Nanowerk  June 17, 2022 Conventionally, high-Q resonators that have a minimum loss in optical power are used to generate ultra-narrow optical features in solid-state, but they require complex and costly fabrication processes, which limits their large-scale commercial production. Researchers in Canada have demonstrated a resonator-free approach to generate such ultra-narrow features exploiting gain-enhanced polarization pulling in a twisted birefringent medium where polarization eigenmodes are frequency-dependent. Using Brillouin gain in a commercial spun fibre, they experimentally achieved a 0.72 MHz spectral dip. Further optimization can potentially reduce the linewidth to <0.1 MHz. According to the researchers their approach is simple and broadly […]