Sökning: "coherent optical system"
Visar resultat 1 - 5 av 56 avhandlingar innehållade orden coherent optical system.
1. Propagation of some coherent and partially coherent laser beams
Sammanfattning : In this thesis, we investigate the propagation of some coherent and partially coherent laser beams, including a dark hollow beam (DHB), an elliptical Gaussian beam (EGB), a flat-topped beam and a twisted anisotropic Gaussian Schell-model (TAGSM) beam, through a paraxial optical system or a turbulent atmosphere. Several theoretical models are proposed to describe a DHB of circular or non-circular symmetry. LÄS MER
2. Phase Noise Tolerant Modulation Formats and DSP Algorithms for Coherent Optical Systems
Sammanfattning : Coherent detection together with multilevel modulation formats has the potential to significantly increase the capacity of existing optical communication systems at no extra cost in signal bandwidth. However, these modulation formats are more susceptible to the impact of different noise sources and distortions as the distance between its constellation points in the complex plane reduces with the modulation index. LÄS MER
3. Spectral Management in Quasi-Phase-Matched Parametric Devices
Sammanfattning : Nonlinear optical interaction in quasi-phase-matched structures opens up unique possibilities to build compact and efficient parametric devices such as optical parametric oscillators, generators, and amplifiers with tailored spectral properties. The focus of this thesis is on novel parametric interactions with periodically-poled KTiOPO4 (PPKTP) as the parametric gain medium. LÄS MER
4. mm-Wave Data Transmission and Measurement Techniques: A Holistic Approach
Sammanfattning : The ever-increasing demand on data services places unprecedented technical requirements on networks capacity. With wireless systems having significant roles in broadband delivery, innovative approaches to their development are imperative. LÄS MER
5. Frequency Noise in Coherent Optical Systems: Impact and Mitigation Methods
Sammanfattning : The increase in capacity demand along with the advancement in digital signal processing (DSP) have recently revived the interest in coherent optical communications and led to its commercialization. However, design and development of robust DSP algorithms for example for carrier phase recovery (CPR) becomes complex as we opt for high order modulation formats such as 16QAM and beyond. LÄS MER