Laser Solutions Short Courses · 1,5kW CO 2, 120W YAG Beam Radius 11146 NO STANDARD Beam Position 11146 - M² 11146 - 49 Pointing-Stability 11670 - Polarization 12005 - There is an

Laser Solutions Short Courses

Short Course #1 Introduction to Laser Beam Power,

Energy and Beam Profiling

Larry Green Course Instructor

Monday, November 2 1:30PM

Room: Narcissus/Orange

16.09.2009

1

ICALEO 2009

Short Course:

1

Introduction to Beam Profiling

Volker Brandl- Primes GmbHLarry Green- Ophir-Spiricon, Inc.

Objectives

• Fundamental beam parameters describing the performance of a laserA brief look at ISO 11554 and ISO 11146

• Detection methods and measurement strategies for critical beam parameters on lasers from from 1 W to 20 kW

• Learning how to interpret what you see in the measurements and the corresponding problem in the laser / beam path / focusing optics

2

corresponding problem in the laser / beam path / focusing optics

• Typical applications of laser beam analysis in industrial processes and process development

• Future developments in laser beam diagnostics

Course Outline

• Define Concept of Mode Quality• Show What Happens in Process When Mode

Changes• Detailed Introduction to Beam Profiling

Instrumentation

3

Instrumentation• Examples of How to Diagnose Processing

Problems• New Profiling Techniques

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To be Effective-What One Must Know

1. The Process Window

2. Beam Theory & ISO 11146

3. Measuring & Quality-Assurance

4. Some Real Life Examples

4

Why do I Need to Measure my Laser?

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If You Cannot Measure it, You Cannot Control it

“If you can't describe what you are doing as a process, you don't know what you're doing.”

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W. Edwards Deming (1900-1993)

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Successful Use of Beam Diagnostics can Increase Profitability

• Less Waste

• Higher Production Rates

• Lower cost per part produced

F t S t ti

7

• Faster Set up time

• More Consistency of Process

If Overlap area: Process:

Is zero stops

Is small unstable

Tolerance for fur-

Process Window Diagram

axisspeed

focusposition

8

focusdiameter

ther interference

Process efficiency

Speed

Parts out oftolerance

laserpower

If overlap area process

Is large stable

Tolerance forinterference

axisspeed

focusposition

Process Window Improved

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Process efficiency

Speed

Parts out oftolerance

focusdiameter

laserpower

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quality assurance

pre-process-diagnosticsof parts

machine & laserparameters

simultaneous /online-diagnostics

post-process-diagnostics

- seam position

Quality Assurance- The Goal

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- part orientation- seam/kerforientation

- shape detection- seam/kerf width

- beam positionand diameter

- laser power- power density- power densitydistribution

- plasma

- UV/IR stray light- backscattering- melt pool- temperatures- shape control- position control

- hardness profile- electro-magneticmeasurements

- x-ray analysis- ultrasonic- visual jointfailures

- destructiveanalysis

Quality Assurance

quality assurance



simultaneous /online-diagnostics

post-process-diagnostics

- seam position

11





- plasma

- UV/IR stray light- backscattering- melt pool- temperatures- shape control- position control

- hardness profile- electro-magneticmeasurements

- x-ray analysis- ultrasonic- visual jointfailures

- destructiveanalysis

quality assurance

measuring and d ti

Quality Assurance



12

documenting errors

replaced by

error prevention





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• Qualification of beam sources, machines and processes

• Process parameter verification before or during processing

• First-time installation of a laser system or after service

• When moving a system to a new location

When to do Beam Diagnostics?

13

• When moving a system to a new location

• Error analysis

• Optimization of a system, optical components or to improve processing speed

Introduction to Laser Beam Quality

• What IS laser beam quality?

• How do we define it?

• How do we measure it?

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How do we measure it?

Laser Beam Quality Defined

• LASER BEAM QUALITY- DEFINITION• Ability of the laser to deliver proper energy to the

target (work surface) • Proper spatial energy distribution of the beam• Right time (stability of the output- Temporal profile)

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Right time (stability of the output Temporal profile)• Right place (location of work surface)

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Spatial Beam Profiling is Universally Understood Method for Determining Beam Quality

• Combines All Variables That Create a Beam Into One, Easy-to-Understand Picture

• Intuitive Appraisal of Beam Mode Quality

Basic Advantage of Spatial Beam Profiling

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• Intuitive Appraisal of Beam Mode Quality

• Quantitative Calculations

• Powerful Diagnostic Tool

How Do We Measure Laser Performance?

Old-Technology Measurements are no longer

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are no longer adequate.

Examples of Poor Beam Quality

• Spatial Distribution due to various laser failures/faults– Poor Tuning/Alignment in Laser Cavity

– Broken Rods (YAG)

Lamp Deterioration (YAG)

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– Lamp Deterioration (YAG)

– Water Supply Temperature Variations

– Diode Failures (DPSS)

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Example of Identifiable Problems

• YAG laser with cracked rod, energy no longer in center of beam

• Cavity mirror misadjusted

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y jshows skewed profile

Improper Mirror Adjustment on CO2 Laser

Adjustment of mirrors can be done in real time for best beam quality

20

Before Final Adjustment After Final Adjustment

Examples of Poor Energy Stability

• Overshoot/Undershoot of beam power

• Instability due to back reflection from work surface

• Instability of raw beam diameter during operation

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• Instability of raw beam diameter during operation

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Stability on Startup Test 1

Stability on Startup

335.00

340.00

345.00

)

17.20

17.40

17.60

m)

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315.00

320.00

325.00

330.00

335.00

0.00 1.00 2.00 3.00 4.00 5.00 6.00

Time (seconds)

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we

r (W

att

s)

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16.20

16.40

16.60

16.80

17.00

Dia

me

ter

( m

m

Stability on Startup Test 2

Stability on Startup 2 kW

2080

2100

2120

) 30

30.2

30.4

)

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1960

1980

2000

2020

2040

2060

0 1 2 3 4

Time (seconds)

Po

wer

(Wat

ts)

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29.2

29.4

29.6

29.8

30

Dia

met

er (

mm

)

Energy Variation - No Back Reflection

Powder Flow Energy vs. Time

600.00700.00

Wa

tts

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0.00100.00200.00300.00400.00500.00

1 9

17

25

33

41

49

57

65

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81

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Time-Seconds

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r E

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rgy

, W

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Energy Variation from Back Reflection

Pre-Spread Powder Energy vs Time

1000 00

1200.00

1400.00

W)

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0.00

200.00

400.00

600.00

800.00

1000.00

0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00 180.00

Time (S)

Las

er p

ow

er (

W

Output Coupling Mirror Degradation

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Beam Width of an 8 kW CO2 laser (Tailored Blank machine) over 5 months time

Contaminants

• Presence of Hydrocarbons in the beam path distort the beam

• Any Contaminant will affect the beam mode qualityDistortions will cause process problems and be

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• Distortions will cause process problems and be almost impossible to identify without in-line monitoring

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Some Causes of Poor Pointing Stability

• Heating/lensing of delivery optics

• Purge Gas contamination

• Mechanical vibrations in the plant

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Mechanical vibrations in the plant

• Temperature Variations of Chiller

hot air lens

thermoelastic coating deformationcreates thermal layer lens

ideal real

Thermal focusing on a flat surface due to residual absorption(or: what happens when an output coupling mirror degrades?)

The Enemy: Thermal deformation of optics

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coating

substrate

thermoelastic substrate deformation

creates thermal layer lens

Beam is Focused!Beam is Collimated!

Transient Response

6kW CO2 laser welding 16 welds in 12 seconds

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Initial Beam (shutter opened) Beam after only 0.25 seconds

Beam width shrinks by almost 10 percent during process

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Transient Response-Tells all

• 3D images show dramatic profile changes in process.

• 2D images show intensity changes.

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Pointing Stability

• Graphical information display

• Changes are easy to identify

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Spatial Beam Profiling

• Spatial profile incorporates ALL variables that make a laser beam into one easy-to-interpret image

• Real-time images show transient response

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Real time images show transient response

• Calculations remove all subjectivity

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Can You Tell Which Beam is Good?

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Current Technology for Beam Profiling

• Measure Critical Beam Parameters

• Are Relatively Easy to Understand and Use

• Can be Permanently Mounted or are Portable

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Spatial Profilers

• Calculate beam parameters– Width– Energy– Location of Centroid/Peak

Elli ti it

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– Ellipticity– Standard beam shapes (“Top Hat”, Gaussian)

• Display beam profiles

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Temporal Profile Monitors Shaped Pulses

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Ophir-Spiricon, Inc.

Pointing Stability Measurements

• Computed from Beam Profiler Measurements

• Exportable data to Process controllers

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Process controllers

“Historical” 1/e2 Beam Diameter

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“Historical” 1/e2 Beam Diameter

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“Historical” 86% Beam Diameter

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“Historical” 86% Beam Diameter

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“Historical” Knife Edge Beam Diameter

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“Historical” Knife Edge Beam Diameter

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“Second Order Moment” Beam Diameter (D4σ)

Diameter definition derived from variance in statistics

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Propagation

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General propagation lawClear definition of beam propagation parameters d0, z0, zR,M2

This is why ISO 11146 is based on the 2nd order moment beam diameter definition.

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Propagation law

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Laser Parameters and Instruments

Quantity• Power• Power Loss in the Beam Guiding System

• Power Density Distribution in the Raw Beam

• Beam Position on all Mirrors / Optical Elements

• Pointing Stability (Over Power)• Beam Waist Position and Diameter (Over

Power)

InstrumentPower Meter

2D/3D Beam Analyzer With Suitable Aperture

48

• Power Density Distribution in the Focused Beam

• Focus Position in Relation to the Optics (Tool Center Point)

• Focus Shift With Power

• Polarization State

3D Caustic Analyzer (M2 or K)

Polarization Sensor

All measurements should be performed at full operating power or over a range of powers.Traditional YAG lasers usually have a fiber beam guiding system and high transmission optics, resulting in less focus shift / pointing shift. This might change with the latest solid state laser generation, as power density on optics increases rapidly.

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DIN EN ISO STANDARDS

Parameter ISO Standard National Standard

Power 11554 available1,5kW CO2, 120W YAG

Beam Radius 11146 NO STANDARD

Beam Position 11146 -

M² 11146 -

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Pointing-Stability 11670 -

Polarization 12005 -

There is an ISO specification for testing a CO2 laser, (DIN EN ISO 15616, part 1-3:2003).

If you want to calibrate an instrument, you need a national standard against which it can be compared. No national standard means no calibration available. What you can do in that case is to verify the instrument against an internal standard of the manufacturer.

Spatial Profiling Instrumentation

• Rotating Slits

• Spinning Wires/Needles

• Camera-Based

Types of Spatial Profiling Instrumentation

50

Camera Based

Rotating Slit Measurement

• Narrow (micron-scale) slits rotate in front of beam

• Direct sampled energy to single element detector

• Mostly for low power applications

51

• Generally a lab instrument

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Mechanical Image Scanning

• Spinning Knife-edge Sapphire Slit system

• Limited to about 1W

• Limited to 3 mm beam width

52

• Limited to 3-4 Hz

Image courtesy of DATARAY, Inc.

Spinning Wire/Needle Measurement

• Uses a micron-sized pinhole at the end of hollow wire• Uses micron-sized mirror at end of needle• Directs small portion of reflected energy to single element

detector• Composite image takes from 2 10 seconds per image

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• Composite image takes from 2-10 seconds per image• Can measure unfocused and focused beams

Mechanically Scanning Instrument

The beam is scanned track by track by a fast rotating measuring tip

54

Applications: CO2-, YAG-, fiber-, disk-, diode-laser, mostly CW, high power densities possible, focused laser beam or raw beam. Many pulsed systems accessible via trigger.

RotatingMeasuring Tip

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Rotating Needle Principle

• ~10 um Pinhole in Tip

• Reflects Part of Energy to Mirror at Hub

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• Stepper Motor Moves Entire Assembly Through Beam

Image courtesy of PROMETEK, GmbH

Rotating Needle Image

• 10 seconds to complete image

• Not real-time

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• White lines where laser was ‘off’ shows discontinuities in image

Oscillating Wire Systems

Wire passes through beam

Reflected energy is detected

Gives line drawing of x and y beam profile

Simple set up and operation

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Very basic information

Very easy to use

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Camera-Based Measurement

• Detector array in camera images entire beam at one time

• Different cameras for different wavelength beams

• Different sampling schemes depending on total power

• Generally for unfocused beams, but can be used for many

58

y yfocused beams

Industrial Beam Profiling Instruments

• For 400-1100 nm Lasers

• Power up to 4 kW

• Integrated systems– Some measure power and

temporal profile as well as Beam Profile

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Industrial Beam Profiling Instrument

• Now for high power CO2

as well as Near IR applications– Up to 48 mm diameter

beams

60

beams

– Up to 8 kW continuous power

– Can be permanently installed for on-line beam monitoring

• Totally transparent to the process

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High Power In-Line Monitor

• Uses Off-the-Shelf Components

• Main Beam reflects off only flat surfaces

• High and Low P S ti

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Power Sections Separated for safety

Portable CO2 Analyzer

• Standalone

• Up to 8 kW

• 48mm CA

• Real-Time Imaging

• Can be combined with Power Meter for delivered

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power readings

New Low-Cost Mode Check System

•ELIMINATES MODE BURNS!

•Produces NO vapors or carcinogens

•Simple, Low-Cost System

•Can be set up in minutes

N li t!

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•No alignment!

•Works with CO2 lasers from 500W to 5 kW, and beam diameters to 37 mm

•New software gives real-time imaging in 2D AND 3D

•Portable, no water cooling!

•Can be used with Laptop computer

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Sample Screen from ModeCheck

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3D Image Can be Inverted to look like

Conventional Mode Burn

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Sampling Techniques

• Regardless of Type of Laser , power level or application, one diagram describes sampling

• Separated into basic blocks, easy to decide best

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p , yinstrument for your application

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How to Analyze a Laser Beam

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LASER BEAM ATTENUATE SIZE DETECT ANALYZE


150 kW CO2 Laser- How to Analyze This?Beam Diameter is 100-125 mm!!!

How to Analyze a Laser Beam

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High Power CO2 Profiling Instruments

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Advantages:

• intuitive handling

• quick use

• Low Cost

Disadvantages:

• possible contamination of optics

Primitive Measurement Tool: Mode Burns

70

• ventilation is required due to carcinogenic fumes

• no numeric values or computing

• interpretation of results. Usually be user dependant results

• no automation

Advantages:

• Quantitative Numeric values

(operator independent)

• No contamination

• More information available

Electronic Devices with PC Interface

Measurement Tools

Focused Beam Unfocused Beam

Instruments for

71

• More information available

• Automation possible

Disadvantages:

• More costly

• Time consuming

• Evaluation of results requires know-how

Beam Propagation Polarization

(Similar systems offered by ALS, Coherent, DataRay, Hamamatsu, Ophir-Spiricon, Photon, PRIMES, Prometec and about 28 other Vendors)

LOW END HIGH END

up to 100 kW; wavelength UV, VIS, NIR, FIR

General measuring principles for high power:(1) P P b (h dh ld) (2) Th il (3) C l i t

Laser Power/Energy Measurements

handheld devices Water or air-cooled instruments, probably with detachable head

computerized, self-calibrating / verifying, high power densities

72

(1) Power Probe (handheld), (2) Thermopile, (3) Calorimeter

Fig

ure is p

rop

erty of G

entec eo

water

laser

power is product of mass-flow, heat capacity, temperature difference

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Power Measurement

• Determine Your Power Range

• Specify your Wavelength

• Choose a Suitable Smart Head and Display for your application

73

beam path

recollimator

Typical Camera Based Instruments

CCD / CMOSCAMERA (sensor board)

74

switchable attenuator

Applications: lasers: YAG, fiber, disk, diode (CO2

possible, but demanding due to beam splitter and IR area sensor), pulsed and CW, high power densities possible, focused laser beam or raw beam. Sophisticated attenuation and camera electronics is vital for reliable results.

M2 Measurement Devices

• Moving Mirrors Change beam Path to Stationary Camera

• Portable or Bench Mount

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• M2 in as little as 45 seconds!

• TRUE ISO 11146 calculation

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Simple Beam Profiling Checklist

What is the Average Power of the laser?

What is the Wavelength of the laser?

What is the Width of the laser beam?

Pulsed or CW?

76

What quantitative information do I need to characterize the beam? Beam width, shape, position, pointing stability)

What You See-What it Means

• Learn to identify problems from characteristic profiles

• Some commonality amongst applications

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Some commonality amongst applications

• Your application my be unique– Personal training may be useful

Real Time Tuning Example

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Applications:

• Limited only by your imagination

• Seek help EARLY in the design phase

• Almost any beam can be imaged

– Any Size

– Any Wavelength

Any Power

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– Any Power

– Pulsed or CW

Parameters: Power Density

If beam diameter changes, and other parameters remain the same (i.e. M2)Welding depth as a function of power density

(as a function of raw beam diameter)

@ 5 kW und Vs = 40m/min

1 11.21.31.41.51.61.71.8

80

results in focus diameter change

00.10.20.30.40.50.60.70.80.9

11.1

1000 10000 100000 1000000 10000000 100000000 1000000000

D = 30 mm (constant), M2 varied

Parameters: Focus Diameter

500

600

700

800

ete

r /

µm

Focus diameter as a function of M2

81

d0 ≥ 157,9 µm

f = 300mm0

100

200

300

400

500

0 1 2 3 4 5 6

Fo

cus

diam

e

M2 = 1/k

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ldin

g D

ep

th [

a.u

.]

Th

res

ho

ld

Tra

ns

ien

t R

eg

ion

Heat DiffusionWelding

Deep PenetrationWelding

Unstable Region

• Laser Power PL

• Spot Radius rF

• Beam Quality M2

• Wavelength l

• Welding Speed vs

• Power Density I = P /pr 2

Laser Beam Parameters and Process

Example: Welding

82

We

l

Process Parameter: I • rF / vs [a.u.]

T I = PL/prF2

• Line Energy Es= PL/ vs

• Rayleigh LengthzRF = prF

2/lM2

• Seam Cross Section is proportional to Line Energy• Seam Width is proportional to the Beam Diameter on Workpiece• z-Positioning Tolerance is proportional to Rayleigh Length

se

r P

ow

er

[a.u

.]

• Laser Power PL

• Spot Radius rF

• Beam Quality M2

• Wavelength l

• Workpiece Thickness ts

• Cutting Speed v

Laser Beam Parameters and Process

Example: Cutting with Inert Gas

83

La

s

Process Parameter: ts • rF • vc [a.u.]

• Cutting Speed vc

• Rayleigh LengthzRF = prF

2/lM2

• Kerf Width is proportional to the Beam Diameter on Workpiece• Positioning Tolerance is proportional to Rayleigh Length

Linear Polarized Beam

A narrow,parallel, 90° edge

B rough, tilted cutting kerf

C wide,rough, 90° edge

Polarization Effects with Laser Cutting

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Polarization of the laser beam influences the amount of power that is absorbed in the cutting kerf, either on the cutting front or on the side surfaces. Therefore normally circular polarization is applied for cutting. The quality and long term performance of the polarization elements determine the cut quality.

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Clean/new mirror at 7kW laser power

Example: Contaminated Beam Bender

2D raw beam (after beam guide) + 3D caustic (in focus) measurement identify contaminated focusing mirror

85

Error is invisible at low power / in adjustment mode of the machine, very high process failure rate.

Contaminated mirror at 7kW laser power

Example: Focus Shift

po

we

r

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Focus Shift of 6.5mm

high power

z = 11.97mm

z = 18.50mm

low power

z-a

xis

Distance of the intensity maxima of a twin-spot focus

CO2 twin-spot, parabolic mirror.

Decreasing spot distance from left to right.

Example: Twin-Spot Welding

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Control of overlap / distance between two foci for welding applications with twin spot-optics

Nd:YAGCO2

Example: Twin-Spot Welding

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0,79 mm

Alignment of a triple spot Nd:YAG laser, three fibers.

Example: Triple Spot

89

Typical user questions:

(1) We are operating two welding machines with a Nd:YAG laser and fiber coupling. Why do the focusing heads have different temperatures? I don‘t see a real difference in my online diagnostics.

(2) Why are processing speeds significantly different for identical machines?

QA Questions

90

(3) We have a running system here in headquarters, and will expand/move to a new location. How can we transfer the “right” parameters from one machine/location to the next?

(4) My process stopped. Is it the laser or the material? We require redundancy.

Tools: Beam Profiler/ M2 Measurement plus Power Measurement

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Example: Collimating Optics

91

Results:Outside the focal plane, an intensity minimum is visible.This indicates either a particle blocking the beam path, or an erroneous optics, probably in the focusing head. The fiber end (=image in focal plane) is fine!


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Results:With increasing power, the phenomenon increases, too.The temperature of the focusing head increases noticeably due to absorption on the inside.

Inspection of:Fiber output couplerCollimating lensFocusing lens

On the collimating lens:


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lens:3 burns B,C,D1 crack A (main failure)

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The collimating lens had to be replaced.

The measurements should include the full caustic, not just the focal plane.

At low power levels, the problem was NOT visible.From 2,500 W and higher, the crack clearly generated a minimum in the power density distribution


94

minimum in the power density distribution.

Only an instrument that allowed measurements at full operating power made it possible to do the failure analysis quick and efficiently.

Example: Power Loss in Beam Guiding System

A BChange of mirror of the beam guiding system Change of output window and output coupler of laser

Service intervals for mirror exchange can be timed according to requirements

95

01-TWB-05-ergebnis monitor dissipation energy

% Power Loss Limit Power Loss (15%)

all mirrors1st mirror1st mirror

1st mirror

focus mirror

3D Caustic Information

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Simultaneous information on: focus radius, beam propagation factor, focal position, power density distribution, focus symmetry / astigmatism, raw beam diameter, status of beam guiding system

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Result:A “false” focus was found at z = 16,54 mm

A closer look reveals:

Example: Astigmatism

A common problem of parabolic focussing mirrors

97

Z(x) = 17,76 mm

Z(y) = 14,95 [mm]

As the beam hits the focusing mirror at an angle, there are 2 different foci for x,y direction at z(x) and z(y).

minimum x

min

imu

m y

Location of Focus Varies with Divergence

Focus Position for Converging beam

Focus Position for Diverging beam

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Focus Position for collimated beam

M2 System Shows Different Beam Profiles! (Which is the right one for your Application?)

Near Field Far Field

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Focus

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Focused Beam Profiles- Essential to Process Control

■ Beam is nearly Top-Hat

■ Energy is equally distributed across beam

10 W YAG at Focus

100

Same Beam only 250 µm into Far Field • Beam shape no

longer Top-Hat

• Peak in center of beam appears


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Attenuation: Key to Sampling Focused Spots

Passive

Can Handle


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Low to Medium Power

Polarization Corrected


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Direct Imaging of Focused Spot (190-1100nm)

FireWire or USB II Camera

Uses Known Technology

Each Wedge Reduces 20X

Direct Measurement of Focused Spot

Used on CW AND Pulsed


103

Used on CW AND Pulsed Lasers

For Focal Lengths >100mm

For 190-1100nm Lasers

Photo Courtesy of Ophir-Spiricon, Inc.

Negative Lens Translates the Focal Point


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And Enlarges the Beam


New Device for Shorter Focal Length Lenses

Distance from 1st optic to focal plane less than

68 mm


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68 mm

Photo courtesy of Ophir-Spiricon, Inc.

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CO2 Lasers Present Different Challenges

Needs Pyroelectric Array

Can Detect THz

Real Time imaging

Robust

UNCOOLED Detector


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UNCOOLED Detector


CO2 Array Pixel Spacing

• 100 um pixel spacing limits smallest spot size

• Can be overcome by using imaging optics to enlarge beam


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Imaging CO2 Microspots with Optics

10, 20 or 30X Enlarging Optic

Images in free space

Attaches directly to Pyrocam III

O ti Mid IR


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Optics are Mid IR Transparent

Operating range from 8-12 µm

II-VI Inc.

Photo Courtesy II-VI, Inc.

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Comparison of 121 um CO2 laser spot

With Enlarging Optic


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Without Enlarging Optic

Example 2: Focused Spot Profiling:How to change the Beam Profile when needed

150 W YAG laser, 150 mm Focal Length, ~350 µm focused spot


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2D & 3D Images at Focus. Beam is not Top Hat

Example 2: Focused Spot Profiling-Successful Beam Shape Modification

150 W YAG laser, 150 mm Focal Length, ~350 µm focused spot


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2D & 3D Images at Focus. New optics make beam almost perfect Top Hat

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Example 3 of Focused Spot Profiling

10 W Excimer laser, 15X25 mm masked spot


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2D & 3D Images before tuning. Beam has over 30 % irradiance variaton

Example 3: Focused Spot Profiling

10 W Excimer laser, 15X25 mm masked spot


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2D & 3D Images after tuning. Beam is now almost perfectly top hat


4 kW Diode laser, 0.5mm X 12.5 mm focused spot


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Beam is imaged from scattering surface at full power. By adjusting power supplies, beam has now only 8% variation (reduced from 19%)

Federal Mogul, Inc.

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4 kW CO2 laser, 250 mm focal length mirror, 300 µm focused spot


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Beam is imaged using CO2 attenuator at full power. Hot spot is clearly seen.

Future Developments

• Higher Power Measurements

• Smaller Beam Imaging

• In-line Continuous Monitoring

• THz measurements

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THz measurements

• Lower cost solutions

New Products- Process Monitoring

• Low to Medium Power on-line Multi-purpose Beam Monitor– Spatial Profile

– Power

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– Temporal Profile

• Transparent to Process– Does not interfere with

process beam

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Machine-Integrated Systems

• Combined measurement of – Tool Centerpoint (TCP)

– Focus Geometry

– Power

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Power

• Integrated machine interface (SPC)

• For rough environments

HP-MSMi

• State of the art for industrial production with high power lasers / welding

• Consequently built for

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• Consequently built for maximum reproducibility

• Beam geometry out of fiber and at the workpiece

• Robust and self diagnostic functions

Summary

While Beam diagnostics used to be a tool of the developers of laser sources, nowadays it is becoming increasingly important as a part of service, incoming inspection, quality assurance and process control.It is used to control costs.

It is a unique tool providing information that is otherwise inaccessible, like the status of the laser source, the true tool center point, the status of the beam guiding system, and the identity of predefined process parameters (like the power density at the point of interaction with the

i l) i h h f l hi

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material) with the current status of a laser machine.

Our feedback indicates that performance / efficiency increases or up-time increases in the range of 5-20% are common after beam diagnostics is introduced.

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Acknowledgements

Thanks to Dr. B. Eppich, Ferdinand-Braun-Institut, for permission to use part of his presentation ‚Standardization of laser beam parameters’ at the PRIMES Workshop on Sep 14th, 2006.

Thanks to Dr. O. Märten, MOC, and Dipl.-Ing. Klaus Hänsel,

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gHyperbel Laser Technology, for providing information and images.

Thanks also to the vendors who provided photos and descriptions of their instrumentation

Summary: Beam Profiling…

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Brings “illumination” to laser processing!

Thank You for Your Attention

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ICALEO® 2009 Laser Solutions Short Course Evaluation

Course #1: Introduction to Laser Beam Power, Energy and Beam Profiling Course Instructor: Larry Green Please rate the following: (circle) Very Course Excellent Good Good Fair Poor Overall Course 5 4 3 2 1 Course Instructor 5 4 3 2 1 Presentation of material 5 4 3 2 1 Organization of material 5 4 3 2 1 Course well paced 5 4 3 2 1 Would you recommend this course to others in your profession? yes no

What was the strongest feature of the course? What was not covered that you felt should have been covered (if anything)? What would you like to hear more about next time? What was covered that left an impression/impact on you? Suggestions & Comments (for this course or courses you would like in the future): Name: (optional)

Please Use Reverse Side for Additional Comments.

Please return evaluation form to the Registration Desk by Thursday afternoon

or fax 407.380.5588 to LIA upon your return home.

THANK YOU!

Documents

Laser Solutions Short Courses · 1,5kW CO 2, 120W YAG Beam Radius 11146 NO STANDARD Beam Position 11146 - M² 11146 - 49 Pointing-Stability 11670 - Polarization 12005 - There is an