Search for dissertations about: "Phase locking"

Showing result 1 - 5 of 35 swedish dissertations containing the words Phase locking.

  2. 1. Optical Transmission Systems Based on Phase-Sensitive Amplifiers

    Author : Samuel L I Olsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical injection locking; fiber nonlinearities; optical fiber communication; fiber nonlinearity mitigation; four-wave mixing; fiber optic parametric amplification; low-noise amplification; phase-sensitive amplification; fibre optics;

    Abstract : The capacity and reach of today's long-haul fiber optical communication systems is limited by amplifier noise and fiber nonlinearities. Conventional, phase-insensitiveamplifiers (PIAs), have a quantum limited noise figure (NF) of 3 dB at high gain, meaning that with a shot-noise limited input signal the signal-to-noise ratio (SNR)is degraded by at least 3 dB. READ MORE

  4. 2. Phase Sensitive Amplifiers for Free-Space Optical Communications

    Author : Ravikiran Kakarla; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase sensitive amplifier; sensitivity; optical injection locking; noisefigure;

    Abstract : The demand for high data rate free-space communications is increasing due to the planned future space exploration missions. In the next few years there is a need to increase the speed by 100 times according to NASA, and this necessitates that transmission systems operate at higher carrier frequencies. READ MORE

  5. 3. Low noise frequency combs and injection locking for broadly tunable laser sources and tomography

    Author : Connor Skehan; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; relative intensity noise; frequency comb; frequency noise; phase noise; optical injection locking;

    Abstract : Lasers have revolutionized the world of physics by providing a highly coherent source of photons which may be used for a large variety of purposes. Here, we study the noise properties of frequency combs - a special class of frequency stabilized and mutually coherent multi-mode lasers, as well as the optical injection locking of comb tones as a means for low noise amplification and tone selection. READ MORE

  6. 4. Towards Practical Implementation of Phase-Sensitive Amplifier Based Transmission Systems

    Author : Samuel L I Olsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phase-sensitive amplification; four-wave mixing; nonlinear optical signal processing; optical injection locking; fiber nonlinearities; fiber optic parametric amplification;

    Abstract : All commercially available optical amplifiers are so-called phase-insensitive amplifiers (PIAs) which degrade the signal-to-noise ratio (SNR) through the amplification process. This kind of amplifier has a quantum limited noise figure (NF) of 3 dB. READ MORE

  7. 5. Design and characterisation of terahertz Schottky diode harmonic mixers

    Author : Divya Jayasankar; RISE Research Institutes of Sweden; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Schottky diodes; Phase locking; Harmonic mixers; Heterodyne receivers; Terahertz electronics; Frequency stabilisation; Frequency converters;

    Abstract : Efficient, compact, and reliable terahertz frequency converters preferably operating at ambient temperature are crucial for stabilising far-infrared optical sources. This thesis focuses on the design and characterisation of terahertz Schottky diode harmonic mixers for frequency stabilisation of quantum-cascade lasers. READ MORE