Development of an image converter of radical design

A long term investigation of thin film sensors, monolithic photo-field effect transistors, and epitaxially diffused phototransistors and photodiodes to meet requirements to produce acceptable all solid state, electronically scanned imaging system, led to the production of an advanced engineering model camera which employs a 200,000 element phototransistor array (organized in a matrix of 400 rows by 500 columns) to secure resolution comparable to commercial television. The full investigation is described for the period July 1962 through July 1972, and covers the following broad topics in detail: (1) sensor monoliths; (2) fabrication technology; (3) functional theory; (4) system methodology; and (5) deployment profile. A summary of the work and conclusions are given, along with extensive schematic diagrams of the final solid state imaging system product

A Solid-State Phase Camera for Advanced Gravitational Wave Detectors

I present a novel way of wavefront sensing using a commercially available, continuouswavetime-of- ight camera with QVGA-resolution. This CMOS phase camera is capable of sensing externally modulated light sources with frequencies up to 100 MHz. The high-spatial-resolution of the sensor, combined with our integrated control electronics, allows the camera to image power modulation index as low as -62 dBc/second/pixel. The phase camera is applicable to problems where alignment and mode-mismatch sensing is needed and suited for diagnostic and control applications in gravitationalwave detectors. Specically, I explore the use of the phase camera in sensing the beat signals due to thermal distortions from point-like heat absorbers on the test masses in the Advanced LIGO detectors. The camera is capable of sensing optical path distortions greater than about two nanometers in the Advanced LIGO input mirrors, limited by the phase resolution. In homodyne readout, the performance can reach up to 0.1 nm, limited by the modulation amplitude sensitivity

Advanced Virgo: A second-generation interferometric gravitational wave detector

Advanced Virgo is the project to upgrade the Virgo interferometric detector of gravitational waves, with the aim of increasing the number of observable galaxies (and thus the detection rate) by three orders of magnitude. The project is now in an advanced construction phase and the assembly and integration will be completed by the end of 2015. Advanced Virgo will be part of a network, alongside the two Advanced LIGO detectors in the US and GEO HF in Germany, with the goal of contributing to the early detections of gravitational waves and to the opening a new window of observation on the universe. In this paper we describe the main features of the Advanced Virgo detector and outline the status of the construction

Making it work : second generation interferometry in GEO 600!

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Classical and non-classical laser sources for current and future gravitational wave detectors

Current and future gravitational wave detectors (GWDs) place high demands on their subsystems to reach their sensitivity target. Therefore, the stabilized laser systems and squeezed light sources have to fulfill the highest requirements to allow for the anticipated sensitivity. Currently, second-generation GWDs use lasers at a wavelength of 1064 nm to measure differential arm length changes in their Michelson interferometers and since 2015 they are detecting gravitational waves. In this thesis, Nd:YVO4 solid-state laser amplifiers with output powers of up to 114 W and a very high spatial purity down to 2.9% higher order mode content were set up, tested, and integrated into a GWD laser stabilization environment. The amplifiers allowed for low noise and highly reliable operation, such that they were integrated into the laser systems of currently operating GWDs. Future ground-based third-generation GWDs, like the Einstein Telescope or Cosmic Explorer, are supposed to increase their sensitivity by more than one order of magnitude compared to the current generation. One foreseen improvement is to lower the mirrors' thermal noise by installing cryogenically-cooled silicon mirrors in some of their interferometers. Due to the required transparency of silicon, a change of the laser wavelength to either 1550 nm or 2 µm is necessary. A detailed characterization of laser sources and amplifiers at 1550 nm is presented in this thesis to select a suitable configuration for a GWD laser system at this wavelength. High-bandwidth frequency and power stabilization schemes were designed for the selected laser system, which were tailored for the needs of GWDs. These laser stabilizations were operated simultaneously and characterized by out-of-loop sensors. Independent measurements proved a shot noise limited operation of the power stabilization, below a relative power noise of 10^{-8} Hz^{-1/2} between 100 Hz to 100 kHz, and a frequency noise down to 400 mHzHz^{-1/2}, achieved with an active frequency stabilization with a unity-gain frequency above 2 MHz. The generation of strongly squeezed vacuum states of light is a key technology for current and future ground-based GWDs to reach sensitivities beyond their classical quantum noise limit. By employing the stabilized laser system in a newly designed squeezed light source, the direct measurement of up to 11.5 dB squeezing at 1550 nm wavelength over the entire detection bandwidth of future ground-based GWDs ranging from 10 kHz down to below 1 Hz was demonstrated, for the first time in literature. Furthermore, the direct observation of a quantum shot-noise reduction of up to 13.5 +/- 0.1 dB at MHz frequencies allowed to derive a precise constraint on the absolute quantum efficiency of the photodiodes used for balanced homodyne detection. All these results provide important knowledge regarding laser systems and squeezed light sources for future GWDs, as well as for the whole field of high precision metrology or cryptography, where ultra-low noise laser systems and non-classical states of light are of great interest

JUNO Conceptual Design Report

The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine the neutrino mass hierarchy using an underground liquid scintillator detector. It is located 53 km away from both Yangjiang and Taishan Nuclear Power Plants in Guangdong, China. The experimental hall, spanning more than 50 meters, is under a granite mountain of over 700 m overburden. Within six years of running, the detection of reactor antineutrinos can resolve the neutrino mass hierarchy at a confidence level of 3-4$\sigma$, and determine neutrino oscillation parameters $\sin^2\theta_{12}$, $\Delta m^2_{21}$, and $|\Delta m^2_{ee}|$ to an accuracy of better than 1%. The JUNO detector can be also used to study terrestrial and extra-terrestrial neutrinos and new physics beyond the Standard Model. The central detector contains 20,000 tons liquid scintillator with an acrylic sphere of 35 m in diameter. $\sim$17,000 508-mm diameter PMTs with high quantum efficiency provide $\sim$75% optical coverage. The current choice of the liquid scintillator is: linear alkyl benzene (LAB) as the solvent, plus PPO as the scintillation fluor and a wavelength-shifter (Bis-MSB). The number of detected photoelectrons per MeV is larger than 1,100 and the energy resolution is expected to be 3% at 1 MeV. The calibration system is designed to deploy multiple sources to cover the entire energy range of reactor antineutrinos, and to achieve a full-volume position coverage inside the detector. The veto system is used for muon detection, muon induced background study and reduction. It consists of a Water Cherenkov detector and a Top Tracker system. The readout system, the detector control system and the offline system insure efficient and stable data acquisition and processing.Comment: 328 pages, 211 figure

Adaptive Mode Matching in Advanced LIGO and Beyond

The era of gravitational wave astronomy was ushered in by the LIGO (Laser Interferometer Gravitational-Wave Observatory) collaboration with the detection of a binary black hole collision [2]. The event that shook the foundation of space-time allowed mankind to view the cosmos in a way that had never been done previously. Since then, another remarkable event was found by the LIGO and Virgo detectors where two neutron stars collided, sending both gravitational and electromagnetic waves to earth [3]. LIGO was built with the purpose of detecting the ripples in space-time caused by astrophysical events with the hopes of understanding the complexities hidden within the cosmos. In 2011, the primary stages of Advanced LIGO were installed and commissioned to start the first observing run (O1). During the writing of this thesis, the detectors had hardware replaced in order to mitigate noise from scattered light and new optics which reduced the losses from absorption. The upgrades were in preparation for the third observing run (O3) and the work presented here is primarily focused on experimental techniques for operating at higher power and mode matching Gaussian beams in the dual-recycled Michelson interferometer for the Advanced LIGO era and beyond. The first two chapters discuss the fundamentals of gravitational waves and the LIGO detector configurations. The third chapter introduces the reader to fundamentals in mode matching Gaussian laser beams. The fourth and fifth chapter summarizes the author\u27s work at Syracuse University. The sixth chapter deals with work at the LIGO Hanford observatory with an emphasis on mode sensing and high-power operation