I investigate a new alignment sensing scheme for optical cavities named Radio Frequency Jitter Alignment Sensing Scheme (RFJAS). This scheme is proposed to work along with the currently used WaveFront Sensing Scheme. RFJAS relies on using an electro-optic beam deflector to generate first higher order modes (HOM) sidebands. These sidebands case be used to beat with first HOM from misalignment. Demodulating this beat signal recovers full alignment of the optical cavity, when operating the correct modulation frequency.
Read full paper (PDF) See the animationA key challenge in optical instrumentation is consistent calibration over time. This project involved building a robotic platform that can measure, analyze, and calibrate optical benches using feedback loops. The setupd is mostly controlled using LabVIEW and USB connections.
COMSOL is powerful to model optical compoentns. I used it to model the change in index of refraction inside lithium tantalate (LiTaO3) due to an applied radio frequency voltage across the crystal. This results in beam deflection. The modeled angle of deflection agreed pretty well with the measured angle.
I played around with Zemax to simulate Gaussian beam propagation through different lens setups. It wasn’t part of any research project, but more of a side exploration to understand beam shaping and how design choices like curvature and spacing affect focus and waist. It was super helpful in building intuition for tweaking optical systems in the lab.