A Fiber Optic System for Automatic System Identification of the Frequency Response of the Photodetectors in an Interferometric Gravitational Wave Detector

Document #:

LIGO-P1400214-v2

Document type:

P - Publications

Abstract:

Before you can build an Interferometric Gravitational Wave Detector that works at the limits set by Quantum Mechanics it is necessary to first build a Detector that you can control and read out optically. There are several photodiodes in such a detector used to sense various degrees of freedom of the system to provide feedback signals for the control of the detector. In addition there is the main interferometric Gravitational Wave Signal that is read out with a photodiode. In this precision physics experiment it is necessary to treat the photodiode and its readout electronics as systems whose performance including the frequency response can change over time and with changing operating conditions. In this project we will build an automatic frequency response measurement system for the gravitational wave detector photodiodes. This system will use a modulated diode laser coupled through a fiber optic distribution system to illuminate the photodiodes and then the computer control system will measure the frequency response of the photo-receivers sequentially using a network analyzer. This experiment will involve hands-on work with lasers, precision mechanical systems, optical equipment, fiber optic components, digital controls and a network analyzer. Skills in python, Matlab, electronics, and laser optics would be helpful.

Files in Document:

• Nichin_SURF report P1400214-v2.pdf (456.2 kB)

Topics:

• Basic R&D

Authors:

• Nichin Sreekantaswamy
• Eric Gustafson
• Jameson Graef Rollins

Keywords:

SURF2014 Fiber Optic System Automatic System Identification Frequency Response Photodetectors Interferometric Gravitational Wave Detector

Referenced by:

• LIGO-P1400235: LIGO SURF 2014 Final Reports