Cryocooled dielectric crystal whispering-gallery mode resonators and their application to ultra-stable frequency generation

Nitin Nand

    Research output: ThesisDoctoral Thesis

    422 Downloads (Pure)

    Abstract

    [Truncated abstract] Very long baseline interferometry is advancing towards higher frequencies to increase angular resolution to enable high quality deep space imaging. But observations become increasingly challenging as the wavelength becomes short. VLBI at millimeter wavelengths (mm-VLBI) suffer from low sensitivity due to instrumental noise and atmospheric effects which reduce phase coherence time. To increase coherence, a local oscillator frequency standard with noise performance much better than the currently used H-maser is required, provided weather conditions are good.

    This thesis presents the development and noise characterization of a cryogenic sapphire oscillator (CSO) based on a cryocooler (cryoCSO) and frequency synthesizer (FS). These two prototypes are capable of delivering ultra-low phase noise and ultra-high frequency stability references suitable for mm-VLBI.

    Original languageEnglish
    QualificationDoctor of Philosophy
    Publication statusUnpublished - 2014

    Fingerprint

    whispering gallery modes
    very long base interferometry
    resonators
    crystals
    oscillators
    frequency synthesizers
    atmospheric effects
    deep space
    phase coherence
    frequency standards
    frequency stability
    theses
    ultrahigh frequencies
    masers
    angular resolution
    weather
    wavelengths
    cryogenics
    interferometry
    sapphire

    Cite this

    @phdthesis{3bd996f762414bd5a5bd13943a001a26,
    title = "Cryocooled dielectric crystal whispering-gallery mode resonators and their application to ultra-stable frequency generation",
    abstract = "[Truncated abstract] Very long baseline interferometry is advancing towards higher frequencies to increase angular resolution to enable high quality deep space imaging. But observations become increasingly challenging as the wavelength becomes short. VLBI at millimeter wavelengths (mm-VLBI) suffer from low sensitivity due to instrumental noise and atmospheric effects which reduce phase coherence time. To increase coherence, a local oscillator frequency standard with noise performance much better than the currently used H-maser is required, provided weather conditions are good. This thesis presents the development and noise characterization of a cryogenic sapphire oscillator (CSO) based on a cryocooler (cryoCSO) and frequency synthesizer (FS). These two prototypes are capable of delivering ultra-low phase noise and ultra-high frequency stability references suitable for mm-VLBI.",
    keywords = "Frequency metrology, Phase noise, Frequency stability, Cryogenic sapphire oscillators, Pulse-tube crypcooler, Frequency synthesizer, Allan deviation, mm-VLBI",
    author = "Nitin Nand",
    year = "2014",
    language = "English",

    }

    TY - THES

    T1 - Cryocooled dielectric crystal whispering-gallery mode resonators and their application to ultra-stable frequency generation

    AU - Nand, Nitin

    PY - 2014

    Y1 - 2014

    N2 - [Truncated abstract] Very long baseline interferometry is advancing towards higher frequencies to increase angular resolution to enable high quality deep space imaging. But observations become increasingly challenging as the wavelength becomes short. VLBI at millimeter wavelengths (mm-VLBI) suffer from low sensitivity due to instrumental noise and atmospheric effects which reduce phase coherence time. To increase coherence, a local oscillator frequency standard with noise performance much better than the currently used H-maser is required, provided weather conditions are good. This thesis presents the development and noise characterization of a cryogenic sapphire oscillator (CSO) based on a cryocooler (cryoCSO) and frequency synthesizer (FS). These two prototypes are capable of delivering ultra-low phase noise and ultra-high frequency stability references suitable for mm-VLBI.

    AB - [Truncated abstract] Very long baseline interferometry is advancing towards higher frequencies to increase angular resolution to enable high quality deep space imaging. But observations become increasingly challenging as the wavelength becomes short. VLBI at millimeter wavelengths (mm-VLBI) suffer from low sensitivity due to instrumental noise and atmospheric effects which reduce phase coherence time. To increase coherence, a local oscillator frequency standard with noise performance much better than the currently used H-maser is required, provided weather conditions are good. This thesis presents the development and noise characterization of a cryogenic sapphire oscillator (CSO) based on a cryocooler (cryoCSO) and frequency synthesizer (FS). These two prototypes are capable of delivering ultra-low phase noise and ultra-high frequency stability references suitable for mm-VLBI.

    KW - Frequency metrology

    KW - Phase noise

    KW - Frequency stability

    KW - Cryogenic sapphire oscillators

    KW - Pulse-tube crypcooler

    KW - Frequency synthesizer

    KW - Allan deviation

    KW - mm-VLBI

    M3 - Doctoral Thesis

    ER -