arXiv subjects

Mitchell Schiworski

Publications and source records attributed to Mitchell Schiworski.

3 recordsLinked to original sources

arXiv2026

Combined Cavity Alignment and Mode-Mismatch Sensing using RF-QPD Sensors

In this article we describe a scheme for sensing both the mode mismatch and alignment of a cavity which does not require custom sensors and uses only Quadrant Photo-Detectors (QPDs). The technique is simple relying upon cylindrical lenses and thoughtful Gouy phase telescope design, and is trivial to implement alongside a Pound-Drever-Hall (PDH) locking scheme. The Gouy phase telescope design utilizes all three of the QPDs to sense each degree of freedom which also increases sensitivity and provides redundancy. The technique we show also works without RF modulation, which is useful for providing other general diagnostic information in complex optical experiments. An analytical overview of the technique as well as generic design equations for the Gouy phase telescope is provided. Finally, a detailed optical simulation is presented to verify the technique.

physics.optics↗

arXiv2024

You only thermoelastically deform once: Point Absorber Detection in LIGO Test Masses with YOLO

Current and future gravitational-wave observatories rely on large-scale, precision interferometers to detect the gravitational-wave signals. However, microscopic imperfections on the test masses, known as point absorbers, cause problematic heating of the optic via absorption of the high-power laser beam, which results in diminished sensitivity, lock loss, or even permanent damage. Consistent monitoring of the test masses is crucial for detecting, characterizing, and ultimately removing point absorbers. We present a machine-learning algorithm for detecting point absorbers based on the object-detection algorithm You Only Look Once (YOLO). The algorithm can perform this task in situ while the detector is in operation. We validate our algorithm by comparing it with past reports of point absorbers identified by humans at LIGO. The algorithm confidently identifies the same point absorbers as humans with minimal false positives. It also identifies some point absorbers previously not identified by humans, which we confirm with human follow-up. We highlight the potential of machine learning in commissioning efforts.

astro-ph.IM↗

arXiv2022

Observing the optical modes of parametric instability

Parametric Instability (PI) is a phenomenon that results from resonant interactions between optical and acoustic modes of a laser cavity. This is problematic in gravitational wave interferometers where the high intra-cavity power and low mechanical loss mirror suspension systems create an environment where three mode PI will occur without intervention. We demonstrate a technique for real time imaging of the amplitude and phase of the optical modes of PI yielding the first ever images of this phenomenon which could form part of active control strategies for future detectors.

physics.optics↗