Optical Fiber Networks for Remote Fiber Optic Sensors

This paper presents an overview of optical fiber sensor networks for remote sensing. Firstly, the state of the art of remote fiber sensor systems has been considered. We have summarized the great evolution of these systems in recent years; this progress confirms that fiber-optic remote sensing is a promising technology with a wide field of practical applications. Afterwards, the most representative remote fiber-optic sensor systems are briefly explained, discussing their schemes, challenges, pros and cons. Finally, a synopsis of the main factors to take into consideration in the design of a remote sensor system is gathered

Multiwavelength fiber laser based on different types of semiconductor optical amplifiers

Communication system in optical fiber technology has emerged as a demanding field especially for the new dense wavelength-division multiplexed (DWDM) system wherein many functional applications and basic laser system are included. The generation of multiple laser lines in multiwavelength fiber laser (MWFL) is significant in semiconductor optical amplifier (SOA) device utilization as a medium of gain to achieve a flat laser spectrum. Apart from Erbium-doped fiber amplifier (EDFA) and Raman amplification that have high mode competition and high pumping power respectively, MWFL configuration has delegated SOA due to its special inhomogeneous characteristic as a device of stability compared to other devices of scattering and amplification effects. An investigation on the types of different wideband travelling wave (TW) SOA with parameters such as optical gain, output power, noise figure (NF) and amplified spontaneous emission (ASE) noise and bias current was carried out through OptiSystem and MATLAB software and then verified by benchtop experiments. Linear SOA had the most flat gain with low NF and ASE pattern at input power -30 dBm compared with nonlinear SOA. A practical Lyot-combed and fiber Bragg grating (FBG) were constructed using unidirectional single cavity in different types of SOA and linear SOA displayed the flattest peak powers. Multiwavelength spectrum from linear, nonlinear SOA and booster optical amplifier (BOA) were varied by intensity, polarization angle (PA), in-line polarizer and time stability by applying performance evaluator such as the number of laser lines, extinction ratio (ER), channel spacing and highest optical power. The laser experiment for linear SOA concluded with the flattest spectrum in time stability which was true to the characterization modelling result and it also acted differently as nonlinear SOA and BOA that vary greatly to nonlinearity with different PA

Studies on strain and temperature characteristics of a slanted multimode fiber Bragg grating and its application in multiwavelength fiber Raman ring laser

Author name used in this publication: M. S. Demokan2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Hybrid silicon-fiber funable multi-wavelength laser with switchable frequency spacing

Agile optical systems and elastic optical networks demand for flexible, high-performance laser sources. We demonstrate a hybrid silicon-fiber laser that can be largely tuned in wavelength, switched in frequency spacing and easily switched between multi- and single-wavelength operations. Single-mode laser with a fiber-coupled output power of 6 to 8 dBm was measured across the spectral range of 1545 nm to 1560 nm. No significant sign of power limitation from nonlinear absorption or free carrier generation in silicon was found. It is thus expected that a higher output can be obtained by improving the gain saturation performances as well as the fiber-to-chip coupling efficiency. For multi-wavelength operation, we have achieved a frequency spacing switchable between 56 GHz, 75 GHz, and 225 GHz. For both the multi- and single-wavelength operations, a linewidth of less than 20 kHz was measured. All the tuning mechanisms have been realized on the silicon chip, providing a scalable solution for tunable fiber lasers with minimized cost and integration complexity

Advances in Optical Amplifiers

Optical amplifiers play a central role in all categories of fibre communications systems and networks. By compensating for the losses exerted by the transmission medium and the components through which the signals pass, they reduce the need for expensive and slow optical-electrical-optical conversion. The photonic gain media, which are normally based on glass- or semiconductor-based waveguides, can amplify many high speed wavelength division multiplexed channels simultaneously. Recent research has also concentrated on wavelength conversion, switching, demultiplexing in the time domain and other enhanced functions. Advances in Optical Amplifiers presents up to date results on amplifier performance, along with explanations of their relevance, from leading researchers in the field. Its chapters cover amplifiers based on rare earth doped fibres and waveguides, stimulated Raman scattering, nonlinear parametric processes and semiconductor media. Wavelength conversion and other enhanced signal processing functions are also considered in depth. This book is targeted at research, development and design engineers from teams in manufacturing industry, academia and telecommunications service operators

Fiber Sensor Systems Based on Fiber Laser and Microwave Photonic Technologies

Fiber-optic sensors, especially fiber Bragg grating (FBG) sensors are very attractive due to their numerous advantages over traditional sensors, such as light weight, high sensitivity, cost-effectiveness, immunity to electromagnetic interference, ease of multiplexing and so on. Therefore, fiber-optic sensors have been intensively studied during the last several decades. Nowadays, with the development of novel fiber technology, more and more newly invented fiber technologies bring better and superior performance to fiber-optic sensing networks. In this paper, the applications of some advanced photonic technologies including fiber lasers and microwave photonic technologies for fiber sensing applications are reviewed. FBG interrogations based on several kinds of fiber lasers, especially the novel Fourier domain mode locking fiber laser, have been introduced; for the application of microwave photonic technology, examples of microwave photonic filtering utilized as a FBG sensing interrogator and microwave signal generation acting as a transversal loading sensor have been given. Both theoretical analysis and experimental demonstrations have been carried out. The comparison of these advanced photonic technologies for the applications of fiber sensing is carried out and important issues related to the applications have been addressed and the suitable and potential application examples have also been discussed in this paper.Fundamental Research Funds for the Central Universities [2010121059]; Natural Science Foundation of China [61007029]; Projects of Zhejiang Province [2011C21038, 2010R50007]; Program for Science and Technology Innovative Research Team in Zhejiang Normal Universit