Ultra-Broadband Polymer 1 × 2 Thermo-Optic Mode Switch

• Main Authors: Yang Gao, Yan Xu, Songyue Liu, Xiaojian Fan, Xibin Wang, Xiaoqiang Sun, Daming Zhang
• Format: Article
• Language: English
• Published: IEEE 2021-01-01
• Series: IEEE Photonics Journal
• Subjects: Optical interconnects; polymer; waveguide devices; mode switch
• Online Access: https://ieeexplore.ieee.org/document/9484743/

Optical mode switch is a key device for reconfigurable mode-division-multiplexing (MDM) technique. Here, an ultra-broadband 1×2 mode switch based on cascaded Mach-Zehnder interferometer and asymmetric Y-branch is proposed. The input E₀₀ or E₁₀ mode will be converted to E₀₀ mode and switched between two output ports by changing the working state of electrode. When E₀₀ mode is launched, the measured insertion loss of fabricated switch is 3.3 dB (off-state)/3.4 dB (on-state), and corresponding crosstalk is −18.8 dB (off-state)/−16.1 dB (on-state) at 1550 nm, respectively. Due to the adoption of polymer with high thermo-optic coefficient as the waveguide material, the measured switching power is 10.3 mW. The captured far-field output mode patterns prove the wavelength independence of proposed mode switch within the range from 1500 to 1630 nm. This broadband operation mode switch has potentials in wavelength-division-multiplexing & MDM complex systems, as well as cost-effective low-end switching applications.