Search
Menu
Lumencor Inc. - ZIVA Light Engine 3-24 LB

Stimulated Emission Enhances Fluorescence Detection

Facebook X LinkedIn Email
Stimulated emission (SE) can now be used to detect the signal-to-noise ratio (SNR) of fluorescence and convert it to a coherent signal.

A technique developed by a team from National Yang-Ming University’s Institute of Biophotonics Engineering induces the electronic transition of an excited fluorophore optical signal into SE before its energy dissipates through other radiative or nonradiative decay processes.

This makes the SE signals dependent on the population of the excited states and the intensity of the stimulation beam. The signals scale linearly with both excitation and stimulation beams, which give it an overall quadratic power dependence.


Scientists can now use stimulated emission to detect the signal-to-noise of fluorescence. Courtesy of National Yang-Ming University.

In this study, the researchers used destructive interference, generated by a Michelson interferometer, to reduce the high direct current (DC) background signal from the stimulation beam, thus increasing the SNR. This method reduces the direct current signal but not the SE signal. To improve the detection limit, the team reduced the stimulation beam power from 2 mW to 0.2 mW. 

Meadowlark Optics - Building system MR 7/23

In the past, the researchers established SE-based detection in long-working-distance settings by implementing the method of pump-probe with lock-in detection. This scheme can easily be used for other applications, they said, including the acquisition and reconstruction of fluorescence lifetime images by introducing an electronic delay between the pump and probe beams.

More recently, SE has been harnessed to acquire fluorescence lifetime data, improve the spatial resolution of micrographs, interrogate dark fluorophores, and detect fluorophores over a long working distance.

Now in development is the technique's potential for high-resolution 3-D biological imaging by optical coherence tomography, using fluorescence as a viable and unique contrast.

The work was funded by the National Science Council of Taiwan. It is published in Biomedical Optics & Medical Imaging.

For more information, visit www.ym.edu.tw.

Published: March 2014
Glossary
fluorescence
Fluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other electromagnetic radiation. Specifically, fluorescence involves the absorption of light at one wavelength and the subsequent re-emission of light at a longer wavelength. The emitted light occurs almost instantaneously and ceases when the excitation light source is removed. Key characteristics of fluorescence include: Excitation and emission wavelengths: Fluorescent materials...
fluorophore
A fluorophore is a molecule or a portion of a molecule that has the ability to emit light upon excitation by an external energy source, such as ultraviolet or visible light. The process by which a fluorophore absorbs and then re-emits light is known as fluorescence. Fluorophores are widely used in various scientific and technological applications, including fluorescence microscopy, flow cytometry, medical imaging, and molecular biology. Key features of fluorophores include: Excitation and...
optical coherence tomography
Optical coherence tomography (OCT) is a non-invasive imaging technique used in medical and scientific fields to capture high-resolution, cross-sectional images of biological tissues. It provides detailed, real-time, and three-dimensional visualization of tissue structures at the micrometer scale. OCT is particularly valuable in ophthalmology, cardiology, dermatology, and various other medical specialties. Here are the key features and components of optical coherence tomography: Principle of...
signal-to-noise ratio
The ratio of the power in a desired signal to the undesirable noise present in the absence of a signal.
stimulated emission
Radiation similar in origin to spontaneous emission but determined by the presence of other radiation having the same frequency. Because the phase and amplitude of the stimulated wave depend on the stimulating wave, this radiation is coherent with the stimulating wave. The rate of stimulated emission is proportional to the intensity of the stimulating radiation.
3-D biological imagingAsia-PacificfluorescencefluorophoreImagingLight SourcesMicroscopyNational Yang-Ming Universityoptical coherence tomographyOpticspHResearch & TechnologySensors & Detectorssignal-to-noise ratioSNRstimulated emissionTaiwanTech Pulsecellular metabolismSEInstitute of Biophotonics Engineeringcytoplasm matrix viscositymicrographs

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.