removal. This laser system is ideal in industrial and manufacturing industries, for instance, in high-speed scanning and ablation cooling.

Finally, the fiber laser system has a sealed housing that prevents it from dust contamination during the operational process.

A thinner fiber laser scalpel

Introduction to the fiber laser scalpel

A team of researchers from Taiwan and Russia presented a new scalpel based on fiber laser technology. The fiber laser scalpel is twice as thin as conventional ones. Taking into account the fact that standard medical scalpels have different shapes for specific tasks, the new laser system provides numerous benefits.

Benefits of decreased thickness

The researchers have developed a scalpel based on a fiber laser system that allows for decreasing its thickness by half. The researchers claim that the created curvilinear shape opens numerous opportunities for fiber laser applications in medical fields.

Design and innovation in the laser scalpel

The team from Taiwan and Russia produces a laser beam “blade” applied in a medical scalpel with a given curved shape employing a photonic “hook”. There are laser beam scalpels only with an axisymmetric focus area, that is, their blade is cylindrical.

New blade shapes for medical applications

Another blade shape enables the researcher to open new applications of the laser system in medicine. This fiber laser scalpel is two times thinner than the cylindrical shape. Therefore, specific tasks require various shapes of standard surgical scalpels.

Operating principle of the fiber laser scalpel

It is possible to cut or remove tissue with a scalpel based on fiber laser technology. The operating principle is based on the laser beam with increased temperature in a limited range up to 400°С. Thus, the fiber laser system burns out the beam, while tiny blood vessels along the cut edges are sealed.

Advantages of the curved laser beam

The fiber laser scalpel provides incredible advantages; for example, the incisions made by it are pretty thin, and the radiation is not dangerous. The researchers have succeeded in bending the laser beam by the installation of an amplitude or phase mask at the end of the optical fiber.

Role of the optical mask

The mask in the fiber laser system is regarded as a small plate made of metal or dielectric material, for example, glass. The laser beam energy inside the optical fiber is redistributed by the mask, leading to a curved part of radiation localization at the end of the fiber (the so-called photonic hook).

Testing and results

The fiber laser system has already been tested and demonstrated that the curved blade has a length of up to 3mm. The thickness of the laser beam blade reaches 500 microns (slightly bigger than the diameter of a human hair). Test results make the fiber laser scalpel perfect for surgeries.

Laser beams control nanomotors

Expanding applications of fiber laser technology

Laser systems become an integral part of human life; fiber laser technology continues to develop, leading to the appearance of new applications and expanding the old ones. For instance, a team of scientists from Japan has presented novel linear nanomotors that can be moved in controlled directions by applying a laser beam.

Role in microfluidics and lab-on-a-chip systems

These fiber lasers used in nanomotors make it possible to develop new microfluidics and lab-on-a-chip systems with optically actuated pumps and valves or other devices based on fiber laser technology that can be previously challenging or even impossible to perform.

Challenges of nanoscale devices

Nanoscale devices greatly differ from the ones involving the contraptions that researchers have used to employed. For example, it is more challenging to produce and accurately control a nanomotor (the tiny motor that is smaller than a bacterium) based on the laser system than to drive a car.

Development of gold nanorod-based motors

The recent development of the Japanese team includes a fiber laser system used in linear motors made from gold nanorods that allow for moving in a controlled direction when subjected to a laser beam. The operating principle is similar to a sailboat that can be directed in any desired position.

Principles of nanomotor operation

Such nanomotors’ operation does not lead to following the direction of the laser beam. Their operation is based on the orientation, even when they are subjected to a laser beam emitting from another angle. Thus, the laser system moves due to the lateral optical force produced by the sideways scattering of the laser beam from the particles.

Advantages of the new fiber laser system

There is no need to direct or shape the laser beam with lenses, which was quite challenging previously. Compared to previous systems, the wavelength of light produced by the fiber laser does not influence or limit the size of new nanomotors.

Key role of plasmon resonance

The laser beam or the field gradient does not define the motion and does not restrain it; the direction is based on the orientation of the nanoparticles themselves. “The key to this fiber laser technology is the localized surface plasmon resonance – collective oscillations of free electrons – within periodic arrays of nanorods.” They emit a scattered laser beam in a particular direction.

Future applications of nanomotors

The team of scientists plans to apply this fiber laser system to develop a new platform for nano-sized devices with moving parts that follow predetermined paths while being directed by unfocused laser beams. Thus, they claim the cost and complexity of such systems can be significantly reduced while accuracy and robustness will increase.

Overcoming the limit of fiber lasers

The challenge of coherence in fiber lasers

According to a team of researchers from Australia, the coherence of laser systems can be significantly improved by overcoming limitations that have been considered to be fundamental for 60 years. Fiber lasers produce highly directional, monochromatic, coherent laser beam light.

Importance of coherence

The light is produced by the laser system as a narrow laser beam in a specific direction. The wavelength and phase of every photon are equal. The coherence of a laser beam, in turn, is regarded as “the number of photons that can be emitted in this manner, which is a property crucial in determining the performance of a fiber laser in precision tasks like quantum computing.”

Historical quantum limits

A quantum limit of laser beam coherence is not a new phenomenon, and it was discovered in the 1960s. There is a theory that the coherence of the fiber laser system is less than the square of the number of photons. The researchers suggest a way to apply laser beam energy to the system and how it is released to create the beam.

Role of quantum mechanics

Even though these suggestions are suitable for most standard laser systems, they are not obligatory when it comes to quantum mechanics. The ability of researchers to develop and control quantum systems has transformed the conception of what is practical. Numerous studies allow for a better understanding of quantum processes occurring in fiber lasers.

Novel approach to overcome coherence limits

The team of researchers from Australia has applied numerical simulations to show that it is possible to overcome the limitations of fiber laser systems. The fiber laser technology has already been tested and demonstrated that the laser beam coherence is less than the fourth power of the number of photons.

Higher photon storage and quantum models

When the stored number of photons in the fiber laser is large, as is generally the case, the upper limit is much higher than before. Also, the researchers have developed a quantum mechanical model for a fiber laser system that could reach this upper limit for coherence in theory.

Future applications of quantum-limited fiber lasers

Much time is required to create a super laser system. However, this fiber laser technology proves that the production of a quantum-limited fiber laser is possible by employing the superconducting technique. This kind of technology is also applied in the modern best quantum computers.
The developed fiber laser may have applications in that field. Thus, new fiber laser systems allow for expanding new applications and promoting new research into more energy-efficient laser systems.

Fiber laser technology for Mid-IR pulsing

Development of mid-infrared pulsed fiber lasers

A team of scientists from Austria has developed a new fiber laser technology that helps to expand the practicality and usability of the mid-infrared pulsed lasing process. Infrared laser systems are capable of producing brief and powerful laser beam pulses, and they are beneficial for molecular detection despite challenges in their earlier manufacturing. The scientists claim that these fiber lasers do not need a large experimental facility, and it is possible to decrease their size.

Role of quantum cascade laser systems

The first laser beam in the mid-IR range has been produced by a specially made quantum cascade laser system. Specific laser beam light wavelengths are dependent on the material’s atoms. Quantum cascade laser systems allow for creating and directing nanostructures to tune the laser beam light wavelength.

Frequency comb and vibration modes

This fiber laser allows for the generation of not only a single light color but also a variety of different wavelength frequencies. The laser system has a frequency comb because the spectrum is regular and the distance between frequencies is equal, like in a comb. Additionally, a phase of a laser beam plays an important role. The fiber laser system can have different vibration modes, with parallel, opposite motion resulting in different wavelength frequencies.

Sync and staggered vibrations

Laser beam waves can vibrate in sync and “then superimpose one another and generate short, intense laser pulses.” Their vibrations can be staggered when it comes to continuous intensity. Previously, the switching back and forth between these two options in a quantum cascade laser system has been quite challenging. Today, the fiber laser system includes a small modulator, through which the laser beam waves pass by again and again.

Function of the modulator

The modulator used in the new laser system has an alternating electrical voltage, which is the reason why it can emit various light vibrations based on the voltage frequency and strength. For instance, the manipulation of the modulator at the right frequency leads to synchronous vibration of various laser beam frequencies of the frequency comb. So it is real for the fiber laser system to unite these laser beam frequencies into short, intense pulses.

Applications and benefits of Mid-IR fiber lasers

The fiber laser technology is regarded as very promising because it allows changing the size of the system, therefore, resulting in novel applications. This type of laser system can be used in medical or scientific applications to design tiny measuring tools that apply specific laser beams to look for particular molecules. The benefit of high laser beam intensity advances measurements that need two photons at the same time.

Nonlinear laser beams in spatial systems

Novel approach to high-energy ultrashort pulses

A team of Swiss researchers successfully generated high-energy ultrashort pulses with single-mode beam quality by applying nonlinear beam cleaning within a multimode laser cavity. Previously, mode-locked fiber lasers with single-mode optical fibers were thought to support only temporal modes.

Advantages and drawbacks of single-mode fiber lasers

Mode-locked single-mode fiber laser systems are considered to be very advantageous. The benefits include high-gain doping, intrinsically single-spatial mode, and compact setups. High-power mode-locked fiber lasers have some disadvantages, such as high nonlinearity because of the compact core size of optical fibers.

Nonlinear beam cleaning in multimode laser systems

A team of researchers from Switzerland presented a novel technique for producing high-energy, ultrashort pulses with single-mode laser beam quality. They develop nonlinear laser beam cleaning in a multimode laser system cavity. The conventional technique generates low-power ultrashort laser oscillators to solve the problem.

Benefits of multimode optical fibers

Then it is necessary to increase the laser beam power levels by several amplifiers, but the process of external amplification makes the cost and complexity higher. Researchers prefer applying multimode optical fibers (graded-index) in fiber laser systems because of their low modal dispersion and periodic self-focusing of the light inside.

Spatiotemporal mode-locking technique

The researchers claim that it is possible to perform spatial laser beam cleaning, wavelength conversion, and spatiotemporal mode-locking using graded-index multimode optical fibers. The spatiotemporal technique mode-locking is a relatively new one that allows for creating ultrashort pulses by fiber lasers.
The technique produces “a balance between spatial and temporal effects within a multimode laser system cavity, which supports multiple paths to guide light.” A big multimode core leads to a decrease in the cavity nonlinearity; the fiber laser can achieve high pulse energy without external amplification. High-power mode-locked fiber laser systems suffer from a low-quality output laser beam because of multimode fibers.

Results and practical applications

Finally, the researchers tested the developed fiber laser technology and it demonstrated nonlinear beam cleaning in a multimode laser for the first time. The nonlinear laser beam cleaning promotes the creation of high-energy, ultrashort pulses with single-mode beam quality. The fiber laser technology directs a high-quality laser beam when mode-locking is reached.

Nanoparticle fiber lasers with low tissue damage

Development of a microcavity fiber laser

A team of scientists from Australia developed a microcavity laser system that emits energy-saving and user-safe laser beams with low pump power. This fiber laser technology has an excellent potential for nanoscale applications, especially in biology and medicine.

Challenges of nanosized fiber lasers

It is necessary to look deep inside tissue for biosensing and bioimaging research at the intracellular level. This is the reason why nanosized fiber laser systems have several challenges for these biological applications. These fiber lasers allow for directing the luminescent emitters included in individual nanoparticles to interact with one another.

Operating principle of nanoparticle fiber lasers

Electrons are accumulated at particular energy levels, and laser systems help to overcome the limits of the generally low pump laser beam power’s insufficiency in producing nanoparticles able to lase. These nanoparticles of the new fiber laser system will emit laser beams at pretty low pump powers.

Experimental validation

The fiber laser technology has already been tested by the researchers and showed a two orders of magnitude lower pumping threshold compared to that generally accessible. The operating principle of the laser system is based on the binding surface of the nanoparticle matrix to create a cavity surface with a uniform single layer.

Applications in biosensing and bioimaging

The researchers claim that it is possible to include the NIR microcavity fiber laser in thick tissues and single cells. Thus, the fiber laser system helps to detect environmental indicators such as temperature, pH, and refractive index. These factors play a crucial role because their change demonstrates the health status of the tissues or cells, leading to the opportunity of early-stage disease detection.

Potential for medical applications

Fiber laser technology is very promising for biological applications. The researchers could point a nanoparticle fiber laser “inside a cell and illuminate an area of interest inside the compartments of a cell.” Additionally, the opportunity to reduce pump power results in low tissue damage as the laser system penetrates the sample.

Accuracy and limitations

A narrow laser beam allows for more accurate detection. Nevertheless, interference greatly influences fluorescence-based sensing. According to test results, a single nanoparticle can operate like a fiber laser at low power with a sharp laser beam signal.

Fiber laser systems with an oscillating head

Application of fiber lasers in welding

The application of laser systems is widespread when it comes to the welding process. Specialists claim that fiber lasers will soon replace traditional welding technologies. The diode-pumped fiber laser systems are most popular due to their low cost, including the ongoing cost of maintenance, spare parts, and being environmentally friendly.

Continuous-wave lasers and beam focusing

Continuous-wave laser systems enable the transmission of uninterrupted laser beam lights that are highly valued in welding. The combination of a fiber laser with the right optics makes the size of the laser beam more focused, for example, a 51μm diameter spot that is 10 times smaller than that of a pulsed laser system.

Advantages of oscillating head technology

Fiber laser systems with an oscillating head provide better welds by applying mirrors that can handle high-power laser beams of 1.5kW. The benefits of lasers with an oscillating head help to achieve high power density that can melt most metal materials and even vaporize them if needed.

Welding types and related issues

There are two types of welds: conduction-limited and keyhole welding. Additionally, the molten pool interacts with the beam of the fiber laser, resulting in inefficient welds when left uncontrolled. The problem appears in deep and narrow keyhole welding, as well as in small welds.

Plasma formation and its influence

Plasma formation also influences the laser beam and leads to scattering effects that degrade welds. The solution to the problem requires the opinions of specialists. Effects such as thermal lens focusing or reflection focusing on the molten pool can lead to a temperature increase in the laser system.

Flexibility and precision of fiber laser technology

“When a gas is heated to a high temperature, it can be ionized and turn into a plasma, where metal vapor and dust can be aggregated, which generates a ‘plasma ball’ scattering the incoming laser beam in multiple directions.” It also decreases the quality of the fiber laser system.
Finally, fiber laser technology is considered to be very flexible compared to fixed fiber optics. It allows for controlling weld depth and width independently. It needs careful attention to such parameters as power, amplitude, frequency, and average speed. Low heat distortion plays a crucial role in laser systems.

Laser systems for surgical operations

Laser systems for surgical operations

Comparison of laser systems in urology

Researchers from the United States, Germany, and Switzerland have presented a comparison of the properties of two types of laser systems applied in urological procedures. The researchers have determined in which cases it is necessary to use each of them and which settings allow for achieving the best result.

Benefits of laser systems in surgery

Laser systems have been used in surgery for more than half a century, and nowadays they are used in urology, for example, during operations for bladder cancer, benign prostatic hyperplasia, and urothelial carcinoma. Laser systems offer several benefits over conventional surgical devices – their application reduces the cases of bleeding and the risk of complications, allowing surgery to be performed minimally invasive (with minimal damage to healthy tissue).

Characteristics of different laser systems

Laser systems are different from each other. The suitability of laser beams for specific types of operations is determined by their wavelength, duration, and strength of the pulse. They choose the degree of absorption and scattering of radiation, which means the speed and depth of dissection, the degree of damage to neighboring tissues, coagulation (irreversible changes in the structure of the protein), and carbonation. Different types of laser systems are suitable for various tasks; however, in recent years Ho:YAG has become popular, ideal for a wide range of operations, due to the high degree of laser beam absorption and pulsed exposure mode.

Development of the thulium fiber laser

Several years ago, specialists jointly developed and studied a new thulium fiber laser. Its laser beam emission is effectively absorbed in the water, which allows for increasing the speed of the operation. At the same time, the pulses of the fiber laser system reach lower peak power, gently dissecting the tissue, rather than tearing it, and they can operate longer, which gives a more uniform distribution of energy and less damage to the tissue.

Modes of operation: Ho:YAG vs. fiber laser

At the same time, Ho:YAG and fiber lasers have already been tested during the operation in two modes: quasi-continuous (a sequence of short pulses of equal power) and super-pulse. Each laser system was tested with different laser beam power settings and different speeds. In each case, the depth of dissection, the depth of coagulation, and the degree of carbonation were evaluated.
The fiber laser system allows deeper dissection of the tissue in a quasi-continuous mode, while the laser effectively coagulates the tissue. The fiber laser system in a quasi-continuous mode makes it possible to effectively dissect tissue and coagulate bleeding vessels, although the degree of tissue carbonization is higher.

The role of fiber lasers in modern surgery

Fiber lasers are one of the biggest and most significant changes in laser surgery in the last 20 years. The capabilities of these devices are actively studied all over the world, and their flexibility allows them to be used in all areas of urology.