Optical Phase Measurement Intensity Compensation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional phase-shift digital holography faces challenges in achieving high-definition phase measurements due to non-uniformity in intensity distributions between object and reference beams, leading to measurement errors, especially in systems with spatial division and multiple imaging devices.

Innovation Solution

An optical phase measuring method and device that detect intensity distributions of both object and reference beams in multiple sections, generating holograms with phase-shifted reference beams to compute phase information accurately, compensating for intensity differences and allowing continuous phase measurement without reducing frame rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If phase-shift digital holography is used to achieve high-definition phase measurement, then measurement precision is improved, but intensity non-uniformity between object and reference beams causes measurement errors

Engineering Contradiction:

Improvephase measurement accuracyVSAvoidmeasurement error due to intensity non-uniformity

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by detecting and storing the intensity distribution of the reference beam before it interferes with the object beam. This pre-detection allows the system to compensate for intensity non-uniformities during phase calculation, eliminating measurement errors caused by intensity variations between object and reference beams while maintaining high-definition phase measurement capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using the detected reference beam intensity distribution to correct the phase measurement calculation. The stored intensity information feeds back into the phase computation process, allowing real-time compensation for intensity non-uniformities and ensuring accurate phase measurement despite variations in beam intensity

Inventive Principle:

Principle #23Feedback

2Measurement precision

If multiple imaging devices are used for spatial division to improve measurement capability, then measurement precision is improved, but intensity distribution differences between devices increase measurement errors

Engineering Contradiction:

Improvephase measurement capabilityVSAvoidmeasurement error due to device intensity differences

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent detects the intensity distribution of the reference beam at each imaging device position before interference measurement. This preliminary detection at each device location enables subsequent compensation for device-specific intensity variations, allowing multiple imaging devices to work together accurately without being affected by their individual intensity distribution differences

Inventive Principle:

Principle #10Preliminary action

3Productivity

If frame rate is maintained for continuous measurement, then productivity is improved, but measurement accuracy may be compromised without intensity compensation

Engineering Contradiction:

Improvecontinuous measurement speedVSAvoidphase measurement accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary detection of the reference beam intensity distribution before the actual interference measurement. This pre-detection step enables rapid intensity compensation during phase calculation, allowing continuous high-speed measurement without sacrificing accuracy, as the compensation can be applied computationally without requiring additional physical measurement time

Inventive Principle:

Principle #10Preliminary action

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

This approach enables high-accuracy phase measurement by compensating for intensity non-uniformities and reducing measurement errors, enhancing the precision of phase information retrieval in digital holography applications.

Implementation Method 1

a hologram (interference fringes) made from an object beam from an inspection object and a reference beam which can interfere with the object beam

Methodology Applied

Scientific EffectInterference: Interference

Data Source

PatentUS9459155B2Method for measuring optical phase, device for measuring optical phase, and optical communication device

Publication Date: 2016.10.04 HOKKAIDO UNIVERSITY

AI summary

The present invention relates to an optical phase measuring method and an optical phase measuring device which can measure phase information contained in an object beam with high accuracy. Intensity distributions of a test object beam, a first reference beam and a first hologram made from the object beam and the first reference beam are detected by the first light intensity detection section. Intensity distributions of the test object beam, a second reference beam and a second hologram made from the object beam and the second reference beam are detected in the second light intensity detection section. Phase information contained in the object beam is computed on the basis of the intensity distributions detected in the first light intensity detection section and the intensity distributions detected in the second light intensity detection section.