Extreme environmental testing of a rugged correlated photon source

TL;DR

This paper reports on the development and testing of rugged single photon sources for quantum key distribution, demonstrating their resilience to environmental stresses but highlighting limitations under extreme conditions.

Contribution

It introduces a ruggedized photon source based on spontaneous parametric downconversion and evaluates its reliability under various environmental stresses.

Findings

Device tolerates launch and orbital conditions

Resilient to casual mishandling by students

Fails under forcible disassembly conditions

Abstract

Experiments in long distance quantum key distribution have motivated the development of ruggedised single photon sources, capable of producing useful correlations even when removed from the warm, nurturing environment found in most optics laboratories. As part of an ongoing pro- gramme to place such devices into low earth orbit (LEO), we have developed and built a number of rugged single photon sources based on spontaneous parametric downconversion. In order to evalu- ate device reliability, we have subjected our design to various thermal, mechanical and atmospheric stresses. Our results show that while such a device may tolerate launch into orbit, operation in orbit and casual mishandling by graduate students, it is probably unable to survive the forcible disassembly of a launch vehicle at the top of a ball of rapidly expanding and oxidising kerosene and liquid oxygen.