A SEMINAR ON
LASER PROCESSING OF MATERIALS &
ITS INDUSTRIAL
APPLICATIONS
 CONTENT OUTLINE
 Introduction
 Applications

Lasers materials processing in Mechanical Industry

Laser Micro machining (MEMS)

Laser processing on electronic materials

Laser processing of Chemical materials

Laser processing materials for Nuclear energy

Laser processing for photovoltaic application

Laser materials processing in Nanotechnology

Laser processing for medical industry
 Introduction
 Laser materials processing is done on various materials such as metals,
non metals, ceramics, polymer materials.
 CO2 and Nd:YAG lasers are known as industrial lasers which are widely
used in industries.
 Laser processing is used in various industry such as mechanical industry,
electronic industry also used in chemical processes, nuclear
technology, nano technology, micro machining.
 So, we can say that laser can perform all technological task.
 Type of Industrial Lasers
 Solid state lasers



Nd:YAG (1064 nm)
Ruby (694 nm)
Nd:glass(1062 nm)
 Gas lasers



HeNe (632.8 nm)
CO2 (10,600 nm)
Argon (488, 514.5 nm)
 Liquid dye lasers
 Rhodamine 6G (570 – 640 nm)
 Coumarine 102 (640, 515 nm)
 Stilbene (403-428 nm)
 Semiconductor laser
 InGaAs (980 nm)
 Type of lasers
 Lasers widely used in material processing are CO2 laser and
Nd:YAG laser.
• CO2 Lasers :

CO2 lasers operate at 10.6 nm and metals have high reflectivity at this wavelength.

Instead of CW CO2 laser, a pulsed mode CO2 laser produces high peak powers and
makes possible to work on metals.
• Nd:YAG lasers :

Nd:YAG lasers operate at 1.06 nm where metals are less reflective and are better
candidates for working on metals.

Nd:YAG lasers offer the advantage of compactness.
 CO2 lasers are cheaper compared to Nd:YAG lasers.
 CO2 lasers are more generally preferred.
 Lasers materials processing in
Mechanical Industry

Laser processing of materials
 Laser Finishing
 Laser Engraving
 Laser Marking
 Laser Machining
 Laser Milling
 Laser Sweeping
 Laser Striping
 Laser Striping
 Laser Cutting
 Laser Carving
 Laser Drilling
 Laser Cooling
 Laser Welding
 Laser Heating
 Laser Etching
 Laser Sealing
Laser cutting
Laser drilling
Laser welding
Laser Engraving
Laser etching
Laser marking
 Mechanical Processing on both Metals and Non metals.

Processes require transfer of energy from the laser beam to the work piece.

Happens only if the material has high absorption at the wavelength
corresponding to the laser beam.

Once the surface of the materials absorbs energy, the material starts to melt
and then vaporise.

At high intensity of radiation, the vapour will be ionized to produce
plasma.

Plasma layer formed between the laser and the work piece prevents the
laser beam from reaching the work piece.

Essential that plasma should be removed to increase energy coupling.
Energy Absorption during Mechanical Processing

Laser should deliver large amount of power.

Intensity of laser beam can be enhanced with a suitable optical system that can
focus the beam into a spot of about 10 to 100 m diameter.
 Laser Micro machining
(MEMS)
 Micro Machining is to ablate or machine small amount of material from the surface of sample.
Intense pulses of UV light from UV lasers are used for such purposes.
Nd:YAG pulse laser is used for micromachining.

The technique is used for
machining of fine, micron-sized
features in polymer materials, for
micro-hole drilling, selective thinfilm removal, surface engineering
and milling for 3-D microstructuring.
Laser micromachining
 Laser processing materials for
Nuclear energy

In Nuclear power plants, natural uranium is used to fuel the fission reactor.

Natural uranium ore mainly contain two principal isotopes U-238 and U-235.

U-238 is the more abundant isotope but it cannot sustain the fission chain reaction
needed to drive the nuclear reactor.

It is U-235 isotope that sustains a fission reaction.

Differences in the nuclear mass shift the electronic energy levels slightly and
therefore each isotope absorbs light at different characteristic wavelength.

Absorption bands are fairly narrow and lie close to each other.

If the mixture of isotopes is irradiated by a source of narrow bandwidth, it is
possible to excite one isotope without disturbing the other.

Lasers have very narrow bandwidth and can be helpful in this process.

Desired energy can be obtained by tuning a Dye laser to a precise wavelength
with a very narrow bandwidth.

Selectively excited U-235 atoms can
be ionized by applying another short
wavelength light to the mixture.

Ionized U-235 atoms can be
separated from the neutral U-238
atoms using electrostatic fields.
Schematic of Uranium isotope
separation facility
 Laser isotope separation
 Atomic vapour laser isotope
separation (AVLIS) process
for Uranium enrichment,
(Livermore, USA).
 Green light is converted to
red–orange light of three
different wavelengths that
are absorbed only by
Uranium-235.
 Laser materials processing in
Nanotechnology

Nanoparticles, Nanomaterials and Nanostructures are building blocks of nanotechnology.

Advanced laser based techniques developed to fabricate nanostructures on polymer surface;
succeeded in producing periodic feature < 200 nm in width.
Periodic nanostructures
on polymer surface

Cellular response is modified in the presence
of the nanostructures.

Ability to fabricate these structures could also
have an important impact on a wide range of
electronic and photonic devices.
 Laser induced “Nanojets”
 Nanojets:- self-organised structures of the order of 200 nm in diameter that are generated
through the interaction of ultrafast (femtosecond) laser pulses with thin metallic
materials coatings.
Computer simulation of lasergenerated nano jet in 20 nm Ni film
on silica.
The coloured areas
represent
regions
of
different
crystalline phase.

Structures are important in the
creation of raised nanoscale
features for biotech applications.

Also, important in the formation of
novel low dimensional structures in
ICT and in the fabrication and rapid
prototyping of plasmonic devices.
 Laser processing on
electronic materials
 Laser materials processing
 Laser Soldering
 Laser Drilling
 Laser Scribing
 Laser CB Cutting
 Laser PCB Cutting
 Laser Bar coding
 Laser Marking Data matrix
 Laser Marking IC chips
 Photolithography
Bar coding by LASER
Laser marking data matrix
CD cutting by LASER
Laser marking IC chips
PCB marking by LASER
PCB cutting by CO2 Laser
 Types of lasers
 CO2 Lasers for metallic material processing :Scribing
 ND:YAG for non-metallic materials:Soldering, Trimming
 Pulsed excimer lasers for finer features:Photolithography
 Laser processing of
Chemical materials
 Chemical processing using lasers
 Laser spectroscopic chemistry
 Laser chemical processing
 Laser chemical reaction
 Laser spectroscopic chemistry
 Laser desorption/ ionization mass spectrometry
 Molecular identification by laser spectroscopy
 Laser scanning confocal microscopy imaging
 Laser chemical processing
 Catalytic action
 Chemical coating
 Isotope separation
 Chemical vapour deposition
 Intermediate refining
 Chemical reactions using laser
 Laser flash photolysis
 Laser chemical amplification
 Laser flash chemical reaction
 Laser induced chemical reaction
 Laser study of chemical reaction
 Laser control of chemical reaction
 Laser driven chemical reaction
 Laser excited chemical reaction
 Laser simulation of super continuum generation
 Laser wave electronic steering (chemical bond)
 Laser processing for
photovoltaic application

Among laser processes for TF photovoltaics, only laser scribing systems hardly suffer
any competition from other techniques.

Laser scribing systems have the ability to machine narrow patterns on a wide range of
materials in a selective, precise, and cost-effective manner.

It is a noncontact process, meaning that the mechanical stress applied on the micro
machined layers is limited.

Unlike the tip of a mechanical scriber that suffers mechanical wear , a laser scriber when
powered by a diode-pumped solid state laser (DPSSL) can operate continuously for over
10000 hours.
 Various applications are securing a bright future for lasers in TF
photovoltaics such as,
•
Laser scribing along with other laser processes for TF
photovoltaics
•
Lasers are also integrated into various diagnostic tools to
analyze deposition processes of Si thin films
•
In the development stage of PV cells, lasers are applied in
several TF characterization methods
 Laser processing for
medical industry
 Type of Laser processing
 Laser cutting
 Laser welding
 Laser Drilling
 Laser Marking

For medical devices, the pin point precision of lasers is the most valuable technology
for cutting, welding, drilling, marking components.

Laser machining is a valuable tool for medical device component manufacturing, and the
development in laser technology have added very compelling benefits to process
capability.

Laser processing is a high performance solution for creating intricate and geometrically
complex features in advanced materials within extreme high tolerances.

No other manufacturing tool provides the same stable, accurate energy needed for
fabricating precision devices, where quality has a profound effect on patient outcome.
 Type of lasers used in medical applications
 Ruby(694 nm)
 Alexandrite(755 nm)
 Pulsed diode array(810 nm)
 Nd:YAG(1064 nm)
 Ho:YAG(2090 nm)
 Er:YAG(2940 nm)

Laser eye surgery or laser corneal surgery is a medical procedure that uses a laser to
reshape the surface of the eye. This is done to correct myopia (short-sightedness),
hypermetropia (long sightedness) and astigmatism (uneven curvature of the eye's
surface).

Hard tissue surgical lasers are dominated by Er:YAG lasers operating at the
wavelengths of 2.94 µm.

Laser eye surgery utilizes excimer lasers in the UV range of wavelengths.

CO2 lasers remain the dominant soft-tissue surgical lasers because of their wavelength
and precision.

CO2 laser surgery is praised for minimized bleeding, less swelling and discomfort,
reduced infection risk, and less procedure time, as compared to traditional scalpel
surgery. Applications include oral surgery, periodontal surgery, oncological surgery,
among many others.
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