Optical amplifications were not taken seriously, until for very long, it had been postulated in 1916 by Elbert Einstein. The ones that proposes the building of an optical amplifier is Valentin A.Fabricant, which is a Russian engineer in his unpublished 1939 dissertation. However, serious attention and interest came only after Charles Townes used stimulated emissions to produce microwave oscillations in the Maser in1954. The first laser was built in 1960 by Theodore Main. Early laser developer proposed and saw amplification as a step to build a laser. The need for optical amplifier was created by Elias Snitzer, at American Optical Correpeaters. An optical amplifier is a device which amplifies the optical signal directly without ever changing it to electricity. I t receives input signal and produces output signal with higher optical power. Usually, laser beams was the input and output, either propagating as Gaussian beams in free space or in fiber. Some applications of optical amplifiers were it can boost the average power of laser output to higher levels. Besides, it can amplify weak signal before photon detection, so that the noise detection can be reduced. There are three types of optical amplifiers which are Raman Amplifier, Semiconductor Amplifier, and Rare Earth-doped Fiber Amplifiers. Raman Amplifier, also known as Distributed Amplifier, is a nonlinear effect in fiber-optical transmission that results in signal amplification if optical pump waves with the correct wavelength and power are launched into the fiber . In order to create optical gain, Raman optical amplifier utilize Raman scattering, often called SRS- Stimulated Raman Scattering. One of the most interesting developments is the usage of Raman effects in opt... ... middle of paper ... ...iber. The concentrations of Rare Earth, RE2O3 is typically low. One types of Rare Earth Amplifier that most important technologically is Erbium Doped Fiber Amplifier, EDFA. EDFA is a fiber segments, a few meters long, which is heavily doped with Erbium, Er3+. It was usually pump by semiconductor laser at 980 nm. However, as 1480 nm pump is available, pump can co propagate with the signal since silica fiber has low loss. Therefore, in this project, the Erbium Doped Fiber Amplifier will be used to observe and obtain power gain and noise figure of M-12 Fibercore. Gain can be defined as ratio of output power to input power. Gain is measured in unit decibel, dB. The power gain equation can be expressed by: Gain=10 log P_out/P_in ,dB Meanwhile, noise figure is the measures of degradation of the signal-to-noise ratio caused by components in a radio frequency signal chain.
quantum noise for each every image. When the quantum noise is increased by increasing the
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.
The desired product is a white crystalline solid which indicates that it does not have an absorption band around 400-800nm, thus suggests that the compound absorbs shorter wavelengths. Whether the system is conjugated must be evaluated by TLC using the short wavelength of 254 nm.
Inelastic scattering of light by elementary excitations such as phonons and plasmon in the material is termed as Raman scattering. When a beam of light (UV-Visible and IR region) of frequencyI is incident on a solid, most of the light gets scattered elastically, i.e., without change in energy. A small fraction of light is scattered inelastically with frequencies I ± m, where m are the characteristic vibrational frequencies of the e- cloud in the molecule/solid.
Magnifying power: is also called angular magnification. Figure 1a shows an object y in front of a lens. Rays of light reflect off the object through the lens and a now larger image, y', of y can be seen. Once, the image is brought further from the lens, as in figure 1b, the image, y', is even larger. (So as to no discrepency: in figures 1a and 1b, the observer is on the right of the lens looking towards the image y')
Therefore, the lowest value that can be detected by the technique is 28.17mg/kg. The table shows that the lowest permitted level of cyclamate in foods is 400mg/kg. This far exceeds the 28.17mg/kg limit so this value can be detected by the technique, as will all other maximum permitted levels of cyclamate in foods. Because of this, the method will be useful.
Birefringent polarizers: inside materials with birefringent properties beam splits into ordinary and extraordinary ray, each ray have a different index of refraction.
Kennedy, Gerry. "The Spectronics Blog." The Spectronics Blog RSS. Spectronicsinoz, 15 May 2012. Web. 04 Mar. 2014.
Most people don't know where the idea of the laser came from. The idea for the laser came from a machine called a maser. The maser was a tool that was able to strengthen, or amplify radio and light waves. The first laser was made in California in 1960. It was built by Theodore Maiman along with a group of American scientists. The material they used for a concentrator was a man- made ruby. This was done by, coiling a simple flash tube around a rod, and beaming powerful flashes of light at it. The result was pulses of red laser light. Once they made the device they had to name it. They had think of some word or words to described it. They came up with Light Amplification by Stimulated Emission of Radiation. Using the first letter of each main word they named it laser. The laser had everyone excited.
LIDAR, stands for Light Detection And Ranging, is an active optical remote sensing instrument. It is an innovative technique that uses laser for probing the planetary atmosphere [1, 2, and 3]. Atmospheric LIDARs use narrow pulsed lasers. Flash-lamp pumping is generally employed in generation of Q-switched lasers. Flash-lamp pumped (FLP) systems produce lasers at low repetition rate with high pulse energies. Several problems such as limited life-time of flash-lamp and requirement of pump motors for driving deionised (DI) water to cool the laser cavities limit the applications of FLP systems in strategic fields. Recent technologies employ semiconductor diodes as pump sources for solid-state lasing materials. These units built-in with accousto-optic modulator (AOM) produce pulse modulation in laser at high repetition rates. Diode pumped solid-state (DPSS) lasers offer several advantages over conventional FLP types. DPSS lasers generate radiations in Infrared (IR), visible and ultraviolet (UV) spectral bands. The commercially available DPSS lasers offer features as high pulse repetition rate, excellent beam profile, compact size, narrow pulsing, good spectral purity, long-life and stable output. Moreover, DPSS lasers operate with air cooling.
To prevent the higher amount of evaporation caused by the moisture content, food samples must be put into the desiccator to take the correct results.
The magnifying glass is one of the earliest devices known that is for optical uses. Ancient Egyptians used shards of crystal or diamond to view abject better. During the reign of Emperor Nero, (37 A.D - 68 A.D) was known to look through an emerald at actors that were on stage, this was so that he could get a better view of them. The first known magnifying glass to be developed
In the conventional pulse oximetry we have 2 LED lights, Red and Infrared both having wavelengths of 660nm and 940nm respectively.
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, in the world of technology, is used to carry voice, data, and video inside these strands of glass. Optical fiber for telecommunications consists of three components: core, cladding and coating. The core is the central region of an optical fiber through which light is transmitted. The core and cladding are manufactured together as a single piece of glass and cannot be separated from one another. The third section is the outer protective coating. This coating is typically an ultraviolet (UV) light-cured acrylic applied during t...