Optical calibration systems of the Pacific Ocean Neutrino Experiment

TL;DR

This paper details the design, development, and performance testing of novel optical calibration systems for the Pacific Ocean Neutrino Experiment, including innovative light-pulse drivers and isotropic calibration modules, validated through simulations and experiments.

Contribution

It introduces new gallium nitride-based light-pulse driver circuitry and optimized isotropic calibration modules for neutrino detection calibration.

Findings

Achieved emission intensities up to 10^11 photons

Pulse widths as small as 1.4 ns

Simulated isotropy grade of 1.00 ± 0.01

Abstract

This work presents the design and performance characterization of the optical calibration systems produced for the Pacific Ocean Neutrino Experiment (P-ONE). These include novel light-pulse driver circuitry based on gallium nitride field-effect transistor technology and its application to directional and isotropic, self-monitoring optical calibration instruments. A total of 330 directional light pulsers and two isotropic, 17-inch calibration modules (P-CALs) were produced for the first P-ONE line. We present the designs and performance of both the directional and isotropic calibration devices and perform detailed optical characterizations of both full-production batches. In a wavelength range of $365-520\,$nm, our developed driver circuits achieve emission intensities up to $10^{11}\,$photons and pulse widths as small as $1.4\,$ns, respectively. Light-pulse drivers and self-monitoring electronics in the P-CAL were characterized using the same experimental setup, and the instrument's optical-isotropy design was optimized in combination with a dedicated GEANT4-based simulation framework. The optimized P-CAL achieves a simulated isotropy grade of $1.00 \pm 0.01$ across the entire $4 \pi$ solid angle range. These simulation investigations were explicitly confirmed by dedicated measurements in both air and water using two independent experimental setups, and we report the results. With this, a detailed performance estimate for deployed P-CAL modules in P-ONE was possible.