This optical amplification is started from some emission but it is not exposed yet until Albert Einstein proposed in 1916. After that, the things became more seriously after 1954 when Townes and Arthur Schawlow also with Gordon Gould proposed laser action, then not long after 4 years, in 1960, first laser was build by Theodore Maiman. Besides that, Gordon also derived the word laser from “light amplification by the stimulated emission of radiation”. The laser developer look amplification is very important as a step to build a laser, so these people make one advance to develop amplifiers from semiconductor laser to be used as light sources. This is because of semiconductor have high gain. Laser made up with high gain and low noise is categorized as the best laser.
Diagram 1 : The general form of an Optical Amplifier
The main type of Optical amplifier consists of three types which is Semiconductor Optical Amplifier (SOA), Raman Optical Amplifier and Rear-earth doped Fiber Amplifier (EDFA). Semiconductor Optical Amplifier (SOA) is a type of optical amplifier that is pumped by electric currents. So, this Optical Amplifier handles only less power and produce nosier than Rear-earth doped Fiber Amplifier (EDFA). It is also less expensive and suitable to be used in local. This type also use semiconductor to provide the gain medium. Semiconductor optical amplifier also relatively provide low gain and high noise figure.
Diagram 2 : Semiconductor Optical Amplifier
Raman optical amplifier is demonstrated since in the early of 1970 by Stolen and Ippen. But, by the early 2000 this type of Optical Amplifier is widely used and almost 300 to 800 km and even reaches above 800km length in fiber-optic transmission system. Due to advances in...
... middle of paper ...
...Divison Multiplexing , is a device that will be used optical fibre system because it can have one or more input and output fibers. In Addition, Optical isolater also used to allow light to flow in one direction and to avoid any unwanted feedback. The pump also used in Optical Amplifier. Most common pump used is 980 nm and 1480 nm. For 980 nm produced high gain and low noise and also provided low ASE ( Amplified Spontaneous Emission ) which is the background noise when the spontaneous emission also get amplified as the light travel to amplifying medium.
The basic principle used in this optical amplifier is the spontaneous emission and the stimulated emission. The light will be absorbed as they propagates. Light will be amplified as they travel in the medium where in the population of light is much greater in higher energy states compared to lower energy states.
Infra-red spectroscopy was first used in 1950's by Wilbur Kaye. He designed a machine that tested the near-infrared spectrum and was able to provide the theory to describe the results. There have been many advances in the field of IR Spec, the most applicable was the application of Fourier Transformations. ”The Fourier Transform is a tool that breaks a waveform (a function or signal) into an alternate representation, characterized by sine an...
Controlling chemiluminescent light was how Omniglow Incorporated became the first company to produce light sticks. In 1986, when the first light stick was invented, scientists thought they could make a lot of money selling light sticks. However, since they had to make light sticks by hand, it was harder for them to produce very many of them. Until machines were invented to make light sticks, it cost too much money to make them by hand.
Optical monochrome filters are used to filter out all the wavelengths except desired one. Since we are interested in Green, Red and Near Infrared wavelengths the following filters are used.
Oral and Maxillofacial surgery was the forerunner in using laser. There were attempts to replace surgical scalpel with electrocautery and later with laser. Some of the added advantages of Laser are
The true benefits of fiber optics become apparent, since it is not affected by electro-magnetic interference (EMI).
My interest into becoming an optometrist had begun when I was in high school; it happened in an unconventional way. It was not through watching videos, or someone explaining to me what optometry was, but rather, seeing the power of it firsthand. There was a point in my life where I felt emotions that I was unable to comprehend at the time. Seeing a family member on an operating table was the most petrifying moment that I have gone through, especially when the person on the table was my father. My father had to get a chalazion removed from his right eyelid. The doctor told my family that my father would be susceptible to certain health risks because of his diabetes and the severity of his cyst. This procedure was the hardest thing I have had to deal with in my life because it made me feel helpless. Usually, when my dad needs help he always asks me, but this time I could not do anything. It is interesting to think that something so small had such a big affect on my life.
Lauginie, P. n.d. Drummond Light, Limelight: a Device in its Time. [e-book] Université Paris-Sud, France: Groupe d’Histoire et de Diffusion des Sciences d’Orsay (GHDSO). http://archive.ihpst.net/2013/Procs/Lauginie.pdf [Accessed: 19 Jan 2014].
...onance frequency are trapped inside the cavity to ensure maximum reflection when the IDT is placed an integer number of half wavelength.
The concept of fiber optics is simple, yet it provides so many potentialities in the world of technology. Presently the world relies on fiber optical technology for its data and communications systems. The consumer can converse on the telephone and hear voices with clarity, as well as send and receive information on the Internet with ease. However, there still lay a sea of possibilities in this area of technology that has not yet been discovered.
Optical microscopy includes Fluorescence, Bright field, and phase contrast. Optical or light microscopy allows magnification of an object by the passing of visible light transmitted from the sample through a single or multiple lenses to allow a magnified view of the sample.
Spectroscopy basically involves the study of the interaction of radiated energy with matter. These different radiations could be used to study chemical and physical material properties of different atoms. Colors of light differ in wavelength and energies and when they interact with matter, the light is either scattered, reflected, transmitted, absorbed, reflected or fluorescence. The interaction makes vibrational, electronic or nuclear changes in energy levels. This difference between energy levels includes a range of electromagnetic spectrum. Types of electromagnetic radiation include gamma rays, x-rays, ultraviolet, visible, infrared, microwaves and radio wave. Energies, wavelengths, frequencies, or wave number can be used to describe the radiations.
Thomas Alva Edison is a very well-known American inventor. He invented about 1093 devices that influenced us greatly, such as light bulb, microphone, telephone receiver, universal stock ticker, phonograph, kinetoscope (used to view moving pictures), storage battery, electric pen, and mimeograph. Edison also improved many other existing devices as well. In the period from 1878 to 1880, Thomas Edison began serious research into developing a practical incandescent lamp. Edison and his associates worked on at least three thousand different theories to develop an efficient incandescent lamp. In 1878, Edison built his first high resistance incandescent electric light. Incandescent lamps make light by using electricity to heat a thin strip of material (called a filament) until it gets hot enough to glow. Many inventors had tried to perfect incandescent lamps to "sub-divide" electric light or make it smaller and weaker than it was in the existing arc lamps, which were too bright to be used for small spaces such as the rooms of a house.Edison's lamp would consist of a filament ho...
Fiber optics is a new technology that uses rays of light instead of electricity to transmit information over optical fibers at very high speeds. The optical fibers are usually thin strands of glass that are combined into cables and used to send information and computer data in the form of pulses of light. The optical fibers provide much clearer transmission than conventional copper cable and satellite links. The world market for optical fiber continues to grow rapidly, with shipments increasing 14 percent from an estimated 7.0 million kilometers of fiber in 1990 to approximately 8.0 million in 1991. The demand for multimode fiber is predicted to continue to expand through the mid-1990s, with some market analysts indicating that 15 to 20 percent annual growth over the next three years is reasonable. Strong demand is expected for singlemode and multimode fiber to be used in cables for local area networks, telecommunications, cable television (CATV), and transoceanic fiber-optic systems.
The achromatic lens that first appeared in a 1733 telescope made by Chester Moore Hall, John Hadley's production of larger paraboloidal mirrors in 1721, the process of silvering glass mirrors introduced by Léon Foucault in 1857, and the adoption of long lasting aluminized coatings on reflector mirrors in 1932 evolved the telescopes to higher levels of performance and accuracy.
Spectroscopy is measured using a spectrophotometer. A beam of light is first pointed towards the spectrophotometer. The beam of light then strikes a part of the spectrophotometer called the diffraction grating. The diffraction grating works similar to the prism shown above. It separates the light into its component wavelengths by rotating so that only a specific wavelength will reach a part of the spectrophotometer called the exit slit. On the other end of the exit slit there is a sample located in a test tube as well as a detector. After the wavelength passes through the sample, the detector measures the transmittance and absorption of the sample. The transmittance is the amount of light that was able to pass through the sample and reach the detector, and the absorption is the amount of light that was absorbed by the sample. The detector converts the measure of transmittance into s digital display, such as a graph.