Optical Transmission Sample Holder Multi-Wavelength Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical transmission analysis methods for thin samples sandwiched between two plates face challenges in separating light absorption by the sample holder from that by the sample, due to assumptions about air bubbles and light scattering, leading to inaccurate measurements.
Innovation Solution
The use of a dual-band or triple-band bandpass filter and an RGB Bayer filter in conjunction with a single white light source and imaging lens, allowing for the measurement of light absorption at multiple wavelengths with a single color camera, and image processing to separate sample and sample holder signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a sample holder with two plates is used to sandwich a thin layer sample, then the sample can be held for measurement, but the light absorption by the sample holder cannot be separated from that by the sample
Solution Approach 1:
The sample holder is divided into two distinct regions: a sample region where the sample is placed and a reference region where no sample is present. This segmentation allows separate measurement of sample holder absorption (in reference region) and total absorption (in sample region), enabling mathematical separation of sample and holder contributions to the measurement.
Solution Approach 2:
An air bubble is introduced as an intermediary reference element within the sample holder. The air bubble creates a reference region with known optical properties (air has minimal absorption), serving as a mediator to measure and subtract the sample holder's absorption contribution from the total measurement.
2Device complexity
If air bubbles are used as reference signals to separate sample holder absorption from sample absorption, then single photodetector measurement is enabled, but measurement accuracy deteriorates due to random bubble generation and location
Solution Approach 1:
Instead of relying on random air bubble formation during measurement, the reference region is pre-defined during sample holder design. The reference region is specifically engineered to exclude sample presence while maintaining identical sample holder geometry, ensuring consistent and accurate reference measurements before actual sample analysis begins.
Solution Approach 2:
The reference region is designed as a precise copy of the sample region geometry, including identical plate configurations and path lengths, but without the sample present. This copying approach ensures that all sample holder contributions are identical between regions, allowing accurate subtraction to isolate sample absorption.
3Measurement precision
If multi-wavelength measurement is performed to improve analysis accuracy, then sample characterization is enhanced, but device complexity increases requiring multiple light sources and detectors
Solution Approach 1:
A single photodetector is designed to perform multiple functions by detecting light at multiple wavelengths sequentially. The system uses a single light source that emits broad spectrum or sequentially emits different wavelengths, with the same photodetector measuring absorption at each wavelength, eliminating the need for multiple dedicated detector systems.
Solution Approach 2:
The multi-wavelength measurement is achieved through periodic switching between different wavelengths using wavelength-selective filters or tunable filters. The system sequentially presents different wavelengths to the sample and measures absorption at each, allowing comprehensive spectral analysis with a single detector through time-multiplexed operation.
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 enhances the accuracy of optical transmission measurements by effectively distinguishing between sample and sample holder absorption, reducing errors and improving measurement precision.
Implementation Method 1
a dual-band or triple-band bandpass filter to, e.g., selectively, filter the white light into component colors prior to interrogating the sample
Implementation Method 2
a RGB Bayer filter for filtering the light emitted from the interrogated sample
Implementation Method 3
an imaging lens (for example, a single lens or a plurality of lenses. The function of the imaging lens is to allow enhanced imaging on the sensor)
Implementation Method 4
measure the intensity of the incident light and the transmitted light that directly goes in and out of a sample
Data Source
AI summary
The disclosure provides an apparatus, a device, and methods for improving optical analysis of a thin layer of a sample between two plates, particularly for multiple wavelengths.