Optical Parameters
Optical Parameters - Related Videos
08:31
Three-dimensional Optical-resolution Photoacoustic Microscopy
0 Views •
Cited by 27 •
2011
Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technology capable of imaging optical absorption contrasts in vivo with cellular resolution and sensitivity. Here, we provide a visualized instruction on the experimental protocols of OR-PAM, including system configuration, system alignment, typical in vivo experimental procedures, and functional imaging schemes.
09:39
Optical Biosensing
0 Views •
2023
Optical biosensors utilize light to detect the binding of a target molecule. These sensors can utilize a label molecule, which produces a measurable signal such as fluorescence, or these sensors can be label-free and use the changes in optical properties, such as refractive index, to sense for the binding of the target molecule. This video introduces both label and label-free optical biosensors, demonstrates their use in the laboratory, and shows some applications of the technology.
01:10
Wave Parameters
0 Views •
2023
The simplest mechanical waves are associated with simple harmonic motion and repeat themselves for several cycles. These simple harmonic waves can be modeled using a combination of sine and cosine functions. Consider a simplified surface water wave that moves across the water's surface. Unlike complex ocean waves, in surface water waves, water moves vertically, oscillating up and down, whereas the disturbance of the wave moves horizontally through the medium. If a seagull is floating on the...
07:46
Optical Materialography Part 2: Image Analysis
0 Views •
2023
Source: Faisal Alamgir, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA The imaging of microscopic structures of solid materials, and the analysis of the structural components imaged, is known as materialography. Often, we would like to quantify the internal three-dimensional microstructure of a material using only the structural features evidenced by an exposed two-dimensional surface. While X-ray based tomographical methods can reveal buried...
14:09
Quantitative Optical Microscopy: Measurement of Cellular Biophysical Features with a Standard Optical Microscope
0 Views •
Cited by 11 •
2014
We describe the use of a standard optical microscope to perform quantitative measurements of cellular mass, volume, and density through a combination of bright field and differential interference contrast imagery.
FAQs
Absorption removes photons as tissue components interact with specific wavelengths, while scattering changes photon direction and lengthens their paths. Because both effects vary with wavelength, the detected signal can show changes in attenuation, reflection, and propagation. Separating these contributions helps interpret optical measurements as indicators of tissue composition or physiological state.
Refractive index influences how light changes direction when it encounters tissue interfaces or components. Anisotropy describes the directional character of scattering, indicating whether photons are preferentially redirected in particular directions. Considering both properties improves interpretation of light transport, especially when measurements depend on reflection, propagation pathways, or the spatial distribution of detected optical signals.
Signal attenuation reflects the combined influence of absorption and scattering rather than a single tissue property. Refractive index and anisotropy further affect photon trajectories and therefore the amount and direction of light reaching a detector. Evaluating the parameters together provides a more complete basis for interpreting wavelength-dependent optical measurements in biological tissue.
Assessment focuses on measuring how tissue modifies light across relevant wavelengths, including changes associated with absorption, scattering, reflection, and attenuation. The resulting parameter information can then be used to interpret optical signals rather than treating detector intensity as a direct tissue measurement. This approach supports analysis in imaging, spectroscopy, and other medical optical methods.
In diffuse optical imaging, tissue scattering and absorption determine how light spreads before detection, influencing the recorded spatial and wavelength-dependent signal. Spectroscopy uses related optical changes to distinguish tissue composition. Parameter measurements therefore help researchers connect observed signals with tissue properties and physiological information, improving interpretation of measurements obtained through these medical techniques.
Pulse oximetry depends on interpreting wavelength-specific changes in tissue optical signals, while photodynamic therapy and laser-based procedures require control of how light interacts with tissue. Absorption, scattering, and related properties help describe signal behavior and light delivery. Their measurement supports physiological monitoring, tissue discrimination, and selection or control of light dose in clinical research and procedures.