Broadly tunable photon pair generation in a suspended-core fiber

TL;DR

This paper presents a fiber biphoton source with broad tunability achieved by pressurizing gas in a suspended core fiber, enabling frequency tuning without a tunable pump laser, comparable to crystal-based sources.

Contribution

The introduction of pressurized gas into a suspended core fiber enables broad, continuous tunability of biphoton generation without requiring a tunable pump laser.

Findings

Achieved a continuous frequency shift of 0.30 THz per bar of argon pressure.

Demonstrated tunability up to 25 bar of argon gas.

Provided a practical tuning mechanism comparable to crystal sources.

Abstract

Nowadays fiber biphoton sources are nearly as popular as crystal-based ones. They offer a single spatial mode and easy integrability into optical networks. However, fiber sources lack the broad tunability of crystals, which do not require a tunable pump. Here, we report a broadly tunable biphoton source based on a suspended core fiber. This is achieved by introducing pressurized gas into the fibers hollow channels, changing the step index. The mechanism circumvents the need for a tunable pump laser, making this a broadly tunable fiber biphoton source with a convenient tuning mechanism, comparable to crystals. We report a continuous shift of 0.30THz/bar of the sidebands, using up to 25bar of argon.