Optical Microscopy Using Absorption Saturation for High-S/N Imaging

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Solution Overview

Problem

Existing optical microscopes for tissue observation and pathological diagnosis often have complex configurations due to the use of two photon absorption or transient absorption, requiring expensive and difficult-to-handle pulse lasers, and struggle to achieve high S/N ratios.

Innovation Solution

An optical microscope with a simplified configuration using a CW laser light source, a modulator, and a light detector to generate and detect nonlinear components of signal light based on absorption saturation in a light-absorbing material, such as Eosin Y, allowing for high-resolution imaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If two photon absorption or transient absorption is used to achieve high-resolution imaging, then imaging resolution is improved, but apparatus complexity increases due to requirement of pulse laser

Engineering Contradiction:

Improveimaging resolutionVSAvoidapparatus complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the fundamental parameter of light interaction by using absorption saturation instead of two-photon or transient absorption. This allows the use of continuous wave lasers rather than pulse lasers, significantly simplifying the apparatus while maintaining high-resolution imaging capability through the detection of nonlinear absorption components

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive and complex pulse lasers with cheaper and simpler continuous wave lasers. Although continuous wave lasers are less powerful peak-wise, their continuous operation and simplicity make them more suitable for practical pathological diagnosis applications, reducing both cost and operational difficulty

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If pulse laser is used to induce nonlinear optical effect, then nonlinear optical effect is achieved, but cost and handling difficulty increase

Engineering Contradiction:

Improvenonlinear optical effectVSAvoidhandling difficulty

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the laser type parameter from pulse to continuous wave, fundamentally altering how nonlinear effects are achieved. Instead of relying on high peak power of pulse lasers, the system uses absorption saturation induced by continuous illumination, making the system easier to handle and more suitable for routine pathological diagnosis

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If fluorescence detection is used to detect signal light, then signal detection is achieved, but S/N ratio decreases

Engineering Contradiction:

Improvesignal detection capabilityVSAvoidS/N ratio

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent converts the typically problematic background fluorescence signal into a useful feature. By using absorption saturation, the system detects changes in absorbed light intensity rather than emitted fluorescence, effectively converting what would be interfering background signals into the desired measurement, thereby improving the S/N ratio

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent substitutes fluorescence emission detection with absorption saturation detection. Instead of detecting light that is emitted after excitation (fluorescence), the system detects changes in light that is absorbed, providing a more direct and higher signal-to-noise ratio measurement of the light-absorbing material's properties

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 high-resolution diagnostic imaging with a simplified apparatus, improving diagnostic accuracy and spatial resolution beyond the diffraction limit without the need for expensive pulse lasers or complex optical harmonics generation.

Implementation Method 1

a nonlinear region in which the laser light intensity and a signal light intensity have a nonlinear relation due to occurrence of saturation of absorption in the light absorbing material

Methodology Applied

Scientific EffectAbsorption saturation: Absorption (EM radiation)

Data Source

PatentUS12590886B2Optical microscope and imaging method

Publication Date: 2026.03.31 KYOTO PREFECTURAL PUBLIC UNVERSITY CORP

AI summary

A diagnostic optical microscope according to the present embodiment includes at least one laser light source (11) configured to generate laser light for illuminating a sample (40) containing a light absorbing material, a lens configured to focus the laser light to be focused on the sample (40), scanning means for changing a focusing position of the laser light on the sample (40), and a light detector (31) configured to detect laser light transmitted through the sample (40) as signal light. A laser light intensity is changed to obtain a nonlinear region in which the laser light intensity and a signal light intensity have a nonlinear relation due to occurrence of saturation of absorption in the light absorbing material when the laser light intensity is maximized. An image is generated based on a nonlinear component of the signal light based on the saturation of absorption in the light absorbing material.