Optical Demultiplexer by Using In-Line Fiber Filter.

The signal pulses will be broadened through the fiber and so we need a very sharp cutoff filters with demultiplexers. The in-line fiber filter becomes the appropriate filters. Most of these demultiplexers used after erbium-doped fiber amplifier (EDFA) which need a sharp wavelength bandpass filter (BPF) to filter out wavelengths other than the signal wavelength Exact analysis of in-line fiber filter is occurred by derive a polynomial expression for the dopant ratios of GeO2 and P2O5. The refractive index of silica doped either GeO2 or P2O5 is defined as a function of both the wavelength and the dopant ratio. The calculations of the dopant ratios of the pair materials (GeO2 and P2O5) are done at a specific filter cutoff wavelength (λc) for both high pass filter (HPF) and low pass filter (LPF). Two in-line fiber filters (HPF and LPF) are cascaded to make a sharp bandpass filter (BPF). The length of in- line fiber filter must be very short to overcome the weak of the propagation constsnt throuh it. The normalized frequency is discused. A theoritical 8-channels demultiplexer is done. The design of demultiplexer becomes very easy. [ABSTRACT FROM AUTHOR]

Copyright of Delta University Scientific Journal is the property of Association of Arab Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)