Laser micromachining solutions

2015

Workshop of Photonics® is all about laser micromachining.

We develop instruments and solutions for laser micromachining tasks. From feasibility studies to customized optical modules and from electronic devices to laser machines.

Our services are targeted to both industrial and academic customers.

Our key competencies: Feasibility studies on femtosecond laser micromachining Development of custom femtosecond laser micromachining workstations and optical

modules Laser system automation software

Our competence growth is fueled by culture of open innovations and partnership with the Lithuanian laser sector companies and worldwide partners.

Workshop of Photonics is constantly working on projects connecting scientific inventions with the industry needs.

For more information please visitwww.wophotonics.com

Content

1. Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.1. Feasibility Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.2. Laser Process Development . . . . . . . . . . . . . . . . . . . . . . . . 5

2. Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.1. Laser Systems for Laboratories . . . . . . . . . . . . . . . . . . . . . 6

2.2. Industrial Laser Machines . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.3. Special Optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.4. Beam Shaping Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.5. WOP module for cutting glass and sapphire . . . . . . . . . 20

3. Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.1. WOP laser technology for cutting glass and sapphire . 22

3.2. Heat Sensitive Materials Scribing . . . . . . . . . . . . . . . . . . 25

3.3. Through Glass Via (TGV) Drilling . . . . . . . . . . . . . . . . . 26

3.4. 3D Additive Manufacturing . . . . . . . . . . . . . . . . . . . . . . . 27

Micromachining Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Partners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

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Workshop of Photonics cooperation with customer usually starts with a demand to perform a specific micromachining task.

The first step is a feasibility study which means that our company prepares samples for a customer to showcase achieved results and prove feasibility of laser processing. Regarding customer requirements it may lead to a small scale production if this is only a one time request. For a more demanding customer feasibility studies would lead to a laser process development - the solution how to prepare the samples would be developed together with a customer.

Pinnacle of the cooperation with the customer is designing and manufacturing custom system for a laser micromachining task. It is a customer’s choice how far to go down the steps of cooperation with Workshop of Photonics.

* In partnership with manufacturing machinery producers

Feasibility study

Design of a system/module

Custom laser systems for science Laser Machines for Industry*

Warranty, maintenance & technological support

Laser process development (laboratory prototype)

Small scale production

1. Services

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1.2. Laser Process Development

The essence of feasibility study is to demonstrate that customer’s problem can be solved using ultrashort pulsed laser micromachining technology and that it has ad-vantages over competing technologies. Workshop of Photonics laboratories are fully equiped and ready to process various materials with femtosecond and picosecond lasers and achieve desired results.

Feasibility studies are performed in following steps:

1. Detailed task description2. Samples3. Processing4. Evaluation of results5. Preparation of report6. Feedback from customer

Most of laser micromachining applications are not as straightforward as for example marking. Most of them require develop-ment that takes weeks and even months.

Not only different laser parameters have to be tested but also various beam shaping and focusing solutions.

A typical approach for a comprehensive process development contains following steps:

testing of different wavelengths in order to explore light-material interaction testing of different focusing conditions selecting and testing most suitable positioning solution determining what is required for repeatability and required speed of process optimizing software functionality for convenient process control

Every customer is welcome to contact us with specific micromachining tasks. We are committed to develop a micromachining process. If a task is more demanding, we are ready to involve our academic partners in search of a solution.

For more examples of our work please see page 30.

1.1. Feasibility Studies

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2. Products

FemtoLAB is a femtosecond laser microma-chining system for scientific laboratories. Equipped with high accuracy linear position-ing stages, high performance galvanometer scanners and versatile micromachining soft-ware SCA, FemtoLAB becomes an entire laser laboratory on an optical table.

Features: Custom design End user selected laser source Efficient beam delivery and power control Highest quality optical components High accuracy positioning stages Additional non-stadard equipment can be integrated on request

2.1. Laser Systems for Laboratories

Workshop of Photonics develops customized laser micromachining workstations - devices that fully meets customer’s requirements.

Based on customer’s requiremnts we will select appropriate configuration of the sys-tem:

Laser source Sample positioning system Beam delivery and scanning unit Laser power and polarization control Software for system control Machine vision Sample holders and special mechanics Sample handling automation (optional) Optical table Enclosure Dust removal unit

We provide a custom solution for every laboratory. A proven flexibility of FemtoLAB concept allows to further expand and upgrade the system when new requirements arise.

FemtoLAB

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Specifications for a femtosecond laser based system: Pulse duration (from 200 fs to 10 ps) Repetition rate (from 1 kHz to 1 MHz) Average power (up to 15W) Pulse energy: up to 2 mJ Wavelengths (1030 nm, 515 nm, 343 nm, 258 nm, 206 nm) Positioning accuracy: ±250 nm Travel range: customer selected

Applications: surface micro and nanostructuring, engraving, drilling, laser lithography and

multiphoton polymerization, refractive index modification inside bulk of mate-rial, selective layer removal, cutting brittle materials, waveguide fabrication, your task.

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FemtoLAB-MPP

FemtoLAB-KIT

FemtoLAB-MPP workstation is optimized for multiphoton polymerization (MPP) technology.

System layout and design is similar to standard FemtoLAB which can also be used for MPP application after minor modifications.

Instead of powerfull laser, laser oscillator can be used and for rapid fabrication we recommend to have synchronized movement of scanner and positioning stages.

Features: Very high precision in short movement range Fast prototyping Machine vision solution for samples recognition Market available photoresists

FemtoLAB kit is a unique femtosecond micromachin-ing system which can be installed next to customer’s femtosecond laser source. Depending on laser speci-fications this system can become a universal tool for micromachining of different materials. Machine vi-sion and user friendly software allows to perform vari-ous micromachining tasks easily.

Features: XYZ high accuracy sample positioning Beam delivery and shaping for selected wavelengths Control of entire system through single-window software Easily extendable, custom design 1 year warranty

Applications (*depends on customer’s laser):

Surface micro- and nano-structuring Selective ablation Micro-drilling 3D direct laser writing Refractive index modification Dicing and cutting Multiphoton polymerization (mPP)

Optional features: Galvanometer scanners Safety enclosure External safety/modulation shutter Autofocus system Spatial light modulator Polarization rotator Polarization converter (circular, ra-

dial or azimuth) Custom device integration

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FemtoFAB

FemtoFAB is a turnkey femtosecond laser machine for industrial use. Configuration is selected and carefully tuned according to a specific laser micromachining application, including laser cutting, laser scribing, laser drilling and 3D laser milling with any desir-able material (with >2,4 GW peak power). System is protected by Class 1 equivalent laser safety enclosure and is controlled through a single SCA engineer software window.

Features: High fabrication speed – up to 300 mm/s (more on request) Fabrication of complex objects with submicron resolution Minimal heat affected zone in femtosecond micromachining mode Aerotech based precise object positioning with submicron accuracy Precise laser beam control in space using high-performance galvanometer scanners Pulse number control (single to 1 MHz) Synchronization of laser pulses with moving object in space and time domains Original software interface for control of all integrated hardware devices

Specifications: Task optimized, available range is similar to FemtoLAB (see page 7)

Applications: Ceramics scribing, glass cutting, sapphire cutting, TGV drilling, solar cell man-

ufacturing, birefringent pattern fabrication, etc.

Needs of industrial customers are rather different from those from an academic laboratory: speed, repeatabili-ty and efficiency are in focus. The whole system has to be built around process. Therefore our laser solution mostly is a part of a bigger manufacturing machine or production line. Usually it is built by specialized integrators or producers of manufacturing machinery.

Workshop of Photonics develops laser micromachin-ing process and implements it into customer’s produc-tion line or designs specialized workstation. System configuration will be selected to assure quality, speed and reliability of execution of the task.

In order to automate the fabrication process, a custom adaptation of our laser mi-cromachining software SCA engineer can be designed. This will not only speed up the fabrication process, but will also reduce participation of an operator to the very minimum. On the other hand, high-level users will have a special interface to config-ure the process or add new tasks.

2.2. Industrial Laser Machines

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Laser Micromachining Software SCA provides speed, flexibility and visibility to la-ser micromachining operators. It makes fabrication tasks easy to write, fine-tune and repeat

Key benefits of the software: The software eliminates the need to work with G-code completely WYSIWYG interface Convenience in entering algorithms and mathematical commands Fast and easy to correct, fine-tune and then repeat machining task Directly controls a wide range of equipment Customizable to fit special requirement of scientific or industrial applications

Features of the software: Direct control of hardware starting with laser, positioning stages, galvanometric

scanners and going to power attenuators and power meters, polarization rota-tors, machine vision, special I/O and other peripheral devices.

DXF, PLT, STL, BMP file import Import of data from TXT or XML files Digital and analog I/O control Fabrication preview window Camera view calibrated with fabrication preview Machine vision (MV) module for sample detection

Versions of the software:

SCA Professor:

Dedicated to have control of various micromachining applications and flexible systems

Complete functionality Control of virtually unlimited num-

ber of positioning axis Machining rich in functions and op-

tions Real-time sample view through

camera Complex machining tasks

SCA Student:

Dedicated to control basic microma-chining systems

Control of 2 positioning axis / gal-voscanners

Live sample view through camera

Laser Micromachining Software SCA

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SCA Engineer:

OEM version for system integrators Adapted for specific machine and

specific task Special task optimized user interface Adapted to work together with other

software packages

SCA Intro:

Dedicated for fabrication recipe preparation

Free of charge Complete functionality for recipe

preparation Does not connect to hardware to

control it

Fig. 2.2.1. Cross-hatched shape prepared for 2.5D fabrication

Fig. 2.2.2. Machine vision automatically recognizes glass substrateand positions fabrication trajectories in the center of it

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2.3. Special Optics

S-waveplate - Radial/Azimuthal Polarization Converter (RPC)

S-waveplate is a spatially variable waveplate which converts linear polarization to radial or azimuthal polarization. The product is unique for it’s high damage threshold 100 times exceeding alternative devices*. Unique results are achieved by forming birefringent nanogratings inside a bulk of fused silica glass. Product developed in col-laboration with Prof. Peter G. Kazansky group from Optoelectronics Research Centre at Southampton University.

* According to ISO 11254 – 2 is θ1000-on-1= 22.80 ± 2.74 J/cm2, at λ = 1064 nm, τ = 3.5 ns, f = 10 Hz.

Features: Converts linear polarization to radial or azimuthal Converts circular polarization to optical vortex High damage threshold 55-90% transmission (wavelength dependent) Large aperture (up to 15 mm; standard is 6 mm) Continuous pattern - no segments

Fig. 2.3.1. S-waveplate fabricated for 632 nm, clear aperture 8 mm.Cross polarized light photo

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Standard S-waveplate models are available for 1030 nm, 515 nm, 800 nm and 1550 nm wavelengths. Dielectric anti-reflection coatings can be applied on both converter sides to further increase converter transmission. Custom wavelength (from 400 nm to 2000 nm) converters are available at request.

Applications STED microscopy Micromachining Microdrilling high-aspect-ratio channels Generate any cylindrical vector vortex Multiple particle trapping Micro-mill driven by optical tweezers Use as intracavity polarization-controlling element in cladding-pumped ytter-

bium doped Observation of photonic spin Hall effect with rotational symmetry breaking Realization of polarization evolution on higher-order Poincaré sphere Direct transformation of linearly polarized Gaussian beam into vector-vortex

beams with various spatial patterns

+ =

Fig. 2.3.2. Measured incident beam intensity distribution (left), S-waveplate (center),radial/azimuth polarization beam intensity distribution after S-waveplate

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Custom spatially variable waveplates

We can fabricate custom spatially variable waveplates (half-wave or quarter-wave) for tailored polarization conversion and beam shaping. We can inscribe spatially vary-ing fast axis angle pattern according to your function. Various custom spatially vari-able waveplates examples are shown in fig. 2.3.3.

Features custom spatially variable fast axis and/or retardance patterns wavelength range from 400 nm to 2000 nm half-wave or quarter-wave converters available size from 1 mm to 20 mm transmission from 40% to 90% (* wavelength dependent)

Fig. 2.3.3. custom spatially variable waveplate photos in crosss polarized light

500 μm

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Bragg Gratings

Volume Bragg Gratings (VBG) are formed in fused silica using direct laser writing technology based on femtosecond Gauss-Bessel beams.

Features: Absolute diffraction efficiency up to 99% Refractive index modulation of up to 0.003 Up to 1000 lines/mm Thickness of the grating of up to few millimeters Custom shape and size of the grating is available on request

Fig. 2.3.4. Bragg grating model

Fig. 2.3.5. Bragg grating fabricated in fused silica substrate

Θm = ΘB Θdtƒ = ΘB

Transmited beam

Diffracted beamIncident beam

y

t

z

dn1 = 1 n2 = 1,46

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2.4. Beam Shaping Unit

Beam Shaping Unit is applied in laser systems for micromachining applications to create round or square laser spots with uniform intensity distribution.

The BSU-6000 is developed to operate in combination with customer’s scanning op-tics, but can also be offered as a complete system. It is based on refractive field map-ping beam shaper πShaper.

Output of the πShaper is imaged onto a workpiece by imaging optical system com-posed from an internal collimator and external lens, for example F-theta lens of the customer’s equipment.

Fig. 2.4.1. Example of beam shaping: Left: input laser beam, Right: final square spot.Final laser spot size and shape depend on customer‘s requirements

Fig. 2.4.2. Front and back side view Fig. 2.4.3. Side and top view

*All dimensions are in millimeters.

36,5

97

20025,5

50

206,5

50

250175

251

585

36,5

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20025,5

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Front (input) view

Side view

Back (output)

view

Top view

BSU-6000

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Requirements for the Customer‘s Laser

Wavelength 257-2050 nmAverage power up to 200 W CWPulse duration ns, ps, fsMode structure TEM00 or multimodeIntensity distribution Gaussian or similar

Optics

Input beam diameter 6.3 – 6.4 mmOptical axis height (from bottom) 50 mmFocal length of internal collimator 6000 mmBeam shaper model πShaper 6_6 (unit type dependent)Spot shape Depends on aperture shapeSpot size - depends on magnification of the com-

posed imaging system being defined as ratio of focal lengths of F-theta lens and internal collimator,- variable in case of Iris diaphragm

Mechanics

Dimensions (LxWxH) 585x251x97 mmInput aperture diameter 20 mmOutput aperture diameter 20 mmWeight < 6 kgAperture placement see figures 2.5.2, 2.5.3Mounting points see figures 2.5.2, 2.5.3

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BSU-8000

Beam Shaping Unit 8000 is intended to be applied in laser systems for various mi-cromachining applications to create round or square laser spots with uniform intensity distribution. BSU-8000 was developed by AdlOptica and technically implemented by Workshop of Photonics.

The BSU-8000 is developed to operate in combination with customer’s scanning op-tics and is based on refractive field mapping beam shaper πShaper.

Output of the πShaper is imaged onto a workpiece by imaging optical system com-posed from an internal optics and external lens, for example F-theta lens of the cus-tomer’s equipment.

Fig. 2.4.4. Intensity profiles a) Input TEM00 b) Output beam profile

Fig. 2.4.5. Bottom and side view of BSU-8000*All dimensions are in millimeters.

Output beam mirror mount. Can be rotater by 90°,so exit beam can be rotated up/down/left/right

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A principal optical scheme of BSU installation is demonstrated in Fig. 2.5.6. The mirrors, marked by letter M and M‘, are to be installed prior the installation of BSU. It is just to imagine how optical path should be prepared in advance. Mirrors M‘ are removed during the installation and replaced with the BSU.

Please consider that mirrors M1 and M2 before the enatrance of the BSU are neces-sary to allow proper alignement of the beam. Two mirrors M3 and M4 after the exit of BSU they are necessary for proper beam alignement to the scanner unit. The distance between a couple of mirrors should be at least 200 mm.

BSU installation

Fig. 2.4.6. A principal optical scheme of BSU installation

Specifications

Input and output aperture diameters 20 mmZoom Beam Expander 0.7x...1.3xOutput beam diameter from beam expander

4.5 mm

Beam shaper model πShaper 4.5_4.5_1064 (unit type dependant)Focal length of internal collimator 8000 mmPower losses <15% (losses due to the additional apertures

not included)Flattness of flat top >95% for TEM00 beam, M2<1.1, to be

evaluated additionally for M2>1.1Final spot diameter (on the focus plane of F-theta)

56±6 um (<10% variation)

Final spot diameter (on the focus plane of F-theta)

90±9 um (<10% variation)

Dimensions (LxWxH) Approximately: 690x400x100 mmDistance from BSU to scanning head 500-1000 mmWeight 20 kg

Additional components

Mount for fixing apertures Mechanical with fixing screws (M6)Fized size square aperture Diagonal 4.4 mm, different available on requestA set of fixed diameter round apertures (5 pieces):

Diameter 4,0-4,4 mm, with 0,1 mm step

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2.5. WOP module for cutting glass and sapphire

Technology specifications

Workshop of Photonics has developed a break through transparent material cutting technology, which enables:

Scribing tempered, non-tempered glass and sapphire Irregular shape cutting High process speed ≥ 200 mm/s High throughput and yield Low chipping <20 μm for most materials Easy breaking for non-tempered glass and self breaking for tempered glass Smooth side walls after breaking, Ra<1 μm No debris on back and front surface Single pass process for glass up to 1 mm thickness Already tested with high DOL glass from 0.4 mm to 1.3 mm thickness DOL layer from 10 μm to > 40 μm. High bending strength Easy adaptation for different glass types

Solutions for system integrators

Transparent material cutting module specifications:

Optimized for 1028 nm wavelength Sealed monolithic housing Integrated autofocus (AF) unit with 400 μm piezo axis for sample tilt compensa-tion

Integrated motorized linear axis with 15 mm travel, optional, eliminates the need of external Z axis

Optional external Machine vision unit (not present in picture below) Optional alignment module for adjustment Dimensions HxWxD: 315x369x102 mm

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Integration

For system integrators Workshop of Photonics offers easy to implement packages:

Optical module and technology licence Optical module, technology licence and suitable laser source

Standalone module mounting can be seen in the picture bellow:

As an alternative optical head mounted on dedicated source can be offered.

Mechanical stress free three point mounting with optional hard

points for easy exchange

Two optional laser beam inputs

1.

2.

3.

1. Detachable alignment unit (DAU) – for ad-justment and for servic-ing procedures (align-ment check). One DAU can be used for several modules

2. External Machine vi-sion module. Includes objective (from 1.5x magnification) with co-axial light source GigE camera

3. 400 μm piezo stage for AF and 15 mm motor-ized internal linear Z stage for adjusment be-tween different thick-ness glass

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Workshop of Photonics has developed a new state of the art glass and sapphire cutting technology to meet new challenges arising from new materials and requirements. Our technology enables dicing glass or sapphire from 30 μm to 1.3 mm (tested) thick with process speed from 100 to 1000 mm/s depending on specific requirements. Straight and curved cuts can be performed at the same step with same or similar parameters.

Processing steps for tempered glass:1. A flat sheet of glass has to be positioned under the laser beam in the approximate

beam focus distance.2. Depending on the thickness of glass, one or two passes per trajectory might be

needed.3. Surface position tracking is advised for large area samples. Hardware solution for

the surface tracking may be provided by Workshop of Photonics.4. Sheet of glass is removed from the machine. Two alternatives are possible for

cleaving:a. Initiation of self cleaving, by creating temperature gradient in the sample –

slightly heating or cooling one side of the sample (please watch the video on www.wophotonics.com).

b. Sample can be left for several minutes untill self-cleaving happens without initiation.

3. Technology

Fig. 3.1.1. Tempered glass 0.55 mm thickness,42 µm DOL. Top view

Fig. 3.1.2. Tempered glass 0.55 mm thickness,42 µm DOL. Side view

200 μm

3.1. WOP laser technology for cutting glass and sapphire

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Processing steps for non tempered glass and sapphire:1. A flat sheet of glass/sapphire has to be positioned under the laser beam in the

aproximate beam focus distance.2. Depending on the thickness of sample, one or two passes per trajectory might be

needed.3. Surface position tracking is advised for large area samples. Hardware solution for

the surface tracking may be provided by Workshop of Photonics.4. Since non tempered glass and sapphire do not have internal tension, cleaving does

not happen on itself and has to be initiated. This can be done mechanically (bend-ing sheet allong the scribing lines) or a different method might be developed.

Fig. 3.1.3. Sapphire 0.325 mm thickness.Top view

Fig. 3.1.4. Sapphire 0.1 mm thickness.Side view

Tested Glass and Sapphire Samples

Technology was tested on a variety of glass and sapphire samples provided by various suppliers. List of the samples successfully tested to date, are provided below.

Table 1. List of tempered glass samples tested

No. Sample brand Thickness, µm DOL, µm1. Not provided 550 302. Gorilla glass 550 423. Gorilla glass 700 424. Gorilla CS 700 235. Gorilla CS 800 236. Not provided 800 307. Gorilla glass 1100 108. Not provided 1300 309. Not provided 850 7

200 μm 50 μm

100 μm

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No. Sample brand Thickness, µm1. Schott 302. Schott 1003. Not provided 3004. Not provided 5205. Cornin Eagle glass 3006. Gorilla 7007. Gorilla 5508. Soda Lime glass 700

Table 3. List of sapphire samples tested

No. Sample brand Thickness, µm1. Crystaline sapphire 100-7602. Sapphire with ink layer (black, white) 4203. Sapphire with AR coatings 420

Processing parametersProcess is optimized for each type of glass/sapphire that is used. Processing window is quite wide and can be set up easily according to these parameters:

Straight and round cut trajectories Thickness of tempered glass: 0.5 – 1.3 mm DOL of tempered glass: 10 – 42 µm Thickness of non-tempered glass: 30 – 500 µm Thickness of sapphire: 100 – 760 µm Speed of cutting (tested): 200 mm/s Speed of cutting (extrapolated): 800 mm/s Cut surface roughness: Ra<1 µm

Different processing parameters might be developed for specific inquiries.

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3.2. Heat Sensitive Materials Scribing

Workshop of Photonics developed a special technology for heat sensitive material processing.

The fabrication comprises: No heat affected zones and melting layers Grooves of less than 15 µm widths and more than 25 µm depth No overshooting in intersections Better than 0.5 µm accuracy within 40 mm area Fabricating up to 9 samples without any operator interference Controlling the fabrication process for up to 24 hours long and maintaining

needed accuracy, compensating beam and mechanical drift within 0,5 µm

20 μm

Fig. 3.2.1. Top view of scribed ceramics

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3.3. Through Glass Via (TGV) Drilling

TGV – through glass vias is another example of industry driven development at Work-shop of Photonics. This technology is used for semiconductor applications to connect several layers of stacked microchips.

The new innovative beam positioning method was created by our engineers to achieve industrial quality requirements.

This technology is currently under development, current specifications is subject to change in the future.

Specifications

Thickness Material Hole diameter Elipticity Taper Speed100 µm glass 60 µm < 4 µm ~3 deg 0.25 s/hole50 µm glass 30 µm < 4 µm ~3 deg 0.25 s/hole

100 µm sapphire 60 µm < 5 µm ~ 3.5 deg 0.22 s/hole

20 μm 100 μm

Fig. 3.3.1. Matrix of holes in glass Fig. 3.3.2. Matrix of holes in sapphire

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Fig. 3.4.2

3.4. 3D Additive Manufacturing

3D additive manufacturing, in other words multiphoton polymerization (MPP) is a unique technology for 3D structuring of micron scale objects with nanometer precision co-developed with Vilnius University Laser Research Cent-er. Femtosecond laser beam is focused inside a drop of sol-gel or other types of photoresist polymer and desired pattern is “written” precisely point–by-point. Then, the unsolidified remainder of the photoresist is washed away leaving only the fabricated microstructures on the substrate (Fig. 3.4.2).

Features: 100 nm – 10 µm writing resolution Medium cost per sample Variety of polymers Complex 3D objects

5 μm

Fig. 3.4.1

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The SCA laser automation software product family provides speed, visibility and ef-ficiency to multiphoton polymerization operations and other laser micromachining tasks. The software is distinguished among other existing laser software solutions by the key working principle – it controls positioning stages by directly addressing the command libraries of the positioning stages software (no machine code conversion). Structures of any geometry can be fabricated directly from CAD file. There are no limitations for object shape or direct writing geometry, except those limited by obvi-ous laws of physics.

Photoresist Polymer Materials Variety of photoresist materials with

required features can be chosen No structural distortions Certain wavelength absorption Refractive index matching

Precision and Controllable Self-Polym-erization

Standard direct writing is able to make repeatable structures as small as 100 nm, though by employing self-polymerization effect, the smallest lines can be around 20 nm. This effect occurs when certain distance between polymerized structure walls is kept, so self-polymerizing structures can be controlled, at least to some extent.

Repeatability

Reliable and multifunctional software SCA Professor ensures fast preparation, stable workflow. 3D lithography is related to huge amounts of data, which has to be trans-mitted between computer and positioning controllers. Many systems crash because of poor software adaptation to these specific tasks. SCA professor splits the data in portions to deliver them safely and timely to the controllers. Moreover, identical structures can be fabricated by direct laser writing process but in order to save time and work for large area patterning stamping technique can be used.

Main Applications: Microoptics Photonic crystals Regenerative medicine

< 90 nm

10 μm2 μm

Fig. 3.4.4

Fig. 3.4.5 Fig. 3.4.6

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Fabrication examples

1. Conventional minimized optical components

2. Free form 3D elements

3. Arbitrary shape arrays of the µ - optical components with 100 % fill factor

4. Complex shaped, multi-functional and integrated μ-optics in a single fabrication procedure.

Lenses

Spiral phase plates

Prisms

Segmented phase plates

Gratings

Fresnel lenses fraxicons

Axicons

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Micromachining Examples

Processing of solar cells

Applications: Front contact formation Back contact formation

Edge isolation for solar cells

Selective dielectric layers removal for solar cells

For novel emitter side metalization technologies

For PERC technology

Laser marking of solar cells

10 μm

50 μm

30 μm

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Nano ripples Up to 200 nm ripple period fabricated using ultra-short

laser pulses Individual nano-feature size on ripples: 10 – 50 nm Controlled period, duty cycle and aspect ratio of the

ripples

Applications: Detection of materials with increased sensitivity using

surface-enhanced Raman scattering (SERS) Bio-sensing, water contamination monitoring, explo-

sive detection etc.

Metal micromachining 3D structures formed on steel surface High precision and surface smoothness achieved

Cast iron ablation Surface texturing with micro holes and grooves Minimum heat affected zone

Application: Friction reduction between moving metal parts

Marking of transparent materials bulk Marking made inside a bulk of contact lens, preserving

surface of lens and distortions Exact positioning of markings – 3D text format

Applications: Product counterfeit protection Development of novel products

1 μm

200 μm

100 μm

Developed in cooperation with Swinburne University,

Australia

100 μm

32

Diamond cutting Low carbonization No HAZ Low material loss

Applications: Diamond sheet cutting Diamond texturing/patterning

Ablation of PCD (polycrystalline diamond) Ablated circle crater on the surface of PCD Smooth and even bottom of the crater

Application: Component of PCD cutting tools

Steel foil μ-drilling No melting Micron diameter

Applications: Filters Functional surfaces

100 μm

100 μm

10 μm

Micro channel formation Wide range of materials – from glass to polymers

Applications: Microfluidic sensors Waveguides

33

Datamatrix Data inscribed on a glass surface Extremely small individual elements, up to 5 µm

in size

Application: Product marking

100 μm

Mask for beam splitter pattern deposition Borosillicate glass 150 um thickness ~900 holes per mask Mask diameter 25,4mm

Application: Selective coating

Glass tube drilling Controlled damage and depth

Application: tissue biopsy equipment

20 μm

15 μm

Marking inside a bulk of transparent material Colorful structures due to small pixel size Surface not affected Very small or no cracks near markings Low influence on strength of the substrate

100 μm

Optical fiber GlassSapphire

34

Glass holes Various hole sizes with routine tapper angle better than

5 deg Minimal debris around the edges of holes

Application: Microfluidics

Top view

Cross-section

100 μm

Stent cutting Holes in stent wall, cross-section view Polymer stent No heat effect, no debris Minimal taper effect

Application: Vascular surgery

Fuel Nozzle drilling: Special steel Controllable taper angle Variable geometry

Application: Fuel delivery systems

100 μm

100 μm

35

Marking, patterning capabilities: Smallest spots up to 3 µm in width Micron level positioning No heat effect

Metal

Hair

Texturized sapphire surface Micron resolution Large area processing Single pulses used to form craters on the surface

Applications: Better light extraction in LED Semiconductor structure growth

30 μm

Wood marking No heat effect, no signs of burning

Applications: Laser marking processes in highly flammable environ-

ments Decoration Counterfeit protection

10 μm2 μm

5 μm

36

100 μm

50 μm50 μm

Titan coating selective ablation

Apperture array fabrication Gold layer removal without dam-age to MgO substrate – Au layer

removal without damaging

Chrome ablation for beam shaping

Amplitude grating formation

Chrome ablation from glass substrate

Selective metal coating ablation (removal) Selective ablation of metal coatings from various sur-

faces Depth and geometry of ablation may vary

Applications: Lithography mask production Beam shaping elements Optical apertures Other

Optical fiber drilled to the middle Diameter from <10 μm Various hole profiles possible Depth and angle control

Applications: Optical fiber sensors Material science

37

Optical fiber scattering No impact on fiber strength No surface damage Even light dispersion

Applications: Medical fibers Oncology

Optical fiber lensed using MPP technique Matching refractive index Shape flexibility Resolution from 100 nm to 20 μm

Applications: Medical fibers Fiber collimators

100 μm

200 μm

Serial production of micro-parts Submicron precision micro parts made of polycarbon-

ate/polypropylene/poly(ethylene terephthalate) Minimal or no signs of heat effected deformation Excellent cut surface quality, sub-micron precision of

shape High speed laser processing

Applications: Consumer electronics MEMS systems

38

Glass micro-hole drilling (50/25 µm diameter) Glass 320 µm thick Hole entry diameter: 50 µm Hole exit diameter: 25 µm High hole quality

100 μm

100 μm

51.3 μm

25.1 μm

39

Partners

COMMERCIAL PARTNERS

Our solutions often incorporate products and know-how of Lithuanian and foreign la-ser companies:

ACADEMIC PARTNERS

The company strives to bring new inventions from academia into market. Therefore, we invest time and effort into building mutually beneficial academic partnerships:

Vilnius University, Lithuania: micromachining research and applications. Kaunas University of Technology, Lithuania: coatings, lithography and microfabrication. Swinburne University of Technology, Australia: SERS sensors for Raman spectroscopy

development. University of Southampton, United Kingdom: development of special optics. University of Insubria, Italy: femtosecond micromachining using non-Gaussian beams. Tampere University of Technology, Finland: joint development of OPSL yellow laser.

Mokslininkų st. 6A tel. +370 5 272 57 38 info@wophotonics.com 08412 Vilnius, Lithuania fax +370 5 272 37 04 www.wophotonics.com

Altechna R&D

Participation in Exhibitions

13-18 February 2016, San Francisco, USA

15-17 March, 2016, Shanghai, China

22-25 June, 2015, Munchen, Germany. Booth B3.405