Search for dissertations about: "photonics"

Showing result 16 - 20 of 201 swedish dissertations containing the word photonics.

  2. 16. Surface-normal multiple quantum well electroabsorption modulators : for optical signal processing and asymmetric free-space communication

    Author : Stéphane Junique; Lars Thylén; Uzi Efron; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spatial light modulators; quantum wells; optical resonator; Fabry–Pérot cavity; electroabsorption modulator; free–space optical communication; Photonics; Fotonik;

    Abstract : Electroabsorption is the physical phenomenon by which the absorption of light in a medium can be controlled by applying an electric field. The Quantum–Confined Stark Effect, which makes the absorption band–edge in quantum wells very field–dependent, together with the strong absorption peak provided by excitons, are the physical foundations for the success of electroabsorption modulators based on quantum well structures in telecommunication networks. READ MORE

  4. 17. Entanglement in quantum communication : preparation and characterization of photonic qubits

    Author : Daniel Ljunggren; Gunnar Björk; Hugo Zbinden; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photonics; Fotonik;

    Abstract : At the heart of quantum physics lies the principle of superposition, and at the heart of information theory lies the bit. Perhaps the most useful property of quantum systems is that they can be loaded with information bits, so-called qubits, that are indefinitely both 0 and 1 until a measurement is made. READ MORE

  5. 18. Structural Information Content of the Optical Field

    Author : Per Martinsson; Ari Friberg; Karl-Heinz Brenner; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photonics; Fotonik;

    Abstract :  The communication modes are a mathematical technique for the description of structural information in optical fields. These modes are orthogonal, optimally  connected functions characteristic of the optical system. Mathematically they are obtained by the singular value decomposition (SVD) of the operator that represents the field propagation. READ MORE

  6. 19. Quantum State Analysis : Probability theory as logic in Quantum mechanics

    Author : Anders Månsson; Anders Karlsson; Gunnar Björk; Ingemar Bengtsson; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quantum; quantum mechanics; state; state analysis; probability; probability theory; logic; Photonics; Fotonik;

    Abstract : Quantum mechanics is basically a mathematical recipe on how to construct physical models. Historically its origin and main domain of application has been in the microscopic regime, although it strictly seen constitutes a general mathematical framework not limited to this regime. READ MORE

  7. 20. Recognition of printed Sinhala characters by direction fields

    Author : Hemakumar Lalith Premaratne; Högskolan i Halmstad; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; HUMANIORA; HUMANITIES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Printed Sinhala characters; Electronics; Photonics; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : Although substantial research has been carried out on Optical Character Recognition (OCR) where a printed or a handwritten document of script is read as an image and converted to the editable text format, for various languages during the last 30 years, majority of Brahmi descended south Asian scripts are yet to achieve a commercial OCR system.... READ MORE