Fluorescence Detection System Using Optical Multiplexer Filters
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Solution Overview
Problem
Conventional fluorescence detection systems face challenges in achieving high sensitivity due to excitation light leakage, which increases background noise, especially when dealing with small samples.
Innovation Solution
The system incorporates a multi-wavelength selection mechanism using optical multiplexer/demultiplexers with specific filters to selectively transmit or reflect excitation light wavelengths, preventing unwanted light from reaching the detector, thereby enhancing sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional fluorescence analysis device is used with a light source, then excitation light can be provided to the sample, but excitation light leaks into the detector to increase background noise, decreasing sensitivity
Solution Approach 1:
The optical path is segmented into multiple channels with dedicated wavelength selection members. The excitation light path and fluorescence detection path are separated, with each path having its own filter to select specific wavelengths, preventing excitation light from contaminating the detection channel.
Solution Approach 2:
Wavelength selection members (filters) are introduced as intermediary components between the light source and detector. These filters act as mediators that selectively transmit desired wavelengths while blocking unwanted excitation light wavelengths, thereby reducing background noise without eliminating the excitation light source.
2Object-affected harmful factors
If a single wavelength selection member is used in the optical multiplexer/demultiplexer, then some wavelength filtering is achieved, but excitation light at certain wavelengths still reaches the detector
Solution Approach 1:
The single wavelength selection function is segmented into multiple specialized filters positioned at different locations in the optical path. Each filter handles a specific wavelength range, collectively providing comprehensive excitation light rejection while maintaining a manageable device structure.
Solution Approach 2:
Instead of using one perfect broadband filter, multiple narrower-band filters are used to provide excessive wavelength selection coverage. This ensures that all possible excitation light wavelengths are blocked, even though it increases the number of components.
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 effectively reduces background noise from excitation light, allowing for high-sensitivity fluorescence detection even with small sample amounts.
Implementation Method 1
a first wavelength selection member adapted to transmit only the light whose wavelength is longer than a predetermined first wavelength and reflect the light whose wavelength is shorter than a predetermined second wavelength
Implementation Method 2
a second wavelength selection member arranged between the light source and the first wavelength selection member on the waveguide and adapted to transmit only the light whose wavelength is shorter than a predetermined third wavelength
Implementation Method 3
an optical multiplexer/demultiplexer adapted to multiplex and demultiplex fluorescence generated from the sample irradiated with the excitation light through the probe
Data Source
AI summary
A fluorescence detection system capable of detecting fluorescence with a high sensitivity even if a sample generating fluorescence is small in amount includes a light source emitting excitation light, a probe arranged in opposition to a sample unit, an optical multiplexer/demultiplexer, a detector, a first optical fiber connecting the light source to the optical multiplexer/demultiplexer, a second optical fiber connecting the probe to the optical multiplexer/demultiplexer, and a third optical fiber connecting the detector to the optical multiplexer/demultiplexer. An excitation filter, serving as a short-pass filter, is arranged on the first optical fiber and a detection filter serving as a long-pass filter is arranged on the third optical fiber. The optical multiplexer/demultiplexer includes a multiplexing/demultiplexing filter serving as a long-pass filter.