The primary contributions of this dissertation are the study of common nonreciprocal optical effects and demonstration of several basic applications to fiber components and fiber metrology systems. Polarization independent isolators and wavelength division multiplexers were also realized by employing suitable nonreciprocal effects and were discussed in chapter 2 and chapter 4, and their feasibilities were verified by experiment. worth stressing that an isolator has to block or divert all the modes that can be excited for the backward transmission. A variable-loop Sagnac interferometer was designed and applied to distributed sensing in chapter 6, and the reciprocity-insensitive property of the Sagnac interferometer was preserved. the scattering matrix of an isolator the scattering matrix must be asymmetric, because opposite propagation directions have different mode-to-mode transmissions. The performance of the intensity-based reciprocity-insensitive structure (IRIS) was employed successfully in a fiber optic current sensor for stabilizing the signal from birefringence influences in chapter 5. Several reciprocity-insensitive structures designed and analyzed in chapter 3. Fortunately, most optical signals can be classified into intensity-based and phase-based systems, and the Jones matrix technique is the ideal tool for describing the intensity-based system. The major difficulty in forming a general optical network theory is the complexity of optical signals compared to the electrical signal, because each light signal consists of four independent parameters, all of which changing during transmission.
The best-known application of nonreciprocity to optical components is the isolator, and the known nonreciprocity-based fiber optic sensors are the fiber optic gyroscope and the fiber optic current sensor. The common optical nonreciprocal phenomena include the Faraday effect, Sagnac effect, Fresnel drag effect, nonlinearity or asymmetric geometric structure-induced nonreciprocity, and some pseudo nonreciprocity. Several common nonreciprocal optical effects studied in this disseration and several basic applications to fiber components and fiber optic metrology systems analyzed. Lightwave systems, including fiber optic and integrated optic, are becoming more and more complex, new function blocks ( or components) and networking strategies are very important for future highly integrated lightwave circuits. Unlike electronic networks theory, optical network theory is still a field to be investigated. Big or small to angle error with fiber axes will lead to IL~(Omega) -, IS~(Omega) + graphs towards horizontal left of right to displacement, moreover, add or reducing to fiber attenuation will bring about IL~(Omega) -, IS~(Omega) + plots along vertical up or down to shift.Nonreciprocity is a fundamental property of networks. 2 the product of the Jones matrices of the quarter-wave plates and the rotator: J J/4(/2)R(). If (Omega) + or (Delta) (theta) are 0.573 degree(s), 0.181 degree(s) and 0.057 degree(s) angle off, IS values have a size of 40dB, 50dB and 50dB, respectively. The Jones matrix J for such a sequence can be given by. While those angle error in PM fiber is increase, IL data become large, yet IS data change small. The results are shown: under ideal condition when optical fiber are non-loss and aiming, IL and IS take (Omega) + and (Omega) - as symmetrical axes, this moment, IL value is minimum, but IS value is maximum. The manipulation and characterization of light polarization states are essential for many applications in quantum communication and computing, spectroscopy, bioinspired navigation, and imaging.
The curves of variation of IL IS with relative angle of deviation between nonreciprocal Faraday rotator and non-magnetic rotator as well as PM fiber axes non-aim are given.
Analysis of optical properties for all-fiber isolator with maintained polarization Analysis of optical properties for all-fiber isolator with maintained polarizationīy using method of Jones matrix, we analyze all-fiber isolator with polarization maintaining (PM) for optic transmission properties in this paper, the calculated formulas for insertion loss (IL) and backward isolation (IS) can be obtained.
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