Category: Fiber Laser Technology

Advantages of fiber laser weapons

Military weapons based on fiber laser technology are considered to be agile; they have virtually infinite ammunition, enabling them to take down different targets. Nonetheless, as fiber technology transforms, so do modern military actions also change, requiring advanced fiber laser weapons for everyday defense. Drones present a prominent security threat to military objects all around the world. Fiber laser weapons are regarded as a low-cost, powerful solution for militaries. The fiber laser technology offers such advantages as high precision, incredible flexibility, reusability, and it also allows minimizing collateral damage because the laser system weapons take out just the required target.

Operating principle of fiber laser weapons

The operating principle of modern fiber laser weapons is based on decades of research. These laser systems operate on batteries utilizing a technology called a spectral beam combined fiber laser. This tiny, powerful laser beam system applies artificial intelligence algorithms to stream fiber lasers into one larger laser beam.

Energy distribution and environmental resistance

The energy in the laser system weapons spreads by mirrors and lenses, which enable adjustments based on weather or atmospheric conditions. Additionally, the fiber laser weapons are not exposed to gravity or wind resistance. Militaries “can take out engines, instantly burn tires, sink a boat or bring down drones in a fraction of a second” with weapons based on fiber laser technology due to significantly focused energy laser beams.

Efficiency and logistical advantages

Additionally, it is unnecessary to launch a new projectile; when adjusting aim, simply repositioning the fiber laser suffices. The benefits of laser weapon systems as a munitions solution include that troops do not carry large quantities of ammunition, but instead only one weapon system. There is no need to transport hazardous munitions where mishaps may occur since the intense energy of laser beam weapons comes directly from generators or batteries.

Cost-effectiveness and mobility

Therefore, the lightweight of dangerous munitions also simply implies less cargo, resulting in less equipment and more stealthy troop movements. Standard missiles also have a high cost, while fiber laser weapons have almost infinitely renewable power, which is why the cost of the fiber laser system is offset by not needing to permanently buy munitions.

All the mentioned benefits of laser system weapons do not mean full replacement of conventional munitions; they only complement them. Nowadays, there are fully functioning fiber laser systems ready for field testing, and some capabilities have already been demonstrated.

Topological fiber lasers: a breakthrough

A team of researchers from Singapore designed the first electrically driven topological laser system. This fiber laser efficiently overcomes manufacturing imperfections due to the application of topologically protected photonic modes. In the 1980s, the researchers discovered that electrons flowing in certain materials had “topological” qualities; therefore, installed in fiber laser systems, they allowed electrons to flow around corners or defects without scattering or leaking.

This topological technique has been recently applied to photons by a team of researchers from Singapore. They used a quantum cascade fiber laser on advanced semiconductor wafers developed by the team. The team exploited a design that included a valley photonic crystal to reach topological states on a laser beam platform.

Design of the compact fiber laser system

The design of the compact fiber laser system contains “hexagonal holes arranged in a triangular lattice, etched into a semiconductor wafer. Within the microstructure, the topological states of light circulate within a triangular loop with a 1.2-mm circumference. The loop acts as an optical resonator to accumulate the light energy required to form a laser beam.” The laser beam travels in this loop and navigates the sharp angles of the triangle because of certain characteristics of topological states, whereas normal lightwaves are disrupted by the sharp angles, preventing them from circulating smoothly.

Electrically pumped THz quantum cascade fiber lasers

The quantum cascade fiber laser allows emitting a laser beam at terahertz (THz) frequencies. Although previous demonstrations needed an external laser beam source for optical pumping, now the developed fiber laser is based on an electrically pumped THz quantum cascade technology that uses topologically protected valley edge states; thus, the application includes the valley degree of freedom in photonic crystals. Electrically driven semiconductor laser systems are considered to be the most standard type of laser technology device at present and have a wide range of applications, from barcode readers to laser ranging sensors for autonomous vehicles.

The manufacture of fiber laser systems has numerous challenges, and modern laser module designs may not work well if any imperfections are introduced into the structure of the laser during manufacturing. The innovative topological laser system addresses the issue and may lead to more effective production using current laser technologies.

Recently, researchers from Massachusetts have developed a novel fiber laser system that has a compact size and is able to emit light with a high level of spectral purity. The fiber laser’s light remains unchanged in environmental conditions. The researchers confirm that the novel laser system will be useful for future scientific applications that include:

• clock improvement for Global Positioning Systems or GPS;
• determination of space gravitational waves;
• quantum computing.

Advantages of the fiber laser system

The fiber laser system has a lot of advantages, such as small size, the ability to emit exceptionally pure light, and unresponsiveness to the environment. Also, laser technology allows creating an environmentally stable, narrow, portable linewidth laser due to the fiber used for the laser module. A laser system is developed to emit purely in one wavelength, but there are still environmental influences that cause noise, changing the light frequency. The researchers using a novel technique have developed an optical fiber laser with a spectral linewidth narrower than ever achieved by a fiber or semiconductor laser.

Principle of operation

The main goal of the development is the replacement of ultra-low expansion (ULE) cavity lasers with a compact one that isn’t sensitive to environmental noise. The principle of laser module operation includes the use of a short loop of optical fiber configured as a ring resonator.

Performance and applications

Since fiber laser systems are portable and solid, and also have immunity to environmental changes, the researchers made the combination of fiber laser advantages with the nonlinear optical effect to develop a laser with a linewidth of just 20 hertz, compared to other laser systems, whose linewidths range from 1000 to 10,000 hertz, and semiconductor lasers’ linewidth is around 1 million hertz.
The development of laser systems can be used for the creation of a new generation of optical atomic clocks used for GPS-enabled devices. These clocks will provide a more accurate pinpoint of the arrival time of the signal and improve the location accuracy of today’s GPS systems.
This device will be quite useful for interferometers like the ones used by the Laser Interferometer Gravitational-wave Observatory or LIGO, to detect gravitational waves coming from colliding black holes or collapsing stars.

Ultrashort laser pulses and their challenges

The generation of ultrashort laser beam pulses needs careful monitoring of the light’s dispersion provided by a fiber laser. There is a dependency of phase velocity and frequency; a real laser beam pulse includes a spread in frequency, which will enlarge as it goes through an optical medium. Thus, simple, low-cost sources of sub-picosecond laser beam pulses, soliton fiber laser systems, including a laser diode and an optical fiber, are considered to become an ideal solution.

Balancing dispersion with Kerr focusing

This type of laser system allows decreasing the spread by “balancing it against Kerr focusing – the narrowing of a laser beam pulse caused when light’s electric field alters the medium’s refractive index – so each pulse travels as a soliton, and its duration remains unchanged.” Soliton fiber lasers are regarded as very promising because of such benefits as simple construction; they are not able to reach the high energies of techniques, for instance, chirped-pulse amplification.

Overcoming energy constraints with new technology

New fiber laser technology allows overcoming these limitations. The operating principle of the fiber laser is based on the application of a spatial light modulator to manage the light’s dispersion relation to enabling higher laser beam energy pulses. A dispersion relation demonstrates how a wave’s frequency is relevant to its wavelength. “For light in a conventional soliton laser, the function is approximately quadratic, and its second derivative describes how a laser beam pulse would spread in the absence of Kerr focusing.”

Role of higher-order dispersion

Researchers from Australia have demonstrated that higher-order dispersion provides real benefits. A photonic crystal waveguide based on fiber laser technology has been developed, where the effects of second- and third-order dispersion were suppressed due to the waveguide’s geometry. The balancing process of fourth-order dispersion with Kerr focusing is connected to soliton formation.

Programmable spatial light modulators

The soliton fiber laser system acts by applying the same principle. The researchers employed a programmable spatial light modulator instead of a specially designed waveguide to produce the required dispersion profile. Additionally, the researchers claim that the energy of the quartic laser beam pulses is regarded as proportional to τ−3, as predicted for fourth-order dispersion solitons.

Modern laser systems in microscopy

Modern laser systems in microscopy allow researchers to discover how molecules within a cell react and interact when it comes to investigating tumor growth. Laser beam microscopy requires to be labeled with fluorescent substances that make them visible to researchers; however, it may misrepresent the molecule behavior. New microscopes based on fiber laser technology operate without the need to label the molecules.

Design of the new fiber laser microscope

A team of researchers from Germany and China designed a microscope that includes a unique compact fiber laser instead of the solid-state laser systems that used to be applied. The microscope based on fiber laser technology produces less noise than conventional designs, allowing them to be used in operating rooms.

Advantages of fiber laser microscopy

Label-free microscopy in biomedical research

Usually, staining with fluorescent markers can not be performed on in vivo tissues; label-free microscopy plays a crucial role in understanding how different new types of cells develop from stem cells, as well as in differentiating a tumor from normal tissue without staining. Fiber lasers allow researchers to operate without markers in the muscle tissue cells of the heart and liver, as well as other cells.

Comparison with solid-state laser systems

Advanced fiber laser systems find their wide application in optical nanomicroscopes, in which laser beam light is transmitted through glass fibers rather than through a solid body of crystal or glass. Previously, solid-state laser systems surpassed fiber lasers because of their higher power and less noise. Researchers used two synchronized optical resonators (laser beam cavities), the wavelengths of which were required to hit the specimen through the lens at the same time, resulting in challenging control of the whole process.

Practical benefits of the new system

The developed fiber laser microscope presents an essential benefit that includes easier operation than a conventional solid-state laser system. This fiber laser system is less subject to error, and the process becomes faster because it does not need to label the molecules. The prototype of the fiber laser microscope promotes the development of portable devices that can be applied in the operating room, for example, to mark tumor borders during an operation.

Future applications in medicine

The new fiber laser technology provides benefits for numerous biomedical applications, and the early detection of tumors is only one specific example of this. It is planned to employ the new fiber laser microscope in clinical applications in the near future, because preliminary studies have already been conducted and demonstrated amazing results.

Role of fiber lasers in quantum technologies

Numerous quantum laser technologies imply the application of narrow-linewidth tunable diode lasers, amplified and frequency-doubled laser systems, frequency combs, and wavelength meters. Fiber lasers play a crucial role in quantum technologies. For instance, the laser systems are considered to be a product of the first quantum revolution, but their use is not limited to just optical quantum technologies. The fiber laser systems are widely utilized in numerous quantum setups.

Laser sources as the foundation for quantum networks

Laser beam light sources create the basis for quantum networks, i.e., “photons are regarded as the natural carriers of quantum states over long distances.” Laser systems are important in the production of such devices as quantum computers, quantum sensors, and optical clocks. Fiber laser technology offers total control over all degrees of freedom of the laser beam light, quite often at the quantum limit, resulting in an incredible way to start, manipulate, and read out various quantum tools. Laser systems provide such qualities as wavelength, linewidth, power, polarization, temporal, and spatial laser beam profiles. A single-frequency fiber laser system is not always suitable for several applications.

Applications in atom control and cooling

For example, two phase-locked laser systems allow operating transitions in atoms that a single fiber laser could not manage. The laser beams can be applied as optical traps in order to direct the movement of the atoms. One more application includes cooling atoms as far as the absolute ground state, required in total control over the spectral qualities.

Scaling quantum computers with fiber lasers

High-powered laser beams are essential when scaling quantum computers, where it is necessary to address each ion individually. Fiber laser systems are perfect in operation with optical amplifiers, for example, semiconductor-based tapered amplifiers, and the spectral qualities provided by laser technology enable them to inherit. “Starting from a single laser system that is tailored to offer the required, very specific spectral qualities, laser beam splitting and concatenation of tapered amplifiers provides the necessary scalability.”

Multiple laser systems in complex setups

It is not surprising that numerous setups are needed for several fiber laser systems (some a dozen of them), all with various properties, taking into account the relevance and versatility of lasers for quantum technologies. Certain applications of quantum computers require a few laser systems of the same type in one setup, increasing the total number to tens of lasers.

Introduction to industrial fiber laser technology

A team of scientists from the U.S. presented a new fiber laser technology that allows for industrial laser systems to emit attosecond laser beam pulses. Usually, attosecond science presents several difficulties because it is based on world-class fiber laser devices.

The opportunity to apply industrial laser systems instead of complex devices that need huge laboratory tools and cleanroom environments enlarges new possibilities, resulting in higher accessibility to researchers from all spheres. The generation of short laser beam pulses required for attosecond research needs the light to be directed through tubes filled with noble gases (xenon or argon) to compress them in time.

Nonlinear compression for attosecond pulses

The scientists claim that nonlinear compression performed by the fiber laser is considered to be efficient when driven in molecular gases, employing laser beam pulses substantially longer than a few cycles, because nonlinearity is increased. The fiber laser technology has already been tested, and the scientists have succeeded in compressing about 100-cycle laser beam pulses generated by an industrial fiber laser system by applying molecular gases – nitrous oxide in the tubes leading to a change in pulse length.

Molecular alignment and supercontinuum generation

These laser systems allow for simultaneously driving molecular alignment and supercontinuum generation in a gas-filled capillary. Pulses of single-cycle laser beams are considered feasible to produce with this fiber laser technology. Industrial laser systems that can be easily bought at an appropriately accessible price now are applied to emit attosecond pulses.

Importance of gas choice and pulse duration

The choice of gas and the durations of the laser beam pulses play a crucial role. For example, the use of molecular gas results in an enhanced effect. Therefore, the choice of gas is “important since the rotational alignment time depends on the inertia of the molecule, and to maximize the enhancement we want this to coincide with the duration of our pulses generated by the fiber laser.”

Prospects of attosecond fiber lasers

The development of fiber laser technology makes the system adjustment simpler, promoting the operation with a wide variety of laser systems with various parameters. The research of attosecond science is regarded as very promising because such fiber lasers make it possible to construct images of the electrons and study the fast motion of electrons inside atoms.

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.

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.

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.

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.

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.

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.