Hybrid silica-azopolymer optical microfiber coupler for high-performance in-line all-optical switching

All-optical switches (AOSs) with the unique functionality of light controlling by light are the essential components of advanced photonics. However, it is still a grand challenge to propose materials with appropriate nonlinear effects and structures with high-performance all-optical switching. This study proposes an AOS with a hybrid silica-azopolymer optical microfiber coupler configuration. This structure is characterized by in-line switching functionality, extremely high extinction ratio of 22 dB at λ = 1550 nm, low-insertion loss (<1 dB), and ease of fabrication process. It is shown that, because of the photo-induced birefringence in the azopolymer microfiber, the functionality of the introduced switch depends on the polarizations of the controlling and propagating light signals. Moreover, using full-wave electromagnetic simulations, the performance of the hybrid AOS is explained and clarified.