RESEARCH FIELDS
https://www.britannica.com/science/polarization-physics#/media/1/467121/91342
Polarization is a property of certain electromagnetic radiations in which the direction and magnitude of the vibrating electric field are related in a specified way.
Light waves are transverse: the vibrating electric vector associated with each wave is perpendicular to the direction of propagation. A beam of unpolarized light consists of waves moving in the same direction with their electric vectors pointed in random orientations about the axis of propagation. Plane polarized light consists of waves in which the direction of vibration is the same for all waves. In circular polarization, the electric vector rotates about the direction of propagation as the wave progresses. Light may be polarized by reflection or by passing it through filters, such as certain crystals, that transmit vibration in one plane but not in others.
Britannica, T. Editors of Encyclopaedia (2020, July 17). polarization. Encyclopedia Britannica. https://www.britannica.com/science/polarization-physics
Encyclopædia Britannica. (n.d.). Diffraction grating. [undefined]. Britannica Academic. Retrieved July 6, 2022, from https://academic.eb.com/levels/collegiate/assembly/view/37362
Diffraction, the spreading of waves around obstacles. Diffraction takes place with sound; with electromagnetic radiation, such as light, X-rays, and gamma rays; and with very small moving particles such as atoms, neutrons, and electrons, which show wavelike properties. One consequence of diffraction is that sharp shadows are not produced. The phenomenon is the result of interference (i.e., when waves are superimposed, they may reinforce or cancel each other out) and is most pronounced when the wavelength of the radiation is comparable to the linear dimensions of the obstacle. When sound of various wavelengths or frequencies is emitted from a loudspeaker, the loudspeaker itself acts as an obstacle and casts a shadow to its rear so that only the longer bass notes are diffracted there. When a beam of light falls on the edge of an object, it will not continue in a straight line but will be slightly bent by the contact, causing a blur at the edge of the shadow of the object; the amount of bending will be proportional to the wavelength. When a stream of fast particles impinges on the atoms of a crystal, their paths are bent into a regular pattern, which can be recorded by directing the diffracted beam onto a photographic film.
Britannica, T. Editors of Encyclopaedia (2020, July 17). polarization. Encyclopedia Britannica. https://www.britannica.com/science/polarization-physics
Cense, B., Maddipatla, R., Lozano, F. J. C., & Joo, C. (2022). Two concepts for ultra-high-resolution polarization-sensitive optical coherence tomography with a single camera. JOSA A, 39(7), 1295-1308.
Optical coherence tomography (OCT) is a non-invasive imaging technique that now allows for simultaneous in vivo imaging of the morphology as well as the vasculature in the eye. In this review, we provide an update on the existing clinical applications of optical coherence tomography angiography technology from the anterior to the posterior segment of the eye. We also discuss the limitations of optical coherence tomography angiography technology, as well as the caveats to the interpretation of images. As current optical coherence tomography angiography systems are optimized for the retina, most studies have focused on interpreting images from conditions such as age-related macular degeneration and retinal vascular diseases. However, the interpretation of these optical coherence tomography angiography images should be taken into consideration with other multi-modal imaging to overcome the limitations of each technique. In addition, there are a growing variety of clinical applications for optical coherence tomography angiography imaging in optic nerve head evaluation for glaucoma and optic neuropathies. Further developments in anterior optical coherence tomography angiography have now allowed for evaluation of anterior segment pathology such as glaucoma, ocular surface diseases, corneal vascularisation, and abnormal iris vasculature. Future developments in software could allow for improved segmentation and image resolution with automated measurements and analysis.
Ang, M., Tan, A., Cheung, C., Keane, P. A., Dolz-Marco, R., Sng, C., & Schmetterer, L. (2018). Optical coherence tomography angiography: a review of current and future clinical applications. Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie, 256(2), 237–245. https://doi.org/10.1007/s00417-017-3896-2
https://www.synopsys.com/glossary/what-is-photonics.html
Photonics Dictionary defines photonics as “the technology for generating and harnessing light…whose quantum unit is the photon…” Its definition includes the means for producing, controlling, sensing/detecting light by optical components and instruments. It does include electro-optical instrumentation. Photonics is the broadest of the three terms. Electro-optics is defined as the “use of applied electrical fields to generate and control optical radiation. However, it would appear from this definition, and from others, that it would apply to material changes due to electric fields such as occur with liquid crystal displays, such as Kerr & Pockels effects. A warning is provided that “electro-optic (E-O) is often used erroneously as a synonym for optoelectronic.”
Finally, optoelectronics is said to pertain “to a device that responds to optical power, emits or modifies optical radiation or utilizes optical radiation for its internal operation” or “any device that functions as an electrical-to-optical or optical-to electrical transducer.”
Mohamed, F., & Siang, C. V. (2019). A Survey on 3D Ultrasound Reconstruction Techniques. In (Ed.), Artificial Intelligence – Applications in Medicine and Biology. IntechOpen. https://doi.org/10.5772/intechopen.81628
3D reconstruction is a method by which an object is re-created within a virtual, three-dimensional (3D) space using a computer. This can be done in a number of different ways, but usually involves the use of input data such as two-dimensional (2D) photographs or the scanning of the actual object. Once this 3D reconstruction is created, then it can be manipulated or utilized in a number of different ways, including for medical uses, law enforcement reconstructions, and even the creation of 3D graphics for film or television.
The creation of a 3D reconstruction usually involves digital image professionals, rather than 3D computer modelers, as the images are not usually created as much as they are assembled. There are two basic approaches to this type of reconstruction that can be used, based on how those involved gather the input data for the reconstruction. Active reconstruction involves some form of interference between the object being reconstructed and a sensor, such as scanning an object or taking photographs of it. Passive 3D reconstruction, on the other hand, uses sensors that receive data without interfering with the object at all, such as devices used to receive light from distant stars.