Laser Focus World Webinar - Ophir Optronics Focus World Webinar The Importance of Electronic CO 2...

Laser Focus World Webinar

The Importance of Electronic CO2 Laser System Measurements

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Industrial CO2 Laser System Measurements

Why does someone go to the doctor: • Proactive Health Approach • Reactive Health Approach What Happens? • Tests (measurements) Are Taken • Diagnosis Given Maintaining a CO2 Laser is the Same Thing!

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Topics:

• CO2 Laser Beam Generation • How are CO2 Lasers Being Used? • Laser Measurement Equipment

• Past and Present • Measurements Taken on CO2 Lasers • Why These Measurements Are Important

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CO2 Laser:

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Typical CO2 Laser System Uses

Uses for CO2 Lasers: Cutting Welding Cladding Marking Medical Procedures

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Typical CO2 Laser System Uses

Uses for CO2 Lasers: For this Presentation: We’ll Discuss 2D Cutting Lasers

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Laser Measurement Equipment

Legacy Products: Simple Thermopile “Power Puck” Acrylic Block “Mode Burn” Short Time Periods Subjective Measurements Single Data Points

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Legacy Products: Simple Thermopile “Power Puck” • Fire Laser for Given Time • Wait for Response • Single Data Point

• Collection of Laser Behavior Over That Period of Time • No Trending Data

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Legacy Products: Acrylic Block “Mode Burn” • Fire Laser for Given Time • Safety Concerns?? • Single Data Point

• Collection of Laser Behavior Over That Period of Time • No Trending Data

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Power Measurement Thermopiles:

• Many Different Solutions: • Water-Cooled Sensors • Local Reading or Interfaces with

Meter or Local PC for Real-Time Power Measurement

• Measure Power Continuously for Several Minutes

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Electronic Beam Analyzers: • Beam Passed Through to Beam

Dump or Power Measurement Sensor

• Spinning Mirror or Needle Samples Small Percentage of Beam

• Interfaces with Local PC or Laser System for Rapid Viewing and Measurement of Raw Beam

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Combined Systems:

• Two Systems Working Simultaneously:

• Laser Beam Profiling System: • Signal sent to local PC for Analysis

• Laser Power Measurement System:

• Thermopile Sensor coupled with Local PC for Analysis

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Measurements Taken

Which Laser Measurements Are Important For CO2 Cutting Laser Systems? 1. Laser Power 2. Beam Size 3. Beam Shape 4. Beam Ellipticity 5. Beam Position

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Measurements Taken

Measurement 1: Beam Power

Graph of Laser Power vs. Time:

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Measurements Taken

Beam Analysis Software: Measurements 2-5: Beam Size Beam Shape Beam Ellipticity Beam Position

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Why These Measurements Are Important

Laser Parameter Measurements:

1. Laser Power • Difference between programmed power and

measured power should not be more than 10% • Should Stabilize and Hold within 30-45 Seconds After

Beam On Time

Healthy Laser Unhealthy Laser

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1. Laser Power • Healthy Laser: Power loss <10% between power

programmed and power measured

2000W Programmed 1960W Measured

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1. Laser Power • Less Than Healthy Laser: Contaminated optics

caused power loss >10% between power programmed and power measured

4000W Programmed 3460W Measured

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1. Laser Power • Unhealthy Laser: Damaged output coupler caused

power to never reach demand and drifting down

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1. Laser Power • Unhealthy Laser: Leak in resonator caused power

instability for several seconds until reaching demand power

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2. Beam Shape • Looking for Shape that is Balanced and

Consistent Over Time • Many Different “Shapes” / Modes

Most are Conical (“Gaussian”/TEM00) or Donut (TEM01*)

Gaussian Mode Donut Mode Combination

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Bad Beam Shape Examples: • Unbalanced Mode (5kW Laser / Optical Misalignment):

2D Profile • Energy Off-Center • Elliptical

Good Cuts

Bad Cuts

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Bad Beam Shape Example: • Inconsistent Mode (4kW Laser / 5 Second Measurement):

Time: 0.0 sec. Time: 0.5 sec. Time: 1.0 sec. Time: 1.5 sec.


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3. Beam Size • Relative Measurement:

Looking for a beam size that is consistent over several seconds

• Absolute Measurement: Looking for a beam size that is consistent with what the OEM specifications are Changes in beam size from what is expected will translate into a difference in what the laser is designed to do.

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Bad Beam Size Example: • Inconsistent Size (4kW Laser / 5 Second Measurement):



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4. Beam Ellipticity • 92-100% - “Good” • 88-92% - “Questionable” • 88% or Less – Action Should Be Taken

Usually elliptical beams are caused by some kind of optical misalignment. It should be a concern to the user since the cuts will be different between directions.

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5. Beam Position / Pointing Stability • Beam analysis software will also measure the beam

position over a long period time • Problems usually come from the laser design – not

much can be done. Sometimes from optics.

Bad Laser Good Laser

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CO2 Laser System Measurements

Conclusions: • Without real-time laser measurement tools,

the laser user cannot fully understand how their laser is behaving.

• If the measurements aren’t taken in this way, the laser system is susceptible to low efficiency and high maintenance costs.

• Electronic methods of laser power measurement and beam analysis gives the laser user a way to fully optimize their laser system and its processes.

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Thank You!

Laser Focus World Webinar - Ophir Optronics Focus World Webinar The Importance of Electronic CO 2...

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