Jack Yu

Publications

Darwin K. Serkland, Alejandro J. Grine, Ping-Show Wong, et al. Jack Yu. "Noise characterization of VCSELs for atomic clocks and magnetometers", Proc. SPIE PC13911, Vertical-Cavity Surface-Emitting Lasers XXX, PC1391109 (5 Mar 2026); https://doi.org/10.1117/12.3082136 Conference Paper

(More to come!)

Projects

Peltier-Cooled Sample Stage for LUIS

Designed a thermoelectric (Peltier) temperature-controlled sample stage for Laser-driven Ultrafast Impedance Spectroscopy (LUIS), to enable temperature-dependent studies of phonon-mediated ion transport in solid-state electrolytes. The broader goal is to eventually freeze out phonon modes, though by the Bose-Einstein distribution, Peltier cooling alone only freezes out a limited range of modes. This stage instead serves as a proof of concept for general temperature control in LUIS. The design is also modular, allowing it to support the SMIM technique used elsewhere in the Cushing Lab.

Littman–Metcalf External Cavity Diode Laser (ECDL)

Designed, constructed, and characterized a Littman–Metcalf external cavity diode laser for AR coating evaluation as part of DARPA H6 research at Sandia National Laboratories.

PyCamGUI

A Python GUI for the Raspberry Pi camera built with PyQt5 and picamera2, with live preview, still capture, video recording, focus controls, cropping, preview rotation, and theme toggling.

View on GitHub →

Research Experience

  • Summer 2026 — William N. Lacey SURF Research Fellow, Cushing Lab
    • Modeled lattice anharmonicity in Na₃PS₄ using density functional theory (DFT) to investigate ion transport mechanisms.
    • Designed and integrated a thermoelectric temperature-controlled stage for Laser-driven Ultrafast Impedance Spectroscopy (LUIS) to enable temperature-dependent studies of phonon-mediated ion transport.
  • Jan 2026 – Present — Student Researcher, Experimental Gravity Group (EGG)
    • Designed and simulated experimentally viable non-Gaussian photonic quantum states using Strawberry Fields (TensorFlow backend) and QuTiP.
    • Formulated and optimized high-dimensional optical circuit parameters for multi-mode beam splitter and squeezer networks under realistic photon-loss and noise models.
    • Accelerated large-scale optimization by leveraging Caltech’s HPC cluster to parallelize computationally intensive parameter searches and fidelity evaluations.
  • Jun 2024 – Sep 2025 — Optoelectronics Intern, Sandia National Laboratories
    • Conducted DARPA H6 research developing and characterizing a piezo-tunable etalon for chip-scale atomic clocks through frequency stability and noise analysis.
    • Characterized VCSELs using probe-station measurements and device modeling to optimize laser performance.
    • Designed, constructed, and characterized a Littman–Metcalf external cavity diode laser (ECDL) for AR coating evaluation.