- 标题
- 摘要
- 关键词
- 实验方案
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Experimental Demonstration of Single Sideband Modulation Utilizing Monolithic Integrated Injection Locked DFB Laser
摘要： Single sideband (SSB) modulation based on a monolithic integrated optically injection-locked (MOIL) DFB laser is demonstrated experimentally. To our knowledge, this is the first time to realize SSB modulation utilizing a MOIL DFB laser. Tunable SSB signals with large lower-to-upper sideband power ratios are achieved by changing the bias currents of the MOIL DFB laser. The largest lower-to-upper sideband power ratio is measured to be 24.4 dB, which is very useful for improving the transmission performance of a radio-over-fiber link. Due to the generated SSB modulation, the fiber transmission response is flattened significantly and a signal of 25 GHz is transmitted through 85-km fiber without being affected by the fiber chromatic dispersion. 20 MSymbol/s 32-QAM signals with subcarriers of 21 GHz, 23 GHz and 25 GHz are also transmitted by the proposed SSB modulation link, and both the error vector magnitude (EVM) and the bit error rate (BER) of the link are improved distinctly. The proposed method can effectively suppress the fiber chromatic dispersion.
关键词： optical photonic integration,Single sideband modulation (SSB),injection-locked DFB laser,fiber chromatic dispersion
更新于2025-09-16 10:30:52
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Adaptive Equalization for Dispersion Mitigation in Multi-Channel Optical Communication Networks
摘要： Optical communication networks (OCNs) provide promising and cost-effective support for the ultra-fast broadband solutions, thus enabling them to address the ever growing demands of telecommunication industry such as high capacity and end users’ data rate. OCNs are used in both wired and wireless access networks as they offer many advantages over conventional copper wire transmission such as low power consumption, low cost, ultra-high bandwidth, and high transmission rates. Channel effects caused by light propagation through the fiber limits the performance, hence the data rate of the overall transmission. To achieve the maximum performance gain in terms of transmission rate through the OCN, an optical downlink system is investigated in this paper using feed forward equalizer (FFE) along with decision feedback equalizer (DFE). The simulation results show that the proposed technique plays a key role in dispersion mitigation in multi-channel optical transmission to uphold multi-Gb/s transmission. Moreover, bit error rate (BER) and quality factor (Q-factor) below 10?5 and above 5, respectively, are achieved with electrical domain equalizers for the OCN in the presence of multiple distortion effects showing the effectiveness of the proposed adaptive equalization techniques.
关键词： decision feedback equalizer,polarization mode dispersion,chromatic dispersion,feed forward equalizer,optical communication networks
更新于2025-09-12 10:27:22
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Nonlinear Fiber Optics || Introduction
摘要： This introductory chapter is intended to provide an overview of the fiber characteristics that are important for understanding the nonlinear effects discussed in later chapters. Section 1.1 provides a historical perspective on the progress in the field of fiber optics. Section 1.2 discusses various fiber properties such as optical loss, chromatic dispersion, and birefringence. Particular attention is paid to chromatic dispersion because of its importance in the study of nonlinear effects probed by using ultrashort optical pulses. Section 1.3 introduces various nonlinear effects resulting from the intensity dependence of the refractive index and stimulated inelastic scattering. Among the nonlinear effects that have been studied extensively using optical fibers as a nonlinear medium are self-phase modulation, cross-phase modulation, four-wave mixing, stimulated Raman scattering, and stimulated Brillouin scattering. Each of these effects is considered in detail in separate chapters. Section 1.4 gives an overview of how this book is organized for discussing such a wide variety of nonlinear effects in optical fibers.
关键词： fiber optics,stimulated Raman scattering,four-wave mixing,stimulated Brillouin scattering,chromatic dispersion,nonlinear effects,self-phase modulation,cross-phase modulation,birefringence
更新于2025-09-12 10:27:22
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Chromatic Dispersion Estimation Based on CAZAC Sequence for Optical Fiber Communication Systems
摘要： We propose a chromatic dispersion (CD) estimation method based on constant amplitude zero-autocorrelation (CAZAC) sequence and fractional Fourier transform (FrFT) algorithm for optical fiber communication systems, which extends the application of CAZAC sequence. By applying FrFT on the CAZAC sequence signal, the optimal order is searched and employed to estimate the accumulated CD because that the CAZAC sequence shares similar properties with chirp signal. We demonstrate the feasibility of the proposed method by the simulation of a 28 GBaud polarization-division-multiplexed (PDM) quadrature phase-shift keying (QPSK) optical fiber communication system. The error of CD estimation is less than 70 ps/nm for the standard single mode fiber (SSMF) link of 2000 km with OSNR in the range of 10-20 dB and the launch power in the range of 0-4 dBm per channel in a five channel system. It shows that the method is robust to ASE noise and optical fiber nonlinearity. Furthermore, the proposed method has been experimentally verified with the error of CD estimation less than 50 ps/nm after 100-900 km fiber link transmission.
关键词： Chromatic dispersion,fiber optics systems,CAZAC sequence,fractional domain.
更新于2025-09-11 14:15:04
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Polarization Modulation Instability in All-Normal Dispersion Microstructured Optical Fibers With Quasi-Continuous Pump
摘要： We report the experimental observation of the polarization modulation instability (PMI) effect in all-normal dispersion (ANDi) microstructured optical ?bers (MOFs) with quasi-continuous pumping. The small unintentional birefringence (～10?5), that any realistic non-polarization maintaining MOF exhibits, contributes to this nonlinear effect. PMI can produce two sidebands whose polarization state is orthogonal to the polarization of the pump. In this work, only one type of PMI process is observed, i.e., when the pump is polarized along the slow axis of the ?ber and sidebands are generated in the fast axis mode. This PMI process was studied experimentally in two ANDi ?bers with different dispersion features and pumped with long (700 ps) pump pulses at 1064 nm. Experimental results are compared with theoretical calculations, with reasonably good agreement.
关键词： Four-wave mixing,Optical polarization.,Microstructured optical ?bers,Chromatic dispersion,Fiber nonlinear optics
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID) - Miramar Beach, FL, USA (2019.8.19-2019.8.21)] 2019 IEEE Research and Applications of Photonics in Defense Conference (RAPID) - Study of 90-GHz Phased Array Antenna System Based on Chromatic Dispersion Effect in the Optical Fiber
摘要： Phased array antenna system is evaluated in the 90-GHz band using fiber-dispersion-based true time delay. Phase differences are induced by transmission of the optical fiber, without any additional equipment. Beam steering angle with a range of 5 degrees is successfully demonstrated with four horn-antenna elements.
关键词： phased array antenna,radio over fiber,fiber chromatic dispersion,millimeter-wave
更新于2025-09-11 14:15:04
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Demonstration of a Sub-GHz flat-top RF-Photonic Filter Enabled by Fourth-order Dispersion Compensation
摘要： We demonstrate a sub-GHz RF-photonic filter based on phase and amplitude control of a wideband all-fiber frequency parametric comb with 25-GHz tone spacing. The narrow bandwidth filter construction based on 221 comb tones was enabled by fourth-order dispersion compensation of the dispersive element. The filter integrity was further tested by retrieval of a set of digital modulated RF channels.
关键词： Chromatic dispersion,Microwave photonics,Optical signal processing,Finite impulse response filters
更新于2025-09-11 14:15:04
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Stable Low-Repetition-Rate Time-Lens Picosecond Seed Source
摘要： The design and performance of a sub-10-picosecond source based on temporal focusing implemented with a lithium niobate phase modulator and a grating compressor are presented. The source is optimized taking into account spectral gain narrowing in subsequent amplifiers. It advantageously delivers low-repetition-rate pulses with tunable pulse duration, and its short-term jitter and long-term drift over extended periods of time are of the order of a few picoseconds.
关键词： Chromatic dispersion,pulse compression methods,phase modulation,optical pulse generation
更新于2025-09-11 14:15:04
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Signal Processing for Fiber Optic Systems
摘要： This paper reviews the digital signal processing (DSP) methods used in coherent fiber optic communication systems. With the advances in high speed DSP, linear impairments such as chromatic dispersion (CD) and polarization mode dispersion (PMD) can be compensated for using fixed/adaptive equalizers. It is also possible to compensate for the interplay between dispersion and nonlinearity by digital back propagation (DBP), in which the virtual fibers whose signs of dispersion, loss and nonlinear coefficients are opposite of those of the transmission fiber, are realized in the digital domain by numerically solving the nonlinear Schr?dinger equation (NLSE). DSP equalization enhances the transmission performance and error-free reach of coherent fiber optic systems significantly.
关键词： Chromatic dispersion,nonlinear fiber optics,digital signal processing,fiber optic communications,perturbation techniques,polarization mode dispersion,digital back propagation,coherent communications
更新于2025-09-10 09:29:36
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Effective method for determining chromatic dispersion from a spectral interferogram
摘要： We present a novel method for determining chromatic dispersion profile from a broadband spectral interferogram obtained by using a white-light interferometry technique. The proposed method is based on direct calculations of a second derivative of the registered spectral intensity at extremal points which in result gives a spectral phase difference derivative further used for dispersion determining. Although the method is best suited for processing interferograms with modulation around a zero level (zero-mean value interferograms) and slowly changing envelope, the conducted numerical tests show that it is highly tolerable to different types of perturbations of the input interference signal. The proposed method can be applied both to spectral interferograms with monotonically changing phase difference as well as containing stationary phase difference points. We demonstrate the effectiveness and accuracy of the proposed method in measurements of chromatic dispersion of commercially available samples like the BK7 glass plate and the Corning SMF-28 optical fiber.
关键词： chromatic dispersion,optical interferometry,Optical fiber dispersion
更新于2025-09-04 15:30:14