Light, as we know, sustains the web of life on Earth. Sunlight (absorbed by chlorophyll) is essential for the photosynthesis that occurs in plants, to produce the food we eat and release the oxygen we breathe. Furthermore, many organisms make use of this interaction in basic sensory mechanisms to guide their behavior, whether through a complex process such as vision or the microorganism's relatively simpler photosensitivity. From an engineering perspective, it is this interaction between light and matter that forms the basis of a wide range of technologies, including lasers, LEDs and atomic clocks.
Fig.1: Rainbow – Light of different colors has different indices of refraction
It is well known that matter is made up of atoms. These atoms are composed of a nucleus surrounded by layers of electronic energy. Light interacts with these electron layers. Light as energy can be absorbed by an electron layer and then several actions can take place. When light interacts with matter, it can do several things depending on its wavelength and the type of matter it encounters: it can be transmitted, reflected, refracted, diffracted, adsorbed, or scattered.
Light interacts as a particle or as a wave that behaves like a particle that undergoes absorption, scattering or pair production depending on the atomic number and frequency of the light. When the wavelength of light is comparable to the interatomic distance, it behaves like a wave and is diffracted. For very high intensity light, the interaction becomes nonlinear and is dominated by frequency mixing processes.
Multidisciplinary Applications
In fact, the study of light is a multidisciplinary science that involves many branches such as medicine, architecture and entertainment. Light has profound implications for the field of medicine, both as a cause of diseases such as UV damage to DNA, and as a therapeutic agent such as photodynamic therapy. Such processes are the basis of the science of photobiology, which could be defined as the study of the effects of visible and ultraviolet light from natural sunlight as well as artificial sources on living matter.
In addition to being striking examples of architecture, some buildings demonstrate the powerful effect through elements such as space, light, geometry and materials that can alter our mood. With abundant views and natural light, people can observe the activity and natural world outside and those outside get an idea of what is happening inside. They are separate but connected, and they help connect their communities.
Lasers have also proven their usefulness in the realm of art and entertainment, from “light shows” to compact discs (CDs) and digital video discs (DVDs), to special effects in films.
Applications in Medicine
Many forms of light (electromagnetic radiation) find some application in medicine. Advances in lightweight technology have revolutionized the medical industry. The medical imaging process involves creating visual representations of the inside of a body for later medical analysis.
Medical imaging, surgical procedures, and diagnostics rely on the use of light. These images are generally used in medical areas such as neuroscience, cardiology, psychiatry and psychology, among others. Visible light is the most common and important, as it is used to see and evaluate patients through the doctor's eyes. Nowadays, visible light is used for medical photography.
Fig. 2: X-ray – Optimizing electromagnetic radiant energy
The role of light in medical procedures has grown immensely. Lasers of different colors are used in all types of diagnostic and surgical procedures. Lasers come in a variety of wavelengths and can be used to break up kidney stones, cauterize bleeding, or vaporize tumors. The argon laser has been used to stop liver bleeding. Infrared light is used for imaging and also to warm premature babies. Radio waves are used in magnetic resonance imaging. Ultraviolet light can be used for sterilization. X-rays are used to see bones and kill tumors. Ultraviolet light is used in psoriasis, while ultraviolet lasers are used in corneal refractive procedures.
Higher energy electromagnetic energy (X-rays) is used in computed tomography machines and for plain film X-ray imaging. X-rays can treat certain forms of cancer. Gamma rays, as higher energy forms of electromagnetic radiation, can be used to treat cancer. Gamma rays are also detected in PET scans and used in gamma knife surgery for brain tumors.
Applications in Architecture
Lighting is considered a very important field in architecture, interior design and electrical engineering that is concerned with designing lighting systems like daylight, electric light or both to meet human needs. The design process takes into consideration the amount of light needed. Accompanied by the belief that light and shine could help create iconic architecture and a better human world, glass and metal were innovatively transformed to create crystal clear images. As a result, it was transferred from an internal spatial form to an external surface in architecture.
Figure 3: Nanotechnology – Nanocrystals that emit visible light
There are examples in contemporary architecture that have used light in a masterful way through the control of light and materials, as they allow each space to calmly show its personality to the user. In some buildings, the light becomes almost unreal when combined with the darkness of the materials, the stone, the reflections in the water and the steam that build a unique atmosphere.
Photometric studies are sometimes called “layouts” or “point by point”. They are used to simulate lighting designs for projects before they are built or renovated. These types of approaches help architects, lighting designers, and engineers determine whether a proposed lighting configuration will provide the intended amount of light. They also determine the contrast ratio between light. Such studies are referenced in lighting practices recommended by IESNA or CIBSE for the type of application.
Design aspects must take into account safety or practicality in maintaining uniform light levels, avoiding glare or emphasizing certain areas. A specialized lighting design application is used to create and combine the use of two-dimensional digital CAD drawings and lighting simulation software. Accompanied by the belief that light and shine could help create iconic architecture and a better human world, glass and metal were innovatively transformed to create crystal clear images. Some projects are notable not only for their innovative way of handling tangible materials, but also for their imagination regarding the medium of light. The theories of fragmentation and fluidity are now well-known design techniques in the field of architecture.
Entertainment applications
Professional lighting has been proven to provide much more than just the right level of brightness. It creates the mood and supports the lighting designers’ compositions and concepts. Creating various environments that express emotions is one of the main functions of lighting and makes it a central design element in film and TV productions. The right kind of light denotes tension, excitement, drama, joy and fascination. Thus, lighting plays an important role in creating unforgettable moments in TV and film productions.
Fig. 4: Laser projector – Revolutionizing home entertainment
Lasers have also proven their usefulness in the realm of art and entertainment. A laser beam is a wand of light that can be both beautiful and practical. The sight of a deep red sunset or a multicolored rainbow often inspires feelings of happiness, romance, and even awe. For many centuries, artists have tried to reproduce the beauty of light in paintings. Inventors gave artists mechanical tools like the camera that uses light to create art. This is really fun and beautiful as seen in the movie. Young Sherlock Holmes was the first film to use a laser to print images directly onto film. It was released in 1985 and ILM (Industrial Light and Magic) created the most special effects. In one of his scenes, a knight painted in a church window comes to life. Then Knight jumps out of the window and throws a priest out of the church. Likewise, many science fiction films not only utilize lasers in creating their special effects, but also regularly depict lasers or laser-like devices. In fact, real lasers have added a new and visually exciting dimension to the world of entertainment. It is expected that scientists and artists will continue to combine their talents to produce many new creative and dramatic forms of laser-based entertainment in the future.
Can light-matter interaction be improved?
Most light-matter interaction processes are prohibited by electronic selection rules that limit the number of transitions between energy levels. Because the atom is much smaller than the wavelength of the emitted light – about 1/1,000 to 1/10,000 the size – this substantially impairs interactions between the two. However, a new study from the Massachusetts Institute of Technology (MIT) could open up new areas of technology to make the momentum of light particles, called photons, more closely match that of electrons, which is typically many orders of magnitude. bigger.
Fig. 5: Solar technology – Aiming for greater efficiency
According to researchers, if we can “decrease” the wavelengths of light by orders of magnitude, reducing them almost to the atomic scale, this will allow a whole range of interactions related to the absorption or emission of light. In the two-dimensional material called graphene, light can interact with matter in the form of plasmons, a type of electromagnetic oscillation in the material that makes interactions at a much greater magnitude than they would be in ordinary materials. Utilizing these forbidden transitions could open up the ability to tailor the optical properties of materials in unprecedented ways.
This research systematically explores how 2-D materials improve light-matter interactions, establishing a theoretical basis for faster electronic transitions, improved detection and better emission, including the compact generation of broadband and quantum light. Closely confined, the light can then be absorbed by the semiconductor or emitted by it. This shrinkage could lead to new types of solar cells capable of absorbing a wider range of wavelengths of light, which would make the devices more efficient at converting sunlight into electricity. It could also lead to the production of devices such as lasers and LEDs that could be electronically adjusted to produce a wide range of colors.
In short
The enhanced interaction of light with matter is poised to revolutionize the fields of medicine, architecture, the entertainment industry, and more. In fact, the use of more advanced technology has endless possibilities for a variety of applications across multiple disciplines, such as spectroscopy and sensing devices, ultrathin solar cells, new types of materials to absorb solar energy, more efficient highly tunable lasers or diodes. light emitters (LEDs). ) and photon sources for possible quantum computing devices.