Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: A Novel Optical Vector Spectral Analysis Technique Employing a Limited-Bandwidth Detector | EURASIP Journal on Applied Signal Processing 2005 10 1566-1573 2005 Hindawi Publishing Corporation A Novel Optical Vector Spectral Analysis Technique Employing a Limited-Bandwidth Detector C. K. Madsen Department of Electrical Engineering Texas A M University College Station TX 77843 USA Email cmadsen@ Received 23 April 2004 Revised 6 December 2004 A new technique for obtaining frequency-dependent magnitude and phase information across an optical channel is presented using tunable allpass optical filters and a detector with a small bandwidth relative to the full channel width. This technique has application to optical monitoring of intersymbol interference distortions including chromatic and polarization-mode dispersion effects and thus can provide vector information for input to the control of adaptive optical filters. A method for generating a test signal spanning the spectrum of a modulated data signal without introducing intersymbol interference is discussed. This technique can also be used to characterize an optical pulse source and does not scale in complexity or cost as the bandwidth of the source increases. Keywords and phrases intersymbol interference chromatic and polarization-mode dispersion optical channel monitoring optical channel estimation. 1. INTRODUCTION A novel optical vector spectral analysis OVSA technique is proposed that measures the phase and amplitude of a signal using a detector having a limited bandwidth with respect to the full signal bandwidth. When a known signal with spectral components spanning the channel width is launched into a wavelength-division-multiplexed WDM optical communication system it allows the frequency response of the system across the channel bandwidth to be determined. Given the importance of chromatic dispersion and polarizationmode dispersion PMD in high-bitrate optical communication systems the OVSA can be implemented to characterize both the frequency-dependent relative phase and the signal s .
