2018/06/19 by Dorian Oser, Oser, D., Florent Mazeas +19 · 2 citations
Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #FOS: Physical sciences #Optical Network Technologies #Optics (physics.optics) #Photonic and Optical Devices #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.1806.08833
openalex publication_date 2018/06/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Selective on-chip optical filters with high rejection levels are key components for a wide range of advanced photonic circuits. However, maximum achievable rejection in state-of-the-art on-chip devices is seriously limited by phase errors arising from fabrication imperfections. Due to coherent interactions, unwanted phase-shifts result in detrimental destructive interferences that distort the filter response, whatever the chosen strategy (resonators, interferometers, Bragg filters, etc.). Here we propose and experimentally demonstrate a radically different approach to overcome this fundamental limitation, based on coherency-broken Bragg filters. We exploit non-coherent interaction among modal-engineered waveguide Bragg gratings separated by single-mode waveguides to yield effective cascading, even in the presence of fabrication errors. This technologically independent approach allows seamless combination of filter stages with moderate performance, providing a dramatic increase of on-chip rejection. Based on this concept, we experimentally demonstrate on-chip non-coherent cascading of Si Bragg filters with a record light rejection exceeding 80 dB in the C-band.