Showing 9 results for Mach-Zehnder Interferometer
Dr. Ebrahim Safari, Somayeh Salmani Shik, Dr. Mohammad Hossein Majles Ara, Dr. Mohammad Sadegh Zakerhamidi,
year 20, Issue 0 (1-2014)
Abstract
In this paper, the Optical Bistability (OB) of 2-Methyl-4-Nitroaniline (MNA) doped with PMMA polymer thin films on Mach-Zehnder interferometer with applied external feedback are investigated in five thicknesses. The measurements were performed at 532 nm using a NdYAG CW laser with irradiation of 300 mW. A hysteresis loop due to optical bistability obtained because of charge transfer in benzene ring. It is demonstrated that the gain of optical bistability improved with using external feedback for thinner samples. But in higher thicknesses, the local thermal effect decrease the gain and has negative effect on OB.
Mr. Alireza Taghavi Nasr Abadi, Dr. Vahdat Nazerian,
year 21, Issue 0 (3-2015)
Abstract
In this paper, we present self-switching mechanism using Semiconductor Optical Amplifier (SOA)-assisted Mach-Zehnder interferometer (MZI) considering dynamic gain response of the SOA. The effect of key structural and input pulse parameters of an all-optical MZI self-switches is identified and their role in the operation of self-switch is analyzed. The optimum values of these parameters must be correctly selected and adapted so as to ensure the satisfaction of the best operating conditions. Simulation results demonstrate that key parameters must be suitably must be modified to the specific all-optical self-switching application.
Fatemeh Jafariani, Ehsn Ahadi Akhlaghi, Mohammad Avalin Charsooghi, Mohammad Taghi Tavassoly,
year 22, Issue 0 (2-2016)
Abstract
In this paper, heat transfer between a cold plane next to awire is studied. We measured phase distribution around the wire near the cold plane, using superimposing the waves diffracted from two similar wires of diameter 320 µm in a Mach-Zehnder interferometer. Also by passing electrical current through the wire, the phase distributionin this case is also determined. In this work an 8bit detector is used and achievable accuracy for phase is about π/200.
Bahare Zarefarsani, Marziye Valieghbal, Mostapha Tarkashvand, Amir Hossein Farahbod,
year 22, Issue 0 (2-2016)
Abstract
To provide the conditions for nuclear fusion by high energy and powerful laser beams, it is required to have a high degree of symmetry and surface uniformity of the spherical capsules to reduce the Rayleigh-Taylor hydrodynamic instabilities. In this paper, we have used the digital microscopic holography based on Mach-Zehnder interferometer to study the quality of targets for inertial fusion. The interferometric pattern of the target has been registered by a CCD camera and analyzed by Holovision software. The uniformity of the surface and shell thickness are investigated and measured in reconstructed image. We measured shell thickness in different zone where obtained non uniformity 22.82 percent.
Dr. Abdolah Alizadeh, Mohammad Teybinejad, Fariborz Rahimi,
year 23, Issue 0 (2-2017)
Abstract
This paper, focuses on the design and simulation of sensors capable of measuring carbon dioxide concentrations between 0.1 to 500 ppm. Carbon dioxide information at a temperature of 298 ° K and a pressure of 1 atmosphere is imported to Lumerical software for simulation. Then the sensor structure is designed based on vernier effect to select specific wavelength in the absorption spectrum of carbon dioxide. The simulated output is developed inside Lumerical using Finite-difference time-domain (FDTD) method. Sensor structure optimization and sensitivity improvement were achieved by using two distinct wavelengths of absorption for the gas, and Mach-Zehnder interferometer. The outputs were combined and prepared to enter the Detector section.
Samira Ebrahimi, Dr Masoomeh Dashtdar,
year 23, Issue 0 (2-2017)
Abstract
Interferometric microscopes are one of the most effective methods in study of micron and sub-micron sized samples including biological cells. Among the different interferometric methods, digital holographic microscopy (DHM) has a significant importance in studying the dynamics of moving samples. Recently the utilization of common-path geometries has been popular for studying the cell fluctuations because of high temporal stability and low optical path difference (OPD) difference. In this paper we present a compact, efficient and highly stable setup during each kind of mechanical, optical and environmental vibrations based on Fresnel biprism interferometry. A Diode Laser module with low coherence length was used as the source. Reconstructing the intensity and phase information is possible by using fringe analysis methods. We measured OPD variations vs. time by this configuration and compared the results with an off-axis DHM setup based on Mach-Zehnder interferometer geometry. The results illustrated the great performance and nanometer accuracy of our setup in studying the morphological changes of living cells
Gholamreza Lashkarivand, Gholamreza Honarasa, Hasan Pakarzadeh,
year 24, Issue 0 (3-2018)
Abstract
In this paper, nonlinear photon-added displaced Kerr states are introduced as the output field of a Mach-Zehnder interferometer including the Kerr medium when the input fields are the deformed photon-added coherent state and the vacuum state. As the physical realization, the presented approach is applied to the Poschl-Teller potential and their photon number distribution and Mandel parameter are studied. The results show that the introduced states can be considered as the nonclassical states.
Behdad Barahimi, Mohammad Danaei,
year 25, Issue 0 (3-2019)
Abstract
Third-order nonlinear Photonic Crystals are the most prominent all-optical switching devices. In this paper by implementing a MZI, slow light structure and making use of similar Kerr effect behavior, we have proposed an all-optical switch, capable of guiding light up to a certain intensity. The switch ceases on-state as further increase of intensity. Changing the device dimensions adjusts on/ off intensity threshold, making it possible for the designers to set dimensions and switching threshold of the switch according to the system configuration and demands. Here we would get assured of the practicality of our design.
Faezeh Akbari, Mirhossein Seyednazari, Hamid Latifi, Mohammad Esmaeil Zibaei,
year 25, Issue 0 (3-2019)
Abstract
In this article a dual-core fiber optic sensor based on mach-zehnder interferometer for measurement refractive index changing is simulated. In this structure one of the cores is doped with germanium and the other with phosphorus. They operate as interferometer arms. Since the length of both arms are equal, interference pattern is formed by the refractive index difference of cores. One of the cores is considered as reference arm and the evanescent field of the other core interacts with surrounding environment. The interference pattern shifts with changing the refractive index of the surrounding environment. The sensor sensitivity is greatly dependent on evanescent field penetration into the external medium which can be increased by chemical etching or side polishing of fiber cladding. Simulation results show that the maximum achieved sensitivity is 643.85 nm/RIU which could be used for fiber optic biosensors.
