Search for dissertations about: "coherent optical system"

Showing result 1 - 5 of 56 swedish dissertations containing the words coherent optical system.

  2. 1. Propagation of some coherent and partially coherent laser beams

    Author : Yangjian Cai; Sailing He; Franco Gori; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; : dark hollow beam; elliptical Gaussian beam; flat-topped beam; twisted anisotropic Gaussian Schell-model; partial coherent; propagation; paraxial optical system; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Abstract : 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. READ MORE

  4. 2. Phase Noise Tolerant Modulation Formats and DSP Algorithms for Coherent Optical Systems

    Author : Jaime Rodrigo Navarro; Sergei Popov; Gunnar Jacobsen; Richard Schatz; Xiaodan Pang; Oskars Ozolins; Gabriella Bosco; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical communications; carrier phase recovery; blind phase search; circular quadrature amplitude modulation; CmQAM; coherent optical communications; digital signal processing; carrier phase estimation; equalization enhanced phase noise; EEPN; Telecommunication; Telekommunikation;

    Abstract : 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. READ MORE

  5. 3. Spectral Management in Quasi-Phase-Matched Parametric Devices

    Author : Mikael Tiihonen; Fredrik Laurell; Jean-Jaques Zondy; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; optical parametric devices; nonlinear optics; ultraviolet generation; mid-infrared generation; optical parametric oscillator; optical parametric generator; optical parametric amplifier; Optical physics; Optisk fysik;

    Abstract : 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. READ MORE

  6. 4. mm-Wave Data Transmission and Measurement Techniques: A Holistic Approach

    Author : Dhecha Nopchinda; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; estimation theory; data transmission experiment; spectral efficiency; microwave network analysis; communication system; millimeter wave mm-wave system; mutual coupling effects; spectrally efficient frequency division multiplexing SEFDM ; vector network analyzer; wideband measurement.; coherent optical system; impairment compensation algorithm; identification theory; multiplier based transmitter; digital signal processing; Active load pull; linear measurement technique;

    Abstract : 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. READ MORE

  7. 5. Frequency Noise in Coherent Optical Systems: Impact and Mitigation Methods

    Author : Aditya Kakkar; Richard Schatz; Sergei Popov; Gunnar Jacobsen; Xiaodan Pang; Oskars Ozolins; Magnus Karlsson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Equalization enhanced phase noise; frequency noise; coherent optical communications; carrier phase recovery; carrier phase estimation; circular quadrature amplitude modulation; EEPN; CmQAM; blind phase search; phase noise;

    Abstract : 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. READ MORE