Inline Welding Process Monitor

IPG’s new monitoring systems are the next paradigm in industrial weld quality assurance. The LDD-700 weld monitoring system uses Inline Coherent Imaging (ICI) to provide a new level of detail and accuracy for laser weld monitoring. ICI uses a low-power IR laser beam to gauge distances. This measurement beam is fired through the same optics as the welding laser, right to the bottom of the keyhole, and records its depth in real-time. The result is a direct, geometric measurement of weld penetration, acquired in-process. This data is comparable to a cut and etch of the entire length of the weld—for every weld—without destroying the part—and the results are available instantly.



Multi-factor Monitoring


  • Keyhole Depth
  • Workpiece Height
  • Seam Position
  • Finished Weld Profile
  • Transverse Weld Profile


Direct Weld Penetration

Active Process Control
Automatic PASS/FAIL
Seamless Integration with IPG Beam Delivery
 Measurement Principle Inline Coherent Imaging
 Imaging Wavelength, nm 800-900
 Power, mW <20 
Measurement Frequency, kHz 250
 Axial Resolution, μm <20
 Axial Field of View, mm 6, 9, 12
Transverse Resolution*, μm 25 typ.
Transverse Field of View, mm Up to 40 (application dependent)


* Depends on delivery optics. Typical value shown.

 Control Unit Dimensions, mm 536 × 413 × 184
 Head Interface Dimensions, mm 128 × 74 × 89
 Optics Module Dimensions, mm 330 × 111 × 136
Head Interface Compatibility Compatible with virtually all fixed-optic camera ports
Cooling Air-cooled
 Supply Voltage, V 100 to 250
 Power Consumption, W <500 typ.
 Real Time Control Outputs -10 to 10 V analogue, TCP/IP, Fieldbus
LDD-700 Inline Weld Monitor DatasheetLDD-700 Application NoteLaser Weld - Monitoring and Control Brochure




  • Automotive Powertrain
  • Automotive Fuelling
  • Automotive Seating
  • Pressure Vessels
  • Medical Devices
  • Batteries
  • E-vehicle Components
  • Turbines (Energy and Aerospace)
Powder-bed Additive
Wire-feed Additive

Drilling and Shaping

Academic R&D

On-board scanner mirrors allow the measurement beam to move independently of the welding beam, collecting additional data immediately ahead of and behind the melt pool on sub-ms time scales. A single LDD-700 can monitor up to five different streams of welding data simultaneously, (and extract multiple metrics from each), replacing several previous-generation instruments and giving you unparalleled certainty in the quality of your products.

3D imaging modes allow the LDD-700 to adapt to changes in the keyhole geometry for different processes—an essential capability for accurate depth measurements under real-world conditions. Powerful software allows full customization of the monitoring solution to meet the needs of the process.

Take the guesswork out of laser weld QA. Contact us at sales.ca@ipgphotonics.com for more information. 


Core Module
LDD-700 Core Module

Optics Module

LDD-700 Optics Module
Head Module
LDD-700 Head Module
For your convenience, we have sales offices in many locations. Here you can contact our Sales Force, request literature, ask us a question.