1. INTRODUCTION
With the due course of properties of light, an optimum amount of the energy of the guided light is in form of evanescent waves which are very sensitive to changes occurring in the external environment, forms multilayer structural photonic band gap by propagating electromagnetic waves of certain wavelengths. The electromagnetic (EM) waves with frequencies falling within Photonic Band Gaps (PBGs) [1, 2] cannot propagate through the structure. The localized states can be created in the PBGs by introducing defects into the periodical structures. Due of their ability to control the propagation of light and the possibility of many new optical devices, PCs have been investigated intensively recently. If the PBG can reflect EM waves incident at any angle with any polarization, then an omnidirectional band gap (OBG) can be achieved with negligible loss within a specific frequency range [3-6]. It found out that one-dimensional PCs (1DPCs) may have OBGs, and the general conditions for obtaining OBGs in 1DPCs are presented in NUMERICAL METHOD and it has potential applications [7, 8], such as, omnidirectional terahertz mirrors [9], controllable switching [10], tunable polarizer [11], narrow- band filters [12], and refractometric optical sensing [13], etc.
One-dimensional ternary photonic crystals (1DTPCs) are also put forward to obtain the extended OBGs [11, 14-19]. 1DTPCs are constituted by three material layers in a period of the lattice. The wavelength range of OBGs can be enhanced by 108nm when the structure was modified by sandwiching a thin layer of ZrO2 between every two layers demonstrated by Awasthi et al [16]. When the sandwiched layer was CeF3, the enhancement in the range was 120 nm. The OBGs can be significant en...
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The use of one dimensional ternary PBG structure is not limited to enhanced refractive index sensing, but it can be further extended to enhanced temperature sensing by in filtrating the third material layer with liquid crystals, in which, refractive index changes can be thermally induced.
5. FUTURE SUGGESTIONS:
Refractometric optical sensor can be used as a index sensor for detecting adulteration of different materials as well as liquids or gases. It was observed that a slight refractive index change in material layers causes the sensing of change in refractive index of the medium through which it can easily differentiate the layers which are being changed due to their different transmission peaks or transmittivity. The sensitivity and fabrication of different compounds can be enhanced as well as monitored by the application of this sensing method.
In the French coastal town of Saint- Malo in August 1944, War World II is coming to its high point. The allies are landing and fighting against Germany. Anthony Doerr’s “All the Light We Cannot See” is a historical fiction book, with a wide-ranging language and characters who are both courageous and heartbreaking. Doerr brings together the stories of a French girl named Marie-Laure, who has lost her eyesight and a German orphan named Werner. As Hitler upsurges, Marie-Laure and Werner lives and families are torn apart by the war. Anthony Doerr 's’ use of imagery, and metaphor, he stresses the damage of life that war creates. Since the characters were affected by the war and also affected by their experiences, all characters went through a change
The book All The Light We Cannot See by Anthony Doer, was not your traditional love and war story. It’s about a young blind girl named Marie growing up in the war, who had a connection with a young boy named Werner who is a part of the Hitler youth. There are a few other characters who are all in different parts of the world, and yet they eventually all meet up together and find out they all have some type of connection between each other. All of the characters in the book were affected by the war, and caused them to change into the characters that they ended up to be.
Light travels ( in certain substances ) at a fraction of the velocity if it travelled in a vacuum. The index of refraction is the inverse of this fraction. Thus, this number is greater than or equal to 1. This index is also specific to light, so different light in different mediums have different indices. For example, here is a table of indices:
McKeegan, Noel. "Flexible metamaterials the key to a working invisibility cloak?." GIZMAG. N.p., 11 Apr. 2007. Web. 12 May. 2014. .
IC Temperature Sensors agreed that there is a major diversity of how thermal sensors read the heat, for example, a thermometer measures temperature with mercury rising as heat increases, showing the temperature on the side. However, thermometers only measure the temperature when it is close up to the heat source. Thermographic sensors are long ranged temperature measuring devices which makes them more ideal for this experiment. Thermographic sensors read the temperature using thermograms. Thermograms show a variety of different shades of color depending the temperature. The temperature is based off a number of different variables such as thermal radiation (2007). Thermal sensors that use thermography have many uses that they were created for. Thermal sensors are used in the military to detect explosives frequently. The marines use thermography to spot enemies also. Thermography is not only used by the military, it is also used for medical reasons such as detection of breast cancer (Flir Threat Detection,
This transducer senses its surroundings by emitting and/or detecting infrared radiation (invisible electromagnetic radiation with longer wavelengths than those of visible light). They can also detect the person’s skin temperature through emitted black body radiation.
In summary, a new impedimetric biosensor for hCG determination in urine has been developed. A simple approach for generating a graphene-aminated surface to which an antibody binding with a suitable orientation for antigen binding is presented. The observed resistance to electron transfer increased linearly with increasing of log(hCG) concentration. The sensor response was not affected by chemical components present in synthetic urine indicating non-specific binding.
When the light emitted from the lamp is focused on the grating, it scattered according to its wavelength. The diffraction grating angle is adjusted according to the required wavelength. Then that light passes through half mirror and it splits into two rays, one passes through reference-side light-receiving section and the other ray passes through flow cell. The difference in intensity of light can be determined between light from reference cell and flow cell, the output obtained as absorbance. UV detector detects all the components with high sensitivity. The schematic diagram of UV detector is shown in Fig.
Light is a very important factor in the rate of photosynthesis, in my project I am going to test that plants do need light in order to photosynthesise. It will be very interesting to see how light will influence the rate of photosynthesis in plants and what will happen if they do not get the required light in order to produce starch .
Kennedy, Gerry. "The Spectronics Blog." The Spectronics Blog RSS. Spectronicsinoz, 15 May 2012. Web. 04 Mar. 2014.
Refraction of Light Aim: To find a relationship between the angles of incidence and the angles of refraction by obtaining a set of readings for the angles of incidence and refraction as a light ray passes from air into perspex. Introduction: Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law. (Refer to diagram below)
Temperature is an essential parameter because the index of refraction is affected by temperature. The speed_of light in a liquid will increase when the temperature increases. For instance, according to Hanson (2006), when there is 1°C increasing_in temperature, many organic_liquids the index of refraction decreases by nearly %0.05
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.
Will the future of optics still be based on mirrors, prisms and lenses? To investigate this question some background information on the key concepts of light, reflection and refraction will be covered first. Light is defined as electromagnetic radiation of any wavelength. Light is also known as luminous energy or radiant energy. The speed of light is 299 792 458 m/s and is always constant. Electromagnetic radiation involves electromagnetic waves, radio waves, infrared, visible light, ultraviolet, x-ray and gamma ray. Electromagnetic radiation can travel through empty space unlike other waves that can only travel through substances such as solids, gases or liquids. Waves are measured in crests or troughs (see figure 1) the formula for the wavelength frequency relationship is c=f λ. Amplitude and wave frequency are both very important for reading and understanding waves. Amplitude measures the intensity of the wave by measuring the height of the wave, measuring the maximum vertical displaceme...
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...