Research of rare-earth-doped double-clad fiber（DCF） lasers is one of the subjects on the frontiers of optoelectronic technology.By using DCF and cladding-pumped technology,the conversion efficiency and output power of fiber lasers can be greatly improved,and a variety of nonlinear effects can be effectively inhibited as well.Therefore,it has become an important way to develop high power lasers.Since
(Read More…)
With the rapid development of the global communications, the ultrahigh capacity of a new generation of optical fiber communication system is demanded urgently. Therefore, optical amplifiers are encountering a great challenge as one of the vital components of optical communication system. Currently, as a new generation of amplifier, Raman fiber amplifier has been thought as
(Read More…)
Wavelength-tunable Yb3+-doped double-clad fiber（YDCF） lasers have great potential applications in many fields.In this thesis,theoretical and experimental investigations on wavelength-tunable YDCF lasers are reported.The research and development of the rare-earth doped fiber lasers and tunable fiber lasers are reviewed.The structures and principles of tunable YDCF lasers are introduced,including the structures and properties of YDCF,the pump and
(Read More…)
It attracted quite some attention to design the reduced-order filters to reduce the numerical complexity and computational burden of the real-time filtering process over the past decade.In this dissertation,the reduced-order filter design methods are investigated.The main contributions of this dissertation are as follows.Firstly,we consider reduced-order H∞filtering design for continuous singular systems.By adding a complementary constraint,the
(Read More…)
LDPC code is the most superb sort of error control codes,especially when it has long code length and adopts soft decoding method. This code can get very low BER in extremely noisy circumstances, so it is the perfect candidate for wireless and space telecommunications. In DMB-T FEC has applied BCH+LDPC cascade form and LDPC code
(Read More…)
Organic light-emitting device（OLED） is a new kind of plane display technology based on organic electroluminescent material.Because of the excellent display characteristics of OLED,it has been expected to be one of the most ideal and potential display technologies in the near future.OLED can also be widely applied in the field of solid-state illumination as a light-source
(Read More…)
Solder joints are the most fragile parts in electronic package. The properties of joints made of lead-free material are harder and crisper than those of lead-contained material. They tend to break due to dynamic loading by absorbing the impact energy and result in malfunction. Thus , how to improve the reliability of contact joints made
(Read More…)
AVS is the audio video coding standard made with fully patent by the Audio Video Coding Standard Workgroup of China in 2003.The development of China’s multimedia industry has been restricted by the patents of H.264,MPEG-2.This problem can now be solved with AVS’s patent pool policy.AVS,which has occupied an important position in many fields in China,such
(Read More…)
With the rapid economic development and continuous improvement of people’s living standard,more and more attention has been paid to security issues.The expansion of market demand and the development of information technology promote the continuous development of video surveillance technologies.Video surveillance applications continue to expand into all aspects of life such as education,government, transportation,entertainment,medical services.Digitalization and
(Read More…)
With the development of modern industrial technology, a large number of non-linear power electronic equipments are applied widely in power system, which causes too much harmonic pollution. At the same time the power quality and the safe operation become worse sharply. Hence, harmonics suppression is imperative under the situation. The both Active Power Filter (APF)
(Read More…)
