Efficient, ultra-high attenuation fiber Bragg grating filter for photon noise suppression

TL;DR

This paper presents a novel fiber Bragg grating filter with ultra-high attenuation and steep spectral features, significantly improving photon noise suppression for advanced photonic applications.

Contribution

The work introduces a fiber Bragg grating with multiple π-phase discontinuities achieving ultra-high attenuation and steep spectral features, demonstrating high precision and manufacturability.

Findings

Maximum gradient of 90.6 dB/GHz in the bandpass

128 dB of suppression in the notch filter

Performance closely matches simulations

Abstract

Precision optical filters are key components for current and future photonic technologies. Here, we demonstrate a low loss spectral filter consisting of an ultrasteep bandpass feature with a maximum gradient of (90.6$\pm$0.7) dB/GHz, centred within a notch filter with (128$\pm$6) dB of suppression. The filter consists of a fiber Bragg grating with multiple $\pi$-phase discontinuities inscribed into a single mode photosensitive fiber. The measured performance closely matches the simulated spectrum calculated from the design parameters indicating a high degree of confidence in the repeatability and manufacture of such devices. These filters show great promise for applications reliant on high-frequency resolution noise suppression, such as quantum networking, and highlight the opportunities for the versatility, efficiency, and extreme suppression offered by high-performance fiber Bragg grating devices.