2.6.2.2 Waveguide Dispersion
The effective index varies with wavelength not only due to of material dispersion, but also because varies with . In turn, it varies with wavelengths. These implicit variations of [ ] with gives rise to the second cause for chromatic dispersion, which is term waveguide dispersive [D37]. The total dispersive are combinations of the relative contributions of waveguide dispersion and material dispersion for a conventional single-mode fibers. The zero-dispersive wavelength may be shifted to a higher value by controlling the waveguide contribution [50]. It is possible to design fibers such that is shift into the vicinity of 1.55 , such fibers are referred to as dispersive-shifted fibers (DSFs) . The
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When different polarization components of an optical signal experience different indices of refractive, they propagate with different velocities, causing pulse broadening and dispersion. These effect are known as polarization mode dispersion (PMD). PMD are a basic properties of single mode fibers that affects the magnitude of the transmission rate [D191]. Time domain effects of PMD in a shorter fibers length with a pulses being launched with equal powers on the two birefringent axes, x and y, become two pulses at the output separate by the differential group delay (DGD) see Fig.(2.9) …show more content…
The variation of power within the channel causes changes in the refractive index [D305]. By changing the refractive index, the phase velocity of light changes and the optical field acc-
-umulates an extra phase shift. This effect is known as SPM since light causes a phase change on itself [DH96]. SPM refers to the selinduced phase shift experienced by an optical field during its propagation in optical fibers. The intensity-dependent nonlinear phase shift [D305] In XPM, the refractive index changes due to variations in power not only in the observed channel but also due to variation in powers of other wavelength channels leading to the pulse distortion [D305]. Changes in the refractive index and phase shifts can also be created by a second optical field which is either at a different wavelength or on a different polarization. This type of interaction is called XPM. Such optically-induced phase shifts used in several types of interferometric and dual-mode structures for optical switching [DH96].
2.8
The analyzed yellow#5 wavelength was determined to 395nm because the actual wavelength 427nm was restricted in the Micro lab. The R2 value of the graph is 0.9827, and the level of data accuracy it indicated extremely weak data correlation. The first one dilution data points excluded from the standard curve because the point is not in the linear curve. The first concentration and absorbance value are the highest point in the graph that cannot connect as linear with another data point. After removing the first data point, the standard curve is clear and make
Zipser, K., Lamme, V. A. F., & Schiller, P. H. (1996). Contextual modulation in primary
The Big Bang theory is a theory that states that the universe originated as a single mass, which subsequently exploded. The entire universe was once all in a hot and dense ball, but about 20 million years ago, it exploded. This explosion hurled material all over the place and all mater and space was created at that point in time. The gas that was hurled out cooled and became our stellar system. A red shift is a shift towards longer wavelengths of celestial objects. An example of this is the "Doppler shift." Doppler shift is what makes a car sound lower-pitched as it moves further away. As it turns out, a special version of this everyday life effect applies to light as well. If an astronomical object is moving away from the Earth, its light will be shifted to longer (red) wavelengths. This is significant because this theory indicates the speed of recession of galaxies and the distances between galaxies.
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.
Step 2: The absorbance (A) is defined via the incident intensity Io and transmitted intensity I
capture the full effect of light during this short period of the day with the study
In September 1959 DiVita asked 2nd Lt. Richard Sturzebecher if he knew of a way to produce a strong glass fiber that would be capable of carrying a light signal. Sturzebecher had melted 3 triaxil glass systems together for his senior exam at Alfred University. In his exam, Sturzebecher had used SiO2, a glass powder produced by Corning. Whenever he had tried to look at the substance through a microscope he would end up with headache. Sturzebecher realized that these headaches came from the high amounts of white light produced from the microscopes light that was reflected through the eyepiece via the SiO2. SiO2 would be an ideal substance for transmitting strong light signals if it could be developed into a strong fibre.
3) Stokes shift - Generally the emitted fluorescent light has a longer wavelength and lower energy than the absorbed light. This phenomenon is known as Stokes shift. It is due to the loss of energy between the time a photon is absorbed and when it is emitted.
Refraction occurs when light travels from one medium crosses a boundary and enters another medium of different properties. For example, light traveling from air to water. The amount of refraction (or bending) can be calculated using Snell's Law.
The index of refraction is defined as the speed of light in vacuum divided by the speed of light in the medium. In this experiment, the index of refraction for the perspex is 1.50. Snell's Law relates the indices of refraction of the two media to the directions of propagation in terms of the angles to the normal. It refers to the relationship between the different angles of light as it passes from one transparent medium to another. When light passes from one transparent medium to another, it bends according to Snell's law which states: [IMAGE] where: n1 is the refractive index of the medium the light is leaving, n2 is the refractive index of the medium the light is entering, sin 2 is the is the incident angle between the light ray and the normal to the medium to medium interface, sin 1 is the refractive angle between the light ray and the normal to the medium to medium interface.
Now in order to understand how lights is able to be refracted in different angles, it is important to understand the Snell’s Law which states that, the refractive angle always depend on the refractive index of both media. Now, the refractive index keeps on changing depending on the wavelength of the light passing through. Light, as we know, it is a wave that has different wavelength. Each wavelength represents a different color. Thus, different colors will have different refractive index when passed through the same media. It is important to note that light is normally refracted twice when it travels through a prism, first on its way in, and when it is going back.
As a graduate student, I will undertake research and coursework in Electrical Engineering to enhance my competencies in this field. I intend to complete my master's degree in order to pursue my doctorate. The research that I am most interested in pursuing at Northeastern University surrounds the optical properties of MEMS devices, and the development of substrate-based fast electro-optical interfaces. My interest in this area stems from my undergraduate study in MEMs development for tri-axial accelerometers.
Refraction is a process that occurs when light travels between media of different optical density. Light travels at a speed of roughly 3.0 × 108ms-1 in a vacuum. A vacuum has a refractive index n=1.00. The speed at which the light is travelling will decrease as it moves into differently optically