Fiber Grating Filters and Optical Switching Module Applications

• Main Authors: Tzuoh-Chyau Yeh, 葉作球
• Other Authors: Hung-Chun Chang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/26284024675437117063

碩士 === 國立臺灣大學 === 電信工程學研究所 === 100 === A single-mode fiber becomes a multimode fiber when cladding2 is added outside cladding1. The addition of cladding2 supports new applications, such as new long-period fiber gratings. Coupled Mode Theory and Transfer Matrix are principal to design and simulation fiber gratings. Types fiber grating are useful in modern optical communication. CDMA codeword could be map to wavelengths. That’s why optical CDMA switching works. Large bandwidth and high speed switch rate are meet characters of future telecommunication network requirements. Light with a wavelength of 1310 nm wavelength is generated by a laser, and is coupled into SMF for traditional optical fiber communication. The lowest loss wavelength band of the SMF, which is around 1550 nm, is favored for telecommunication. The band from 1300 to 1620 nm of wavelength is in fact used for modern optical fiber communication. A bandwidth over 40 THz is available utilized. The full use of a sectionalized band is an issue of concern. Sectionalized bands satisfy Optical Code Division Multiple Access requirements. A white light source is modulated by user data and passed through the OCDMA coder. The white light source replaces a laser which is a narrow-band light source, for CDMA systems. The huge signal bandwidth and low loss of optical fibers are of particular interest to optical communication engineers because of their potential importance in fiber optical applications. Studies of dynamic adjustable bandwidth and usage in each channel of a DWDM and OCDMA are advanced. Optical fiber signal process approaches can realize the optical fiber grating for filtering multiple wavelengths. Several methods can be utilized to make various gratings that can function as filters. These include Bragg gratings, chirped gratings, long-period gratings, Gaussian apodization gratings, phase-shift gratings, superstructure gratings and others. These are good for tailoring gratings with complicated superstructures. These investigate optical fiber grating for filtering multiple wavelengths. Step by step present to develop the long-period fiber grating multiple wavelength filters was described in this text. Examples are considered to help understand fiber gratings and LPFG can be used in the development of multiple-wavelength filters. The first on the world with LPFG which cladding2 is added outside cladding1 is made of single-mode fiber and application of OCDMA 8X8 switching is realized using multiple-wavelength filtering of LPFG, as well as CDMA Optical Ethernet Adjacent Fiber Module works with duplex and half duplex mode simultaneously and OCDMA Expansion Connector of PC mother board. They are described in appendixes in this thesis.