Photonic crystals are those that manipulate how photons are absorbed or reflected off of them. They occur in nature and are made of dielectric nanostructures that allow certain wavelengths to pass through them while blocking other wavelengths. The visible light portion of the electromagnetic spectrum’s wavelengths is responsible for colors, therefore photonic crystals can spontaneously emit exotic colors. How Photonic Crystals Work Photonic crystals are made of nanoscale structures that either allow or block individual wavelengths of light, depending on the frequency of their dielectric constants. Each wavelength of light Read More

Electroluminescence is the phenomenon where a material emits light when electricity is passed through it. It is one of the greatest discoveries of the twentieth century and other forms of luminescence, including incandescence, chemiluminescence, cathodoluminescence, triboluminescence, and photoluminescence rival it. Electroluminescence generally involves a material producing light without producing heat. It is different from black body light emission, which only mechanical actions produce. How Electroluminescence Works Electroluminescence is produced when an electric current is passed through a semiconductor with tiny holes. As excited electrons pass over these holes, they are Read More

The speed of light in MPH is 670,616,629 mph, 299,792,458 meters per second, or 186, 282 miles per second. Light takes approximately one second to travel the 238,854 miles to the moon. The speed of light is considered a physical constant that is used in many areas of physics. This is because light always travels at this speed in space or in a vacuum regardless of the measurement source or observer. The most popular use of the speed of light is in Albert Einstein’s theory of relativity, E=mc^2, where c Read More

A stereomicroscope is generally known as a comparison microscope and it is used in scientific fields primarily for comparing two side by side specimens. A stereo microscope is made up of two regular microscopes connected together with an optical bridge. For instance in forensics, it may be necessary to compare to samples to each other, using a traditional microscope the viewer will need to memorize the contents and switch slides, however with the stereo microscope, the viewer can see both slides side by side at the same time. The stereo Read More

A laser printer unlike an inkjet printer uses a laser light beam for printing operations. It is also distinct from other printers because of its exceptional printing speed as well as highly accurate rendering. It utilizes a xerographic (a process of creating an image by the action of light on a specifically coated charged plate) printing. Some laser printers in the market can print a hundred colored pages and two hundred non-colored pages every minute. Resolution is a key characteristic of laser printer, measured in dots per inch (dpi). The Read More

An atomic force microscope, or AFM, is an instrument for mapping and measuring surface features of extremely small objects – from a carbon atom that is 0.25 nanometers (nm) or 2.5 Angstroms in diameter to a cross section of human hair (approximately 80 microns in diameter). Basic Principles of an Atomic Force Microscope The atomic force microscope is basically a miniaturized cantilever (a tiny beam is anchored at one end while another projects out into space like a diving board) with a tiny, pointed probe (with an extremely fine ceramic Read More

Parabolic mirrors are specially shaped in order to capture and focus energy onto a single point. They also distribute energy from a single point outwards. The mirrors are a specific paraboloid type that is rotated around its axis, and is also known as a circular paraboloid. Parabolic mirrors are also referred to as parabolic reflectors or parabolic dishes. When were Parabolic Mirrors First Used? Sir Isaac Newton was one of the first scientists to use parabolic mirrors in his reflecting telescope in the 17th century. By using the mirror, the Read More

Laser is the abbreviation of the term "light amplification by stimulated emission of radiation." It is an apparatus that emits a special form of light. The emission of light by a laser is known as stimulated emission. The essential parts of a laser are a gain medium and an optical cavity. There should also be an external source of energy to be supplied to the gain medium. Gain medium is a material that has got the characteristics to amplify light. The gain medium in a laser can be a material Read More

Holograms are three-dimensional images produced through photographic projection. Unlike 3-D graphics or Virtual Reality or Augmented reality displays where the image is projected in a two-dimensional surface and where the illusion of depth is applied, holograms are truly three-dimensional images that do not need special viewing equipments. The first hologram was created in 1947 by Dennis Gabor while doing research on improving the resolution of electron microscopes. The lasers needed for displaying and creating these holograms, however, did not exist until 1960. Categories of Holograms Holograms can be categorized into Read More

For the past two decades, lasers have been used to measure distance without having to physically touch the area or things being measured. Laser measurement is capable of very precise and quick distance measurements. Lasers have been used in military targeting, criminal investigations, and sports. As research has progressed, the size of laser measuring devices has decreased, while computer power capable of interpreting and using measurement data has increased. What Techniques Do Lasers Use to Measure Distance? A laser uses several techniques to measure distance. They include: Time of Flight Read More