Category: Applications of Fiber Lasers

History and significance of laser technology

More than 40 years have passed since the development of the first laser system, but this was enough to make quantum electronics one of the leading areas of science and technology. Numerous improvements of lasers and their application make it possible to obtain fundamentally new results in information systems and communications, in biology and medicine, in space, and in other scientific research.

Unique properties of laser beam emission

Laser beam emission is characterized by monochromaticity, sharp focus, due to which it is possible to concentrate laser beam energy and power at considerable distances, the ability to vary the modes of radiation from continuous to pulsed with different pulse durations, and finally, coherence and polarization. A unique combination of these properties allows realizing various interaction mechanisms – both thermal (plasma formation, ablation, evaporation, melting, heating), and non-thermal (spectral resonance) effects on matter, which affect complex atomic and molecular systems.

Early adoption in medicine

It is not unexpected that the concept of employing laser beam radiation in medicine seems to be one of the initial. Over the past years, fiber laser devices and techniques have been used in almost all sections of medicine. Fiber lasers are especially successful in surgery, therapy, and the diagnosis of diseases. At the same time, it was discovered that each type of laser system operation, each laser-medical technique requires a specific combination of basic parameters of laser beam radiation and knowledge of the mechanisms of its interaction with various tissues.

Main areas of fiber laser application

Today, there are three main areas of fiber laser application in medicine.

Non-invasive diagnostics

New methods of non-invasive diagnostics: optical coherence tomography is considered to be a promising method for the diagnosis of ophthalmic and cancer diseases, and laser spectral analysis of biomarker molecules in exhaled air for diseases of the gastrointestinal tract. 

It is these diagnostics that use such unique properties of laser beam radiation as high coherence and polarization, which distinguish it from ordinary, even monochromatic, light.

Therapy using fiber laser systems

The therapy by fiber laser systems is widely used: irradiation with low-intensity laser systems of poorly healing wounds or human blood; in combination with photosensitizers, low-energy fiber lasers are used to selectively destroy cancer cells, atherosclerotic plaques, and treat macular degeneration (photodynamic therapy).

Surgical applications

Powerful (high-energy) laser systems are used as a surgical tool in ophthalmology, otorhinolaryngology, urology, and cosmetology. The surgery uses high-intensity laser systems that cause irreversible changes in tissues: welding, evaporation, and ablation (removal and cutting).

External and intravenous laser therapy

The therapy by fiber laser systems is another area that has become most widespread in the whole world – irradiation with low-energy lasers of blood and poorly healing wounds.

Mechanism of external laser therapy

For external use, laser system treatment occurs by exposure to certain areas and points of the body. The light penetrates through the tissues to a greater depth and stimulates the metabolism in the affected tissues, activates the healing and regeneration of wounds, and there is a general stimulation of the body as a whole.

Mechanism of intravenous laser therapy

During intravenous fiber laser system therapy, the laser beam influences the blood through a thin light guide that is inserted into a vein. The intravascular effect of low-intensity radiation allows you to affect the entire mass of blood. This leads to stimulation of hematopoiesis, strengthening immunity, increasing the transport function of blood, and also helps to increase metabolism. Significantly positive effects in laser system therapy of angina pectoris, myocardial infarction, and other pathologies were obtained with the introduction of an optical fiber through which laser beam radiation was introduced into the patient’s elbow vein.

Coherence and polarization considerations

Fiber laser radiation differs from ordinary, even monochromatic light by its coherence and polarization. There is a misconception that these special properties are responsible for the observed clinical and photobiological effects. As the laser beam penetrates deeper into the biological tissue (skin, organ, blood), coherence and polarization persist only to a depth of 200-300 microns, and then these properties disappear, and incoherent and non-polarized, monochromatic radiation spreads. Consequently, the beneficial effects observed during laser system therapy of various diseases are caused not by some special properties of fiber laser exposure, but are similar to the action of ordinary unpolarized and incoherent light with an appropriate radiation wavelength.

Secondary radiation and deeper effects

Photons emitted by electrons of excited biomolecules form secondary radiation that propagates (scatters) in all directions and excites other biological tissue molecules, increasing the depth of effective exposure. Due to the diversity of biomolecules in the body, secondary radiation is broadband, incoherent, and non-polarized.

Role of blood and lymph transport

Another factor that increases the depth of effective exposure is the transfer of excited molecules by blood and lymph throughout the body. It can be assumed that at depths exceeding 3 cm, the main biological effect is exerted not by the primary, laser beam radiation, but rather by the secondary scattered broadband incoherent and non-polarized radiation.

Challenges in dose determination

It is also very difficult to determine in practice the dose of absorbed laser beam radiation, since the proportion of reflected and absorbed radiation depends on many factors, so some researchers believe that fiber laser system therapy is an art like all medicine.

Mid-IR fiber laser applications

Today, two applications of fiber laser selective excitation of material vibrational levels in the mid-IR region of the spectrum are distinguished: fiber laser surgery of soft and hard tissues and laser system evaporation of polymers for thin-film spraying. These fiber laser system applications are based on the ability of mid-IR lasers to cause thermal or thermomechanical changes in the materials being processed, which can be classified as phase changes rather than laser beam chemistry. Fiber lasers have great potential for creating precision surgical instruments, due to their ability to focus laser beam radiation into a small spot along the length. A larger penetration depth increases the number of damaged cells, while a shorter depth results in less material removal per pulse.

Surgical precision and ablation

The goal of laser beam ablation is to remove a specific part of the tissue, leaving the surrounding tissue biologically alive. Surgical requirements, however, are often the opposite: high ablation rates are required in dentistry, while they should be minimal in refractive ophthalmology; cutting vascular tissues (brain surgery) requires some amount of surface coagulation (“thermal damage”) to achieve hemostasis (stop bleeding), while for non-vascular tissue (cosmetology) wound healing is better when there is no thermal damage.

Photodynamic therapy (PDT) with fiber lasers

Laser systems are finding new applications in PDT, a new cancer treatment method. Unsuccessful attempts to control the development of cancer remain a major problem. The main goal for patients with an incurable disease is to delay the development of the tumor. If the tumor is not large, the fiber laser system thermal ablation may become the treatment.

Mechanism and applications of PDT

Photodynamic therapy (PDT) by laser systems is another minimally invasive strategy for the removal of tumors. The idea behind PDT is to use the toxicity of porphyrin to destroy tumors. Up to the present moment, it has mainly been used to treat superficial, malignant, or pre-malignant lesions of the mucous membrane, carcinoma of the bladder, tumors of the esophagus or bronchus, a tumor on the head or neck, accessible through the endoscope. In combination with special catheters and the development of new photosensitizers, PDT by fiber laser systems can be effective for patients with solid tumors and especially with liver metastases.

Replacing traditional ultrasound imaging

Conventional ultrasound imaging has been substituted by a laser technology alternative that does not require physical contact and can be used on patients who cannot tolerate a probe on their skin, such as burn victims, individuals with sensitive skin, and infants. Tissue imaging has been conducted safely using a remote laser system aimed from half a meter. The laser technology was tested on the forearms of volunteers, resulting in high-quality images, comparable to the standard ultrasound, where common tissue features, such as muscle, fat, and bone, down to about 5 cm below the skin, were observable.

Challenges of laser-based imaging

Sound waves can penetrate further into the body than light; therefore, the primary challenge is converting a laser beam’s light into sound waves at the skin’s surface to visualize deeper within the body. 1550-nm lasers are used for tests because a laser beam wavelength is absorbed by water and is safe for the eye and skin with large safety margins.

Human skin consists largely of water, so researchers confirm that it should ideally absorb the wavelength of 1550-nm lasers and that it would heat up and expand in response. Then it is expected that the skin creates sound waves that spread through the body as the laser system’s wavelength returns to its standard state.

Dual-laser setup for imaging

One pulsed laser at 1550 nm that emits sound waves, and a second continuous laser system that remotely detects reflected sound waves, are used to test the idea. This second laser acts as a motion detector, allowing the measurement of vibrations at the skin surface. Skin surface motion, in its turn, changes the laser beam’s frequency. The 1550-nm laser system enables obtaining data at various points and creates an image of the region.

Testing and results

The first tests of the developed laser system include imaging of metal components installed in gelatin (similar to water in skin),  imaging of animal tissues, and then experiments in humans. Ultrasound scanning of forearms helps to develop the first fully non-contact laser system for safe tissue imaging. Additionally, the 1550-nm laser system allows a clear distinction of the fat, muscle, and tissue boundaries.

It is planned to improve the laser technology by increasing the laser system’s performance. Moreover, the researchers plan to update the detection laser beam’s abilities as well as to miniaturize the laser system setup up resulting in the manufacture of a portable imaging device that may be used at home.

Exploring the Moon’s south pole for water

The Moon always attracts people’s attention; it is fraught with many mysteries, which researchers try to reveal. There are craters in the south pole that have remained dark for billions of years; however, researchers claim that the region may include water. NASA encourages different research teams to create technologies to look for and extract water from these areas by using fiber laser technology.

Femtosats and laser technology

One group of researchers has proposed a technique based on the combination of laser beam power with femtosats (compact, disposable satellites) to look for water on Earth’s moon. “NASA selected eight university teams, including a joint team of researchers from the Colorado School of Mines and the University of Arizona, to develop fiber laser technology to support efforts to find and harvest water at the moon’s south pole.”

Laser-powered lunar exploration

Colorado School of Mines studies the concept of laser system application to power laser beam lights and machinery employed for lunar exploration. The researchers plan to apply femtosats, tiny satellites about the size of a stick of butter with laser systems, to verify the viability of using laser beam signals for power and communication in a lunar environment.

Advantages of compact satellites

The peculiarities of these compact satellites are that they are considered to have a low cost; therefore, it is possible to buy tens, hundreds, maybe even thousands for the price of one standard satellite. Insufficient research about the environment of the moon’s south pole led to the combination of the disposal spacecraft with a fiber laser is an ideal technique to examine these areas without risking hurt to a more expensive satellite.

Mission concept for lunar water search

The researchers proposed to conduct a mission in which is that a lander-mounted fiber laser system will land on the surface of the Moon and set the femtosats into action at various points on the lunar surface, applying a jack-in-the-box-like technique. The femtosatellites obtain the laser beam signal from the laser system and transmit it back to prove the validity of applying the fiber laser for communication.

Ultimately, the researchers are currently creating the complete fiber laser system, a task that is quite uncommon, especially in the aerospace sector. This mission is a step toward creating the required laser technologies to search for and extract water on the lunar surface.

Benefits of ultrafast fiber lasers

Ultrafast fiber laser systems provide two unique benefits that include the highest accuracy in material processing and the capability to process almost every material. Fiber lasers of average powers, up to approximately 100 W, are used for industrial applications, while laser systems of higher powers are more suitable for research.

Development of next-generation fiber lasers

Also, the popularity of fiber laser systems is growing. A team of researchers from Germany has developed the next generation of ultrafast laser systems with enough power to overcome standard lasers. Apart from the development of fiber lasers, it is planned to create process laser technology and the first applications as well.

Laser design and efficiency

The team consists of laser beam source development groups that work on complementary approaches to create a totally new fiber laser system. The new fiber laser is based on a decade-long experience with a special slab laser system design. The fiber laser is perfect for the generation of continuous-wave (CW) laser beam radiation efficiently with diode pumping.

High-power pulsed radiation

This laser system is considered to be a solution for the emission of pulsed and ultrashort-pulsed laser beam radiation. The present version is developed for 5 kW laser beam radiation with 800 fs pulses from two amplifier stages. The power radiation is planned to increase up to 10 kW by using a thin disk amplifier stage.

Coherent beam combination concept

The concept of a coherent combination of fiber laser beams has also been developed. According to the concept, “almost-identical fiber amplifiers are pumped by one seed laser system, and they then generate amplified laser beams in parallel. With optimal spatial and temporal overlap, these beams can be combined with 96% combining efficiency.” The fiber laser has already been tested and demonstrated 10.4 kW of compressed average power with 240 fs pulses.

Additionally, the researchers pay attention to process technology to promote the efficient application of such high powers, resulting in the development of high-speed polygon scanners that improve laser beam deflecting and splitting schemes. The process of splitting off a multikilowatt laser beam into arrays of more than 100 identical but shaped laser beamlets allows performing high-throughput micromachining.

Introduction to fiber laser material processing

Laser technology for material processing is currently experiencing the peak of its development and popularity. Modern fiber laser technologies are rapidly being introduced into industrial production and the advertising business, often replacing traditional methods of material processing.
The focused laser beam of adjustable power turned out to be an ideal “working tool” for the creators of new equipment. The laser system for cutting and marking, welding and surfacing, as a material processing tool, works quickly and does not wear out; it is economical, highly accurate, and its impact is easy to control and manage.

Advantages of fiber laser technologies

Laser  technologies for material processing have several advantages that contribute to the expansion of their application in various industries and services:

• a diverse selection of processed materials.
• no mechanical impact on the product with minimal thermal,
• precision and guaranteed repeatability,
• high contrast and durability of the images applied,
• high speed and performance, saving on consumables, and low power consumption,
• possibility of laser beam processing in hard-to-reach places, on flat and curved surfaces,
• the ability to integrate the fiber laser into various technological processes, including production lines and robotic systems.

Applications of fiber laser systems

Laser system engraving is effective for personalization of souvenirs and gifts, and fiber laser application for personal and greeting inscriptions. Laser beam cutting as a high-precision tool allows for the production of products with minimal material consumption and without additional processing of the cutting edges. Laser system welding is characterized by high welding speeds and high-quality welds with minimal weld sizes.

Laser hardening

A fiber laser or thermal hardening of metals and alloys by laser beam emission is based on local heating of a surface area under the influence of radiation and subsequent cooling of this surface area at a supercritical rate as a result of heat transfer to the inner layers of the metal.
In contrast to the known processes of thermal hardening by quenching with high-frequency currents, electric heating, melt quenching, and other methods, heating during laser beam hardening is not volumetric, but a surface process. At the same time, the heating time and cooling time are insignificant, and there is almost no exposure at the heating temperature. 
These conditions provide high rates of heating and cooling of the treated surface areas. Due to these features, the formation of the structure during laser beam heat treatment has its own specific features. The main purpose of fiber laser thermal hardening of steels, cast iron, and non-ferrous alloys is to increase the wear resistance of parts working under friction conditions. 
As a result of laser system hardening, high surface hardness, high dispersion of the structure, a decrease in the coefficient of friction, an increase in the bearing capacity of the surface layers, and other parameters are achieved. Fiber laser hardening provides the lowest wear and friction coefficient, and furnace quenching – the highest. 
Along with this, hardening by the fiber laser system is characterized by very small running time (only two or three cycles), a decrease in the upper values of the number of acoustic emission pulses, and a small interval of change in the number of laser beam pulses. This is due to an increase in the uniformity of the microstructure of the surface area after laser system hardening.
The wear resistance of cast iron and aluminum alloys under sliding friction conditions after continuous laser treatment is noticeably increased. The increased wear resistance of cast iron after laser beam treatment is due not only to the corresponding structural and phase composition but also to improved friction conditions. It also increases the wear resistance of steels and some other alloys when friction occurs in alkaline and acidic environments.

Laser system cutting

Fiber laser cutting is a laser technology that uses the energy of a laser beam to cut various materials. Laser cutting is usually used on industrial production lines. Technologically, this process is reduced to focusing a high-energy laser stream on the material being cut. The material, in turn, begins to melt, burn, evaporate, or be removed by a stream of auxiliary gas. 
The laser beam cut is characterized by high edge quality and positioning accuracy. Powerful industrial fiber lasers can cut metal sheets and other materials of various shapes with equal ease. Laser system cutting has a number of advantages over other metal-cutting methods. 
The advanced equipment of the fiber laser system cutting machine is able to process almost all metals and their alloys. It becomes possible to achieve a minimum area of the cut, while there is almost no deformation of the edges. The purchase of laser system cutting equipment is advisable in cases where it is necessary to perform the following types of work:

• Machine processing of metal without high initial costs and physical contact with the metal
• Metal processing without using a large amount of manual labor
• Metal cutting that does not involve further processing of the part
• High-speed metal cutting, which is accompanied by a slight thermal effect on the metal surface
• Cutting of finished products (past painting processes, etc.) without losing the external qualities of the part.

The fiber laser is able to operate in pulse-periodic and continuous modes. The technological capabilities of the laser beam equipment allow performing metal cutting operations that are accompanied by a small amount of waste. Since the laser system cutting machine is characterized by high positioning accuracy, it is possible to significantly reduce the cut tolerance, which leads to high economic efficiency of cutting. 
The laser beam of high quality makes it possible not only to cut metal with high precision but also to create holes in it with a diameter of 0.2 mm or more. The fiber laser system for cutting is characterized by a high speed of operation, which depends on the power of the laser beam.
Laser cutting equipment makes it possible to process non-rigid parts and parts that are easily subject to deformation. The use of laser technology enables cutting out details of any, even the most complex contour.

Laser engraving

Fiber laser engraving includes the removal of the surface layer of a material (metal, plastic, leather) or coating (paint, electroplating, spraying) under the influence of the laser beam of high quality. Laser system engraving will not be erased and will not fade. It can rightfully be called eternal. 
The laser beam process is controlled by a computer, which allows engraving images from any digital format (after the necessary processing). The laser beam of high quality allows applying high-resolution images. This makes it possible to engrave high-quality microimages and microtexts.
The laser beam modes embedded in the system can vary widely. This allows adjusting the depth of the burning of the material. For example, there is a deep engraving in metal for maximum clarity and durability, or evaporation of the top layer of paint for the product label without affecting the material itself.
In addition to the standard three-dimensional laser system engraving, there is a technology for obtaining color engraving. Colors in fiber laser engraving of metal are achieved due to the appearance of oxide films in the area of laser beam exposure. The laser technology for obtaining them is innovative and unique. The colors are selected separately for each new material.

Laser welding

Fiber laser welding is a welding technology used to attach various parts of metal using a laser system. Due to the high concentration of laser beam energy in the welding process, a small volume of molten metal, the small size of the heating spot, high rates of heating and cooling of the weld metal, and the near-weld zone are provided.
The process is often used to perform large volumes of production, such as in the automotive industry. Depending on the purpose, continuous or pulsed fiber laser operation can be used. A laser beam with a pulse time of the order of milliseconds is used for welding very thin workpieces. A continuous laser system is used for deep welding.
Fiber laser welding is a universal welding method that can be used to weld carbon steel, stainless steel, aluminum, and titanium. A high cooling rate can lead to thermal damage when welding carbon steels. The welding quality is high, similar to electron beam welding. The welding speed is proportional to the applied power and also depends on the type and thickness of the workpieces. 
The high power potential of fiber laser systems makes them particularly suitable for large production volumes. This type of welding is particularly dominant in the automated industry. Some of the advantages of fiber laser welding compared to conventional include: air route can be used to transmit the laser beam, that is, there is no need to vacuum, it is easy to synchronize manipulators, there is no X-ray radiation, and it provides the best quality of welds.
One of the methods of laser system welding is hybrid laser beam welding. This is a combination of laser and arc welding (gas metal arc welding). The electric arc melts the wire, ensuring a constant arc length, while the wire is fed automatically by the wire feeder. Protective gases (argon, helium, carbon dioxide, and their mixtures) are used to protect against the atmosphere that appears from the welding head, together with the electrode wire.

Overview of fiber laser welding

The fiber laser welding technology keeps expanding as a promising method with advancements in weld quality, dependability, and efficiency. Most fiber laser welding applications are regarded as autogenous, which means the weld is created entirely by melting parts of the base metal, and no additional filler wire or powder is applied.

Applications and need for filler material

Welding applications of a laser beam are almost always autogenous for a huge variety of materials. There are specific materials and challenging applications of laser systems that need the use of filler material in the welding process, resulting in great improvements.

Advantages of fiber laser welding with filler material

The improved fiber laser system provides better joint fit-up tolerance, avoiding solidification cracking during the welding process. The laser system welding changes the chemical composition or the microstructure of the weld metal to obtain suitable mechanical properties, as well as improves the weld profile.

Types of filler material

It is possible to use powder or wire filler material during laser beam welding. Most industrial laser system applications are based on wire use. The main reason for its use is regarded as low cost because generally, powder feedstock is more expensive than wire for most materials.

Factors affecting quality and process

Fiber laser welding with filler wire depends on several conditions that define quality, process speed, and cost. For instance, “the wire feed rate is dependent on welding speed, the cross-sectional area of the gap between the joint face and cross-sectional area of the filler wire.” The application of filler wire in a laser system usually leads to a 10-20% reduction in welding speed, for a given laser beam power, to compensate for the fiber laser energy that has to be used to melt the wire.

Laser beam and filler wire interaction

Laser beam-filler wire interaction also plays a crucial role. The short length of the wire interferes with the wire from being melted at the initial part of the bead; therefore, the laser beam directly leads to the material being melted. The long length of wire, in turn, causes the extended wire end to be pressed against the plate surface.

Importance of focused spot size

It is necessary to pay careful attention to the focused spot size: it should be close to the filler wire diameter because a small spot size of the fiber laser system compared to the wire diameter results in welds with porosity because the filler wire has not melted properly.

Applications and effectiveness

Finally, the fiber laser technology has been tested and demonstrated that fiber laser welding, applying filler wire, provides effective in producing high-quality, robust welds with improved fit-up, reduced weld cracking, and better weld profile. It is possible to use fiber laser systems in a wide range of applications, such as aerospace, automotive, and many industrial fabricating applications.

Innovative fiber laser technology in medicine

A company-manufacturer of medical devices presented innovative fiber laser technology that allows for decreasing treatment time and increasing procedural efficiency. The super pulsed laser system is based on the thulium fiber laser technology developed for stone lithotripsy and soft tissue applications.

Regulatory approval and initial testing

The presented laser system obtained the regulatory approval that enables the application of the fiber laser in the medical world globally. The fiber laser system has already been tested on synthetic kidney stones and demonstrated that this technology can dust stones in half the time it takes other systems, while also creating a fine dust that is easily removed.

Clinical advantages of the super pulsed fiber laser

The laser beam application in early cases leads to the system having practically no retropulsion at chosen settings, and the fiber laser provides accurate soft tissue cutting with visibly improved hemostasis capability. The super pulsed thulium fiber laser system changes the game rules in medicine.

Faster stone fragmentation and patient benefits

The laser system is considered to be faster; it dusts stones into tiny particles that more easily wash out during the procedure, which is a crucial advantage for patients. “When kidney stone fragments don’t clear during or after the lithotripsy procedure, they can potentially grow into bigger stones that lead to future stone-related events such as painful colic and the need for urgent intervention.”

Superior performance and a unique laser module

This fiber laser technology is regarded as highly promising and even superior in several features and performance metrics. The operating principle of the fiber laser is based on a laser module configuration unique within the medical area, providing the broadest range of settings available, containing very low energies and high laser beam frequencies that can transmit superior performance across a range of applications.

Optimized wavelength and energy absorption

The laser beam has energy emitted at 1940 nanometers (the optimal wavelength for peak absorption in water), and it is possible to increase energy absorption four times greater than conventional fiber laser systems used as the current standard of care market today. Also, the super pulsed fiber laser provides ergonomic and environmental benefits.

Compact and efficient design

This laser system is very compact compared to similar systems; for example, it fits on a standard wheeled OR cart, as well the fiber laser demonstrates higher efficiency, while it needs just a standard 110-volt power outlet. The fiber laser system is significantly quieter than other systems, producing 50% less noise at comparable settings.

Selective sintering with fiber laser technology

The selective sintering based on fiber laser technology is considered to be a process that applies a laser system to heat powder materials, leading to the fusion of micron-scale particles to create a solid mass. This technique finds its popularity in numerous manufacturing processes today. Previously, laser technology has been limited to printing with one material at a time.

Overcoming the limitations of single-material printing

The problem has been overcome by changing the whole laser system process to provide printing with multiple materials. Scientists moved the fiber laser so that it points upward instead of downward into the heated place, leading to no need for a powder bed.

Use of glass plates and powder coating

The scientists installed several transparent glass plates, and they coated them with a thin layer of various plastic powders. They make a print platform lower onto the upper surface of one powder, therefore, directing a laser beam of high quality upward from below the plate and through the bottom.

Advantages of multi-material sintering

This fiber laser technology enables numerous materials to either be combined into a single layer or stacked. Thus, a large powder bed is not required anymore because it promotes the sintering of various powders in a single layer. Also, a prototype laser system has already been tested and shows “a 50-layer-thick, 2.18-mm sample out of thermoplastic polyurethane (TPU) powder with an average layer height of 43.6 μm, and a multi-material nylon and TPU print with an average layer height of 71 μm.”

The fiber laser system for 3D printing offers such qualities as the feasibility of the process and the capability to make stronger, denser materials by pressing the plate hard against the hanging part during the process of sintering by the fiber laser.

Future applications of fiber laser 3D printing

Finally, the scientists claim that laser technology is regarded as highly promising and can find potential applications in printing embedded circuits, electromechanical components, and even robot components. Laser beams enable to production of machine parts with graded alloys, whose composition transforms gradually from one end to another.

Expanding opportunities for additive manufacturing

The opportunities of laser systems for sintering will be greatly expanded toward a wider variety of industries by allowing the production of complex multi-material parts without assembly. The fiber laser technology can change the additive manufacturing industry from printing only passive uniform parts, toward printing active integrated systems.

Fiber lasers and geothermal drilling efficiency

The high-powered fiber laser system demonstrates high efficiency during field testing to make hard rock weaker, improve the cost of geothermal drilling, and a laser beam process applied to achieve geothermal heat that is considered to be a clean and stable source of energy.

Problems of traditional drilling

The drilling process deep into the earth’s crust leads to an increase in the drill bit temperature; in this case, the drill bit wears faster and its penetration rate reduces. The cost of drilling without fiber laser application is extremely high, and this problem deters investors from being involved with deep geothermal projects.

New fiber laser technology for hard rock drilling

Nevertheless, a team of researchers from Germany has developed a fiber laser technology for laser beam drilling of hard rock that potentially allows both enhancing the penetration rate of geothermal drilling and saving the cutting edge of the bit by loosening and destroying the rock immediately before the drilling begins.

Operating principle of the developed system

The operating principle of the system developed is based on the installation of a ytterbium fiber laser (with an output power of up to 30 kilowatts) on a test rig. The fiber laser system has already been tested on such materials as sandstone, granite, and quartzite, all of which are regarded as hard rocks with a strength of more than 150 megapascals.

Role of water-jet and laser optics protection

The researchers apply a water-jet to direct the laser beam to the rock face, like an optical fiber directs the laser beam. This fiber laser technology protects from contamination and damage to the sensitive laser optics and simplifies the removal of the rock debris by the drilling device. Then the team employs “the laser system on the drilling rig in a specially developed drill string and tests the new tool under realistic conditions in field trials, which also proved to be a success.”

Future improvements of fiber laser drilling

Additionally, the researchers plan to further increase the distribution of the laser beam power and add several sensors to the hybrid device to receive feedback from the drilling process by the fiber laser system, resulting in the opportunity to respond to changes in material along the drilling path.

Adjustable laser power for drilling processes

It is possible to quickly adjust the output power of the fiber laser, making it particularly helpful in drilling processes. This type of drilling system, based on fiber laser technology, allows decreasing the cost of deep geothermal drilling in the future and expanding the application of geothermal energy as an inexhaustible source of energy, replacing other renewable sources, for example, sunlight, wind, and water.