Beam-Splitter Laser Calibration for High-Power DMLM Beams

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Solution Overview

Problem

Conventional methods and equipment for calibrating high power density lasers used in direct metal laser melting are impractical due to rapid degradation of calibration equipment, including optical components and sensors, necessitating an accurate and durable calibration system.

Innovation Solution

A laser calibration system that utilizes a beam splitter to split the laser beam into reflected and transmitted portions, with the reflected portion carrying reduced power to prevent degradation of optical components and sensors, and a controller to analyze beam parameters and power levels, ensuring precise calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional calibration equipment is used to calibrate high power density lasers, then calibration can be performed, but the calibration equipment rapidly degrades including optical components and sensors

Engineering Contradiction:

Improvelaser calibration accuracyVSAvoidcalibration equipment durability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

A beam splitter is introduced as an intermediary component between the high power density laser and the calibration sensor. The beam splitter divides the laser beam into a calibration beam (lower power) directed to the sensor and a main beam (higher power) continuing to the focal point. This mediator protects the sensor from direct exposure to damaging high power while enabling calibration functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The laser beam is segmented into two separate paths using the beam splitter: a calibration path with reduced power density directed to the sensor for measurement, and a main processing path with full power density directed to the focal point for actual work. This segmentation allows the sensor to operate within safe power limits while the system maintains full laser capability.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the full power laser beam is directed to calibration sensors, then accurate calibration data can be obtained, but the sensors and optical components are damaged

Engineering Contradiction:

Improvebeam parameter measurement accuracyVSAvoidlaser power density damage to components

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The beam splitter serves as a protective intermediary that reduces the power density of the laser beam before it reaches the sensor. By reflecting or transmitting only a portion of the beam, it enables measurement without exposing the sensor to harmful high power density levels that would cause damage.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the power density parameter of the laser beam by using the beam splitter to create a lower power density calibration beam. This parameter modification allows the sensor to receive sufficient light for accurate measurement while staying below the damage threshold.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If a beam splitter is used to reduce power to sensors, then component durability is improved, but system complexity increases

Engineering Contradiction:

Improveoptical component durabilityVSAvoidcalibration system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The beam splitter performs multiple functions simultaneously: it protects the sensor from high power damage, enables calibration measurements, and allows the main laser beam to continue to the work area. This multi-functionality justifies the added component by providing several benefits from a single element.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively prevents damage to optical components and sensors while providing accurate calibration of high power density lasers, maintaining system integrity and performance.

Implementation Method 1

a beam splitter is disposed in the optical path between the laser system and the steerable mirror in order to reflect part of the laser light towards a sensor

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentEP3651920B1Sensor system for directly calibrating high power density lasers used in direct metal laser melting

Publication Date: 2026.04.22 3D SYSTEMS INC

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AI summary

A three dimensional printing system includes a laser system, a beam splitter, a pinhole, a sensor, and a controller. The laser system emits a light beam of varying diameter carrying at least 100 watts of optical power along an optical path. The laser has an imaging plane along the optical path which can be coincident or close to a focal plane at which the beam has a minimum diameter. The beam splitter is positioned along the optical path to receive the beam and to transmit most of the optical power and to reflect remaining optical power. The pinhole is positioned along the optical path at the imaging plane to receive the reflected beam having a minimal diameter. The controller is configured to analyze a signal from the sensor to determine intensity and distribution parameters for the light beam.