Theses and Dissertations

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Volker Quetschke

Second Advisor

Dr. Teviet Creighton

Third Advisor

Dr. Mario Diaz


Since its first detection in 2015, the Light Interferometer Gravitational-Wave Observatory has been notably recognized for the successful measurement of gravitational waves. The successful detection of gravitational-waves comes from the effort of more than a thousand scientist working in collaboration. To characterize the change in displacement of the ETMs, LIGO uses several methods of calibration. The Photon Calibrator has gained significance to the point of becoming the primary calibration tool for the Advanced LIGO detectors. Relying on photon radiation pressure to calibrate the interferometer, the photon calibrator measures the change in displacement of the ETM in relation to the power modulation of a secondary laser beam incident on the ETM. The PCal main task is to accurately measure power from a laser source. This thesis aims to reproduce the integrating spheres calibration setup done at the LIGO-Hanford Observatory. An enhancement to the process of calibration is presented by modifying the method in which the thermal coefficient is measured. A detailed explanation of the physics of the integrating spheres used in this experiment is given. the thesis will discuss on the results discrepancies due to the use of different equipment, and conclude with the implementation of new equipment and potential upgrades on the composition of future experiments.


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