Optical Attenuator Using Half Mirrors for Stable Beam Output

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Solution Overview

Problem

Existing optical attenuators cannot attenuate laser beam output without altering the beam position or diameter, posing challenges in precise measurement and processing.

Innovation Solution

A high-output optical attenuator using a combination of total reflection mirrors and half mirrors to divert and attenuate the laser beam without changing its position or diameter, allowing for accurate detection by photodetectors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a filter is used to attenuate the laser beam, then the beam output is reduced, but the beam position and beam diameter change

Engineering Contradiction:

Improvebeam outputVSAvoidbeam position and beam diameter stability

Core Design Contradiction:

PowerVSManufacturing precision

Solution Approach 1:

The optical system is divided into multiple independent optical paths using beam splitters. The incident light is divided into a reference light path and a measurement light path, allowing independent control and measurement without mutual interference. This segmentation enables precise control of beam output attenuation while maintaining beam position and diameter stability in the measurement path.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A beam splitter is introduced as an intermediary optical element that divides the incident light into separate paths. This mediator allows the reference light to be attenuated or redirected while the measurement light maintains its original characteristics, thus achieving output control without affecting beam position and diameter in the measurement path.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If the beam output is attenuated using conventional methods, then the power is reduced, but the measurement precision deteriorates due to position and diameter changes

Engineering Contradiction:

Improvebeam outputVSAvoidbeam position and beam diameter measurement accuracy

Core Design Contradiction:

PowerVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The beam splitter creates a reference light path that is a copy of the original beam path. This reference path allows for indirect measurement and control of beam parameters without directly interfering with the measurement beam, thereby maintaining measurement precision while enabling output attenuation control.

Inventive Principle:

Principle #26Copying

3Power

If a filter is placed in the optical path to reduce beam output, then the power is attenuated, but the device complexity increases

Engineering Contradiction:

Improvebeam outputVSAvoidoptical system structure

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The beam splitter serves multiple functions simultaneously: it divides the light into reference and measurement paths, enables output attenuation control, maintains beam position and diameter stability, and facilitates precise measurement. This multi-functionality reduces the need for additional separate components, thereby controlling device complexity while achieving the desired attenuation and measurement capabilities.

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

Enables effective attenuation of high-output laser beams without shifting the beam position or altering the beam diameter, facilitating precise measurement and processing in applications like 3D shaping and laser processing.

Implementation Method 1

a first reflector (101) that totally reflects the incident light (120)

Methodology Applied

Scientific EffectTotal reflection: Total Internal Reflection

Implementation Method 2

a third reflector (103) and a fourth reflector (104) that are half mirrors and partially reflect the incident light (120)

Methodology Applied

Scientific EffectPartial reflection: Reflection

Data Source

PatentEP3088125B1High-output-light attenuator, measuring device, and three-dimensional modeling device

Publication Date: 2019.11.20 TECH RES ASSOC FOR FUTURE ADDITIVE MFG

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AI summary

This invention is directed to attenuating a beam output without changing the beam position and the beam diameter. A high-output optical attenuator includes a first reflector that totally reflects incident light and causes first reflected light serving as reflected light of the incident light to enter a second reflecting portion, a second reflector that reflects the first reflected light and causes second reflected light serving as reflected light of the first reflected light to enter a third reflecting portion, a third reflector that reflects the second reflected light and causes third reflected light serving as reflected light of the second reflected light to enter a fourth reflecting portion, and a fourth reflector that reflects the third reflected light as fourth reflected light having the same optical axis as the optical axis of the incident light. At least two of the second reflector, the third reflector, and the fourth reflector are half mirrors.