Friday 31 January 2025
A team of researchers has made a significant breakthrough in the development of fiber Bragg grating (FBG) filters, which are crucial components for hybrid microwave-optical quantum technologies. These filters are designed to separate single photon signals from strong classical pump modes, allowing for more efficient and accurate transmission of information.
The new FBGs exhibit high dynamic range measurements, with a suppression depth of over 100 dB at a detuning of 5 GHz from the filter’s pass band center wavelength of 1536.3 nm. This is a significant improvement over previous designs, which often struggled to achieve such high levels of attenuation.
One of the key challenges in designing these filters is achieving the necessary balance between suppression depth and insertion loss. The new FBGs use a clever combination of refractive index changes and π-phase shifts to create a deep notch in the spectrum while minimizing loss.
The researchers used a superheterodyne measurement technique to test the performance of their filters, which involved mixing the filter output with a local oscillator and then detecting the resulting beat signal. This allowed them to measure the attenuation of the filter at various frequencies with high precision.
In addition to their impressive dynamic range, the new FBGs also demonstrate low insertion loss, with a pre-connector insertion loss of just 1.09 dB. This is an important achievement, as it means that these filters can be easily integrated into existing optical communication systems without introducing significant losses.
The development of high-performance FBG filters like these has significant implications for the field of quantum technology. They could potentially be used to improve the efficiency and accuracy of quantum communication systems, which rely on the transmission of single photons over long distances.
Overall, this breakthrough represents a major step forward in the development of fiber Bragg grating filters for hybrid microwave-optical quantum technologies. With their high dynamic range and low insertion loss, these filters are poised to play a key role in enabling more advanced quantum communication systems in the future.
Cite this article: “Breakthrough in Fiber Bragg Grating Filter Technology Enhances Quantum Communication Efficiency”, The Science Archive, 2025.
Fiber Bragg Grating, Filter, Microwave-Optical, Quantum Technology, Single Photon, Classical Pump Modes, Dynamic Range, Insertion Loss, Refractive Index Changes, Π-Phase Shifts
