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
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:
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.
McKeegan, Noel. "Flexible metamaterials the key to a working invisibility cloak?." GIZMAG. N.p., 11 Apr. 2007. Web. 12 May. 2014. .
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 many cases, freewill is either present or non existent in children. During world war two, many children in Germany were deprived of their free will, and when the war was over, many German citizens were left scrambling to find freewill again. In All the Light We Cannot See by Anthony Doerr, one of the main characters, Werner, struggles with finding his voice and his freewill within a Hitler youth training school. During his experience there, he stands by and watches as one of his only friends is bullied and in the end left as a shell of his existence. Werner struggles with what he should of done and if it really is beneficial to blend in with the rest of the boys at the school; while Werner may recognize his wrongdoings and the wrongdoings of others, he feels
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.
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.
Rene Descartes’ natural light is his saving grace, and not Achilles’ heel. Descartes incorporates the concept of natural light within his epistemology in order to establish the possibility of knowing things completely without doubt. In fact whatever is revealed to the meditator via the natural light is considered to be indefeasible. The warrant for the truth of these ideas does not rely on experience or the senses. Rather the truth of the idea depends on viewing the concept through clear and distinct perception. Descartes’ “I am, I exist”, (Med. 2, AT 7:25) or the ‘cogito’ is meant to serve as the basis for knowing things through clear and distinct perception. Descartes’ cogito is the first item of knowledge, although one may doubt such things as the existence of the body, one cannot doubt their ability to think. This is demonstrated in that by attempting to doubt one’s ability to think, one is engaging in the action of thought, thus proving that thinking is immune to doubt. With this first item of knowledge Descartes can proceed with his discussion of the possibility of unshakeable knowledge. However, Descartes runs into some difficulty when natural light collides with the possibility of an evil genie bent on deceiving the meditator thus putting once thought concrete truths into doubt. Through an analysis of the concept of natural light I
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 .
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.
Scientists and engineers have been able to enhance our lifestyles by understanding and using the Laws, Concepts and Principles of Optics and how they are applied in Optical Instruments. The key concepts are:
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.
Tadao Ando is an architect of light, a master of space, and a builder for mankind. His work, realized primarily in precisely finished reinforced concrete, unifies building and nature to create a deep sense of sanctuary. Ando was born in Osaka, Japan in 1941. From the age of 10 to 17, he was employed as a carpenter, learning to work in wood in the Japanese tradition. His interest in architecture began when he obtained a book of Le Corbusier sketches when he was about 18. Ando is a self-taught architect. He apprenticed for brief periods with local designers and city planners, but primarily developed his skills by reading extensively, studying Japanese shrines, temples and tea houses, and making study
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