In this paper, we present an electro-optical modulator based on graphene absorption. In this structure, graphene is placed on aluminum oxide, the structure of which is repeated alternately. This alternating structure of graphene on aluminum oxide is located inside a sem More
In this paper, we present an electro-optical modulator based on graphene absorption. In this structure, graphene is placed on aluminum oxide, the structure of which is repeated alternately. This alternating structure of graphene on aluminum oxide is located inside a semi-cylindrical cavity in a 1-dimensional photonic crystal nanobeam cavity. Unlike previous articles, which consisted of cylinder holes and different areas in the nanobeam cavity is formed by changing the radius of the holes, in this structure, semi-cylinder holes have been used and, different areas are formed by rotating these semi-cylinders. This type of crystal photonics has a high quality factor. Also, this type of modulator requires little space after construction, so they are a very good option for integrated circuits. In this paper, three-dimensional finite-difference time-domain method is used for analysis. In this modulator, it is observed that by changing the bias voltage, the amount of absorption peak and also its resonance wavelength are changed. As a result of these changes, we achieve a modulation depth of about 7dB. Our proposed structure can have potential applications in integrated optical circuits, especially in telecommunication frequencies.
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In general, photonic crystals are structures of materials whose electrical and magnetic permeability changes periodically in one, two, or three dimensions. When such structures are exposed to radiation of a beam with a wavelength comparable to the period of crystal spat More
In general, photonic crystals are structures of materials whose electrical and magnetic permeability changes periodically in one, two, or three dimensions. When such structures are exposed to radiation of a beam with a wavelength comparable to the period of crystal spatial rotation, two modes occur.
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Refractive index sensors are one of the most widely used sensors in the bioelectronics and optoelectronics industries. The use of materials and structures that can detect the refractive index of unknown materials has important applications in biochemistry and medical en More
Refractive index sensors are one of the most widely used sensors in the bioelectronics and optoelectronics industries. The use of materials and structures that can detect the refractive index of unknown materials has important applications in biochemistry and medical engineering. In this paper, a polymer-based dual-core photon crystal fiber is introduced to measure the refractive index of a fluid. The size of the holes of the analyte cores and the light-transmitting solid core are engineered to be able to pass the main single mode. Due to its cheapness, high mechanical ability and ease of fabrication, the photon crystal fiber substrate is made of PMMA polymer. After simulating the structure and using the existing mathematical relations and examining the diffusion modes, for the complete transfer of light from the solid core to the core of the analyte channel, a fiber length of 0.13 cm has been obtained. The simulation results show that for a refractive index of 1.44, a sensitivity value of 1000 and a detection limit can be achieved by this sensor. All simulation steps in the field of FDTD are obtained in Lumerical software.
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In this research, a new structure of photonic crystal fibers(PCFs) will be proposed,in which instead of using the aire- holes in the cladding region, the flourine(2%) doped solid silica rods in order to reduce the problems associated with deformities of air-holes in the More
In this research, a new structure of photonic crystal fibers(PCFs) will be proposed,in which instead of using the aire- holes in the cladding region, the flourine(2%) doped solid silica rods in order to reduce the problems associated with deformities of air-holes in the cladding region will be used.Also, in the following, a few of the propagation charactristics of the proposed Photonic Crystal Fiber with a conventional silica Photonic Crystal Fiber such as, Normalized frequency,effective refractive index,total dispersion and higher order dispersions ( Group velocity dispersion and Third Order Dispersion) will be analyzed and compared. Finally it will be observed that, the proposed PCF structure is much simpler than the conventional one in the fabrication process. But they are not suitable for femtosecond solitons propagation .Also, it will be shown that, the situation of the conventional Photonic Crystal Fiber is much better than the proposed structure in the femtosecond optical solitons propagation.
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