Contribution to the achievement of SDGs
by Furukawa Electric Group

Development of the “InfraLaser” Systemand the Laser Blasting Method
for the Structure Repair of Infrastructures
Kazuyuki Umeno*1, Ryosuke Nishii*1, Keita Sakuyama*1, Manami Saito*1, Hiroki Iwabuchi*1,
Shinji Sato*1, Hiroki Miyazaki*1, Kodai Terashita*1, Masami Kawamata*1, Hideki Oda*1, Takuya Maki *1,
Hajime Kurosawa*1, Yoshihiro Nishigata*1, 2, Hirokazu Take*1, Shusuke Kaya*1, Kazutaka Nara*1
In the repair works of Japan’s infrastructure maintenance and management,
there is a need to develop a technology that can easily remove coating and rust
without a thermal effect on the base material, and the laser blasting technology, which canachieve this by only emitting laser beams, is a candidate for this goal. In various fields of infrastructure maintenance and management, we have been progressing on an agile system productdevelopment based on customer’s feedbacks in accordance with our in-house systematized new
business development process. In this report, we will describe the development of the“InfraLaser” system and the laser blasting technology, where we apply a high-power laser andthe processing technology that we have cultivated. The laser blasting technology can remove
coating and rust faster than existing methods without affecting the base material, and is expected to be friendly to both workers and environment.

ABSTRACT1.

INTRODUCTION

Since structures of Japan’s infrastructure were intensively
developed after the period of a rapid economic growth,
the problem of aging has become more serious in recent
years. It is said that the number of facilities that are morethan 50 years old since their constructions will increase
dramatically in the near future1). Structures of infrastructures include the road field (bridges, tunnels), the electric
power field (towers, electrical structures), the railroad field(towers, bridges, rolling stock, tracks, electrical structures), the industrial plant field (tanks), etc. for terrestrial
infrastructures, and the ship field (hull plates, decks, port
facilities), etc. for offshore infrastructures, and they arevery diverse. Workers are indispensable for these repairs,
but repair sites have a strong image as so-called “3D:Demanding, Dirty, Dangerous” workplaces, and it is said
that workforce availability becomes more difficult. In addition, there is a 2024 issue of capping overtime hours intransportation and construction industries for the work
style reform. Therefore, in a society with a declining population and rapidly aging society with fewer children, theamount of work per worker will have to be reduced. At
the same time, it is assumed that the difficulty of securing
workers will also increase. As a result, it can be said that
Global Marketing Sales Division,
Social Design & New Business Development Department*2
R & D Division, Photonics Laboratory*1

the maintenance and management for Japan’s structuresof infrastructures is becoming increasingly difficult. In
recent years, the use of high-power lasers as a surface
treatment method in the field of infrastructure maintenance and management has been attracting attention 2).
Since our establishment in 1884. we have been contributing to infrastructure constructions through the manufacture of power and communication cables. Contributing
to maintenance and management of Japan’s infrastructures is an important theme for us in order to protect
safety, security, and comfort of people's lives in the
future. Photonics technology, which we have cultivatedthrough optical communications and laser processing, is
one of our core technologies. With regard to a high-power Fiber Laser (FL), which is very effective in the laser
method, we are one of the few Japanese manufacturersthat can consistently manufacture a FL oscillator in addition to internal components such as semiconductor
lasers for pumping, special optical fibers, fusion splicers,
delivery cables, etc. at our group and affiliated companies3). In addition, we are developing laser heads andhigh-power FL systems for infrastructure maintenanceapplications. Japanese customers expect us, Japanesemanufacturers, to provide Japanese-based training forfield workers, domestic maintenance support, and business continuity in the Japanese market in the era ofVolatility, Uncertainty, Complexity, and Ambiguity (VUCA).
From these perspectives, our customers can also feel the
security and the Japanese style communication as values.
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Development of the “InfraLaser” System and the Laser Blasting Method for the Structure Repair of Infrastructures

We have newly launched the “InfraLaser” as a brand for
our infrastructure maintenance business as a surface
treatment solution for structures of infrastructures using
high-power FL systems, and are further promoting rapid
new business development and business expansion into
this infrastructure maintenance market. This report
describes the development of the “InfraLaser” systemand the laser blasting technology for the repair of railroad
and shipping fields.

2.

COMPARISON OF EXISTING SURFACETREATMENT METHODS AND OUR
LASER BLASTING METHOD

Advantages of the laser method over surface treatment
methods including existing blasting methods are listed
below.
(1)	Laser processing is possible with only the availabilityof a power supply, and no raw material is required.
(2)	Industrial waste disposal costs associated with processing is extremely low.
(3)	Salt removal by dry method is possible and return rustcan be delayed.
(4)	Vibration and noise during processing is extremely low.
(5)	Since there is no reaction force during processing, theload to workers is low.
(6)	It is suitable for automation and can be mounted on
robots, drones, etc. in the future.
Based on above features, if the surface treatment
method using lasers on the same level of the blasting
method can be put to practical use, this method will befriendly to both environment and workers, and it is also
expected to be a labor-saving technology of the future.
Broadly categorizing materials subject to repair structures of infrastructures, metals with anti-corrosive paint

Table 1and concrete are the two major applications. In particular,
metals with anti-corrosive paint account for many of themand removing deep rust that occurs in severe salt damage areas and aged anti-corrosive paint simultaneously
becomes an issue. Table 1 shows a comparison of existing surface treatment methods, including existing blasting
methods, and our laser blasting method. Surface treatment method and surface preparation prior to new paintare generally called “Keren” and are classified into 1st to
4th type. 1st type of Keren refers to the complete removalof black scale or red rust, which is an oxide layer of iron,and old coating using the blasting method to expose
clean steel surface. 2nd type of Keren refers to theremoval of red rust and old coating using wire brush or
mechanical tools (needle scaler, disk sander, etc.) toexpose the steel surface, but the removal is not complete
and also, primer or rust inhibitor can remain.
As shown in Table 1, our laser blasting method(InfraLaser method) can handle from equivalent to 1st
type of Keren to equivalent to 2nd type of Keren by varying the output power. In addition, compared to othermethods, our laser blasting method has the advantage ofbeing more friendly to both workers and environment interms of salt removal, consumables, industrial waste,
dust countermeasure, noise countermeasure, and reaction force countermeasure. Since the method is a blasting
method that emits a laser beam onto the object, the only
supply needed is electricity from a power source, and inorder to enter the market, where common engine generators used in ordinary construction work are available foroutdoor use, it is important to have a faster processing
speed than existing methods. Therefore, it can be said
that the goal is to achieve a processing speed equivalent
to or faster than the fastest sand blasting method.

Comparison of existing surface treatment methods and our laser blasting method.
Our Laser blasting method

Sand blasting

Wet blasting

Machine tools

Stripper

Keren degree

Equivalent to 1st type
Equivalent to 2nd type

1st type

Equivalent to 1st type

2nd type

Equivalent to 2nd type

Rust and coating removal

◯

◯

◯

△

△

×

×

Salt removal◯△

×Easy to return rust

Processing speed

△−◯

◯

△−◯

×

×
Multiple applications
with water-based
stripping solution

Consumables◯

×−△Abrasive (circulatingtype is also available.)△
Water (circulating typeis also available)

×
Abrasivematerial

×
Stripping solution

Industrial Waste
Countermeasure◯×
Abrasive + Coating×
Drainage + Coating◯×
Stripping waste liquid+ coating

Dust Countermeasure

◯

×

◯

△

◯

Noise Countermeasure

◯

×

×

×

◯

Reaction countermeasure

◯

×

×

×

◯

Remarks: 〇 Optimal △ Suitable × Unsuitable

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Development of the “InfraLaser” System and the Laser Blasting Method for the Structure Repair of Infrastructures

3.

CHALLENGES OF EXISTING LASER
CLEANING TECHNOLOGIESThe surface treatment using the laser is based on theprinciple of the “laser ablation”. This refers to the phenomenon that surface constituent materials are released
and transpired explosively either through laser lightabsorption and thermalization or with the subsequentplasma generation when high-power and high-density
laser light is beamed onto the substance. Figure 1 shows
the schematic diagram. Since the optical absorption rateof the laser beam differs between the rust/coating andthe base material (e.g., steel or aluminum), it is possible
to remove only the rust/coating or to form an anchor pattern to the base material together with the rust/coating
removal, depending on the laser emission conditions.
Laser
Transpiration

Rust/Coating

Absorption

Base Material

Figure 1

Schematic diagram of the coating removal using thelaser.

The technology currently in practical use is called the“laser cleaning”. In recent years, “laser cleaning” systems
seen at exhibitions and on video websites are often
equipped with nanosecond pulsed lasers with an average
optical output power of several tens to several hundredsof watts class 4), 5). We also have a history of developing
similar pulsed FLs and the pulsed FL-related componentsthat make them up 6), and we will describe some challenges of the pulsed method that we are recognizing. The
laser oscillator systems include a pulsed solid-state (Nd:YAG) laser in the 1064 nm wavelength band and, more
recently, a system equipped with a pulsed FL. The “laser
cleaning” using the pulsed method is effective in removing machine oils and thin rust that forms on molds, andhas been used in factory production processes for longtime. On the other hand, it is difficult to remove deep rustand thick anti-corrosive coating formed in heavy salt
damage areas in a short time, and we receive commentsfrom customers that improvements are needed in termsof speed compared to the processing speed of existing
methods.
Nanosecond pulsed lasers with an average optical output of 500 W to 1 kW class can also achieve the coating
removal under certain conditions. On the other hand,since the laser is emitted in pulses, the processing phenomenon occurs only when the pulsed laser oscillates,
and it is necessary to scan the laser spot back and forthmany times on the same spot, so improvement of theprocessing speed is a challenge. In this power band, thepeak optical output is also high, ranging from several kW
to 10 kW, so damage due to the laser ablation of the basematerial and thermal effects on the base material due tothe continuous emission become problematic (later mention). In the case of the pulsed FL method, in addition to
the peak optical output, the optical density is also high,so more attention must be paid to the damage caused bylaser ablation of the base material. The overall problem
with the pulsed laser system is that the power supply issupplied according to the peak optical output, so thepower supply capacity required is large compared to theaverage optical output, and the housing size is huge,making it difficult to operate in the field. In addition, inmany cases, a power transformer is required separatelyfrom the main unit if the product is made overseas.

4.

FEATURES OF OUR LASER BLASTINGMETHOD

In order to realize a compact and easy-to-use system, we
believe that a continuous wave (CW) type FL with a wavelength of 1070 nm, which generally has an electro-optic
conversion efficiency of 30% or more and has an extremely high laser beam quality, is suitable. In order to increase
the processing speed, it is effective to increase the optical
output of the CW-FL. On the other hand, if the amount ofheat emitted from the CW-FL onto the steel surface islarge, the steel surface will melt at the same time as thecoating is removed, causing a thermal effect on the basematerial. At the same time, the black scale, which is a stable oxide layer of iron, is formed on the molten steel surface. Since the black scale inhibits adhesion with thepaint, in order to process at the same level of 1st type ofKeren, it is our technology challenge to suppress the thermal effect on the steel material while applying high optical
output CW-FL to increase processing speed. Although wewill not go into details, we have solved this problem bymaking full use of our unique optical technology.
Table 2 shows the comparison of existing surface treatment methods using the pulsed laser and the CW laser
method. In addition, Figure 2 shows cross-sectional
microstructures of coated steel SM400B after the laser
blasting using the pulsed laser method and our CW laser
method (Chapter 6 Development of the “InfraLaser” system for the railway vehicle bogie repairs), respectively.
The pulsed laser method and the CW laser method werecompared with an average optical output of 500 W and a
CW optical output of 500 W, respectively. In the pulsed
laser method, since the peak optical output is several
KWs and high, a spatter is generated during the laser
blasting, resulting in the thickness reduction. On the other
hand, in our CW laser method, a normal processed surface after removing the coating was obtained without
thickness reduction. After the laser blasting shown in
Figure 2, we evaluated the Vickers hardness Hv from thefront surface to the back surface for the steel material toinvestigate the thermal effect (Figure 3). In the pulsed
laser method, since it takes time to remove the coating,
the Vickers hardness Hv increases near the surface andFurukawa Electric Review, No. 55 202440

Development of the “InfraLaser” System and the Laser Blasting Method for the Structure Repair of Infrastructures

Table 2Comparison of existing surface treatment method
using the pulsed laser and the one using the CW laser.
Pulsed laser method
Laser oscillation

Continuous Operation

OutputPeak optical output

OutputImage of laser
oscillation

CW Laser Method

Intermittent operation

Average optical output

Laser oscillation

Time

Time

Advantages• Minimal thermal effects on base material.

Disadvantages• Slow processing speed.
• Thermal effect on base material occurs when
average output is increased for coating removal.
• Power supply capacity needs to be adjusted topeak optical output.
• Thermal effect occurs when power is increased.

Pulsed laser method
Our CW laser (InfraLaser) method
CW optical output 500 W
Average optical output 500 W

100 µmFigure 2100 µmCross-sectional microstructures of coated steel
SM400B after the laser blasting using the pulsed
laser method and our CW laser method, respectively.

Vickers hardness / Hv

300
250
200
150
100

Pulseｄ laser method
Our CW laser (InfraLaser) Method
Solid steel SM400B

50
0

0

100

200

300

400

• High processing speed.
• Smaller power supply capacity.
• Thermal effect occurs.

Solved by our original
optical technology.

for each sector. In infrastructure maintenance and management field, since the anti-corrosive paint used are different, it is necessary to develop a prototype laser processing system and a processing technology appropriate
for each sector. Therefore, we are developing the“InfraLaser” system by utilizing the new business creation
process at fuzzy front ends. Our new business development process is described in detail in Reference 7).
Table 3 shows the development process of the“InfraLaser” system based on our new business creation
process. In Phase 0, we will build a hypothesis where alaser processing method can be applied in the field of
infrastructure maintenance and management. In Phase 1,
we will conduct job searches based on hypotheses in awide range of repair segments. In Phase 2, a concept
prototyping, experimental equipment will be constructedby combining existing industrial laser equipment (latermention). In the creation of a verification field in Phase 3,
since it is important for customers to experience our laser
blasting, we opened the “InfraLaser Lab” at our Chiba

Distance from surface / µm
Figure 3

Evaluation results of Vickers hardness Hv from thesurface to the back side for the steel after the laser
blasting shown in Figure 2. Evaluation results forsolid steel SM400B are shown as a reference.

the steel material is softened. On the other hand, in our
CW laser method, the Vickers hardness overlaps with thereference solid steel SM400B’s Vickers hardness Hv, it isconfirmed that there is no heat effect or black scale generation during the coating removal.

5.

METHODOLOGY FOR DEVELOPING
THE “INFRALASER” SYSTEM

In the structures of infrastructure, since the objects to be
repaired differ greatly depending on the industry sector,
and also, the work-sites are different, systems that we
receive as needs are different in many cases. Therefore,
the laser blasting technology also needs to be optimized

Table 3Development of the “InfraLaser” system based on
our new business creation process.

Development
phase

Action item

Action items in the InfraLaser systemand the method development

Phase 0Knowledge
acquisition

Hypothesis building for the applicationof the laser method in the repair fieldof infrastructure maintenance andmanagement.

Phase 1

Job search

Job search through the introduction ofmaterials to customers, etc.

Phase 2Concept
prototyping

Minimal experimental facility
construction combining existing
industrial laser products.

Phase 3

Verification
field creation

Invite customers to visit the InfraLaser
Lab to experience laser processing.

Phase 4

Product
prototyping

Creation of an MVP by bundlingcustomer feedback in Phases 1- 3 andfield verification test.

Phase 5Business
scenario
sharpening

Completion of the product realization
process, including specification anddesign review (DR), and finalization of
the sales format.

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Development of the “InfraLaser” System and the Laser Blasting Method for the Structure Repair of Infrastructures

Works in January 2023 as a base for co-creation withcustomers (Figure 4) 8). In Phase 4 product prototyping,
we will compile the feedback obtained at the “InfraLaser
Lab” and create a Minimum Viable Product (MVP) basedon the lean startup method. Since field verification test isalso required for structures of infrastructure, we have also
prepared a transportation truck for field verification test
as shown in Figure 5. In addition, we are also the manufacturer of metal materials, mainly copper, where themetal technology is one of our core technologies.
Metallurgical evaluation of base materials such as steel
and aluminum can be performed by ourselves. On theother hand, since we have limited knowledge in structural
materials, we are conducting joint research with Kyoto
University in an industry-academia collaboration to evaluate it.

Figure 4

Figure 56.

DEVELOPMENT OF THE “INFRALASER”
SYSTEM FOR THE RAILWAY VEHICLE
BOGIE REPAIR

Figure 6 is an external image of the compact “InfraLaser”
system that has passed Phase 4 of the development process shown in Table 3 and is scheduled to begin receiving orders from March, 2024 in Phase 5 9). Since the welded parts of steel structures such as railway vehicle bogies
are important for maintaining strength, there is a casewhere regular inspections are mandatory by law.
Figure 7 shows a picture of work with this product.
Traditionally, mechanical tools such as needle scalers andsanders have been used to remove the protective coatingfrom these welds, but dust, noise, and vibrations generated during the work put a burden on workers and became
problems. In order to solve these problems, we developed and equipped a lightweight handheld laser head(weighing less than 2 kg) that can be safely operated with
one hand, and that is designed to be easy to handle during maintenance. The flexible delivery cable with a lengthof 20 m is used, and the design with a consideration foran easy of handling on work-site was applied. The power
supply capacity is also compatible with a three-phase
200V/20A power supply.

The InfraLaser Lab opened at our Chiba Works.
Left: Exterior view of the building,right: Experiment space in the InfraLaser Lab.

Figure 6External picture of the compact “InfraLaser” system.

Figure 7

Picture of the processing work with our laser
blasting method.

The InfraLaser truck for the field verification test.

Finally, Phase 5 will be the sharpening, which is the
final step of the business scenario. Here, the product will
be formally specified, a Design Review (DR) will be conducted based on the ISO9001 quality management system, and then, the commercialization process will becompleted. We will also work with the sales department
to establish the form of sales and maintenance. Toward
the social implementation, we are actively providing education and suggestions for customers to use the“InfraLaser” systems safely while gaining a good understanding of customers’ worksites.

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Development of the “InfraLaser” System and the Laser Blasting Method for the Structure Repair of Infrastructures

Table 4Comparison of laser processing results using machine tools (needle scaler) and those using ourlaser blasting method.
Machine tools (Needle Scaler)

Our laser blasting method

Cross-section view
100 µm

100 µmNo change in microstructure.

No change in microstructure.

Sample appearance
10 mm

10 mm

With paint residue.

No paint residue.

Acrylic water-based paint, Gray color, Paint thickness: approx. 100 µm

Paint information

Ti
Residual element mappingby Electron Probe
Micro Analyzer (EPMA)
after processing

TiO

200 µm200 µmPaint residue present.

*Assessed by titanium (Ti) in paint components.

Processing speed / m2/h

In the development, we conducted an evaluation oflaser processing on the coated steel for railway vehicle
bogies. As a test specimen, we prepared a steel material
SM400B with a thickness of 9 mm with approximately
100 mm. Its surface is painted with an acrylic paint (greycolor). and the comparison after removing the coating
using the mechanical tools method (needle scaler) andour laser blasting method was carried out. Table 4 shows
the comparison results. As shown in Figure 8, processing
speeds in these cases were 0.2 and 1.4 m2/h using themechanical tool method and our laser blasting method,respectively. Compared to existing mechanical tool methods, our laser blasting method can achieve a processing
speed approximately seven times faster, and are also
considered to be effective in a labor-saving in term of thework efficiency.
1.4 m2/hApprox. 7 times
faster

0.2 m2/h
Machine tools

Figure 8

Our laser blasting method

Comparison of laser processing results using
machine tools (needle scaler) and those using ourlaser blasting method.

Comparing the optical microscope image and the surface photograph of the cross-sectional metal structure ofsteel material SM400B after the processing shown in
Table 4, no difference was observed in the cross-sectional metal structure between the two after the processing.

O

No paint residue, No surface oxidation.

*Surface oxidation is determined by oxygen (O).

Next, a comparison of elemental mapping of titanium andoxygen using an Electronic Probe Micro Analyzer (EPMA)
revealed that residual titanium contained in the paint andoxygen on the surface were detected in the mechanicaltool processing. On the other hand, these elements were
almost not detected in the laser processing. In general,the coating removal using mechanical tools is equivalent
to 2nd type of Keren, which can be said to be a reasonable result with a small amount of paint residue remaining. In the laser processing, the surface of the SM400B
steel material can be clearly exposed, and can be considered that the laser blasting technology is equivalent to 1st
type of Keren. Furthermore, under these laser emission
conditions, it has been confirmed that there is almost no
thermal effect on the base material even after repeatedemission 50 times. Additionally, safety has been confirmed that there is no change in the condition of pork or
work clothes, which are intended to be skin, if the product is applied once by mistake under the same conditions
as the laser processing. To prevent such accidental emission, the laser is fully equipped with an interlock, so
workers can work safely by wearing laser safety goggles
and work clothes with long sleeves and long pants.

7.

DEVELOPMENT OF THE “INFRALASER”
SYSTEM FOR THE SHIP HULL PLATEREPAIR

Ship transportation accounts for 99% of Japan’s trade,and ships are important offshore infrastructure. Ships are
required to undergo periodic inspections, and ships enter
docks, and inspections and repairs are carried out. Sand
blasting method shown in Figure 9, which shows a working view, is often used in ship hull plate repair (rust andFurukawa Electric Review, No. 55 2024

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Development of the “InfraLaser” System and the Laser Blasting Method for the Structure Repair of Infrastructures

coating removal) in Japan. The sand blasting method has
issues in terms of its impact on the atmosphere andoceans due to the release of abrasive materials. The
replacement to the laser blasting method, which emits
extremely little waste, is expected to reduce the environmental burden and to improve the occupational health.
On this assumption, Tsuneishi Shipbuilding Co., Ltd.
(Located in Fukuyama City, Hiroshima Prefecture) wasinterested in this and provided us with a field verification
test for the development of the “InfraLaser” system forship hull plate repair10).

the “InfraLaser” system in the future (Figure 12). In this
optical configuration, it is possible to emit laser beams
with a width of 60 mm, and the laser blasting processingof approximately 20 m 2/h is possible on the steel rusted
in heavy salt damage areas. This is a water-cooled laser
head that can achieve processing speed that is equal toor higher than the one of sand blasting. Based on thedevelopment process shown in Table 3, we are proceedingwith a product development toward the commercialization in 2025 with a system that is friendly to both people
and environment in the shipbuilding industry.

Figure 9

Figure 10 Field verification test at Tsuneishi Shipbuilding
Corporation using the conceptual prototype
equipment.

Sand blasting operation.

Based on the development process shown in Table 3, aconcept prototype of Phase 2 was constructed usinga 6 kW optical output FL used in laser welding applications and a Galvano scanner for laser welding. In addition,
regarding Phase 3, in this case, as shown in Figure 10,
a complete set of equipment was brought to Tsuneishi
Shipbuilding Co., Ltd., and a laser emission experiment
was carried out outdoors in May 2022, using rusted steel
plates in heavy salt damage areas and a portion of ship
hull plate as a ship. At this time, the processing speed forrusted steel plates in heavy salt damage areas wasapproximately 5 m2/h. In order to handle thicker coatingsuch as ship hull plate repair, it is necessary to master theuse of laser beams with higher optical output and toachieve a processing speed equivalent to sand blasting.
Customers told us that the welding Galvano scanner(approximately 25 kg) as processing equipment is far
from a practical use in terms of weight. Then, we wereable to recognize once again development issues.
Therefore, in preparation for Phase 4, we began to develop a water-cooled laser head that is more compact, lighter, and capable of high-speed laser processing.
Figure 11 shows the developed water-cooled laser
head with an optical output of 6 kW, the state when thelaser is emitted onto a steel material (SS400) deeply rusted in heavy salt damage areas, and a photograph after
the laser emission. The water-cooled laser head is lightweight, weighing approximately 4 kg. In addition, sinceno reaction force is generated during laser processing.
we are developing an ultimate labor-saving technologythat can be equipped on robots and other equipment as

60 mm

Figure 11 The 6 kW compatible laser head (upper left), the state
during the laser emission (right), and the picture after
the laser emission (lower left).

Figure 12 Image of the future development of the “InfraLaser”
system for ship’s hull plate repair.

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Development of the “InfraLaser” System and the Laser Blasting Method for the Structure Repair of Infrastructures

8.

CONCLUSION

This report described the development process of the“InfraLaser” system and the laser blasting technology, as
well as examples of development in the railroad and shipbuilding fields. The compact “InfraLaser” system for therailroad field can achieve a processing speed about
seven times faster than that of conventional mechanicaltools. Since the hand-held compact laser head enables
easy operation without reaction force, the worker's workload can be reduced. In the ship field, we reported on thedevelopment of a water-cooled laser head that canachieve a processing speed equivalent to the existing
sand blasting method. Since no reaction force is generated during laser blasting, we are promoting the use of
automated robots as the ultimate labor-saving technology. Infrastructure maintenance and management fields
are extremely vast, and we are planning to develop andpropose optimal systems for other fields and sectors
besides ships. we hope to contribute to Japan’ infrastructure maintenance and management as a domestic manufacturer capable of designing and manufacturing optimallaser systems in the field of infrastructure maintenanceand management. Laser blasting technology using the“InfraLaser” is expected to be implemented in society as
a very easy coating and rust removal system by increasing the speed of coating and rust removal beyond that ofexisting methods without affecting the base material. We
hope to contribute to the “realization of safe, secure, andcomfortable lifestyles,” as stated in our Group Vision
2030, through the society implementation in the field ofJapan’ future infrastructure maintenance and management.

REFERENCES
1) White Paper on Land, Infrastructure, Transportation and Tourism
in Japan, 2022, 117, (in Japanese).
2) Kazuhisa Fujita, Kor yu Kamei, Yoshinori Kawamori: “Opticaltechnology for the management of infrastructure structures
Application of CW laser cleaning technology to infrastructure
maintenance management”, Optics, 50 (2021), 68-74, (inJapanese).
3) Takashi Kayahara, Kazuyuki Umeno, Takefumi Takagi, Yoshihiro
Emori, Akira Fujisaki: “10 kW fiber laser and their process characteristics”, Journal of Japan Laser Processing Society, 26 (2019),
27-32.
4) Kosaku Motomura: “High power laser cleaning device in plantmaintenance”, Piping Technology, 62, (2020), 66-71, (in Japanese).
5) Naoya Oami: “Cleaning technology using laser - Development tobridge applications such as removal of coating and rust –”,Welding Technology, 71 (2023), 65-68, (in Japanese).
6) Ryo Kawahara, Hiroshi Hashimoto, Jeffrey W. Nicholson, E.
Otani, Shunichi Matsushita: “The development of a high quality
and a high peak power pulsed fiber laser with a flexible tunabilityof the pulse width”, Furukawa Electric Review, 49 (2018), 43-48.
7) Kiyoshige Hirose, Katsuki Suematsu, Junya Hirano, Kazutaka
Nara: “The modeling of a new business creation process based on
the development of a road sign inspection suppor t system”,
Furukawa Electric Review, 51 (2020), 11-17.
8) Furukawa Electric HP > News Releases > Establishment of the“ InfraLaser Laborator y,” The Co-Creation Base of Sur face
Treatment Solutions for Structures of Infrastructure (Referred
on: Jan. 26, 2023), (in Japanese).
9) Furukawa Electric HP > News Release > Commercialization of aCompact Laser Processing System Ideal for Railway Maintenance(Referred on Oct. 23, 2023), (in Japanese).
10) Furukawa Electric HP > News Release > Furukawa Electric andTsuneishi Shipbuilding Commence Verification test for theDevelopment of Rust and Coating Removal System (Referred on
Nov. 30, 2023), (in Japanese).

ACKNOWLEDGEMENT

The evaluation of laser processed steel was conductedin collaboration with Professor Yasuo Kitane of Division of
Civil and Earth Resources Engineering, Graduate Schoolof Engineering, Kyoto University. We would like toexpress our gratitude to Professor Yasuo Kitane.

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