Wavelength-Selective Coupling to Vertical Higher Order Modes in a 500-nm-Thick Silicon Multimode Waveguide Using Long- and Short-Period Gratings

• الحاوية / القاعدة: IEEE Access
• المؤلفون الرئيسيون: Hyeongjung Kim, Jungwoo Lee, Jihoon Seo, Minjin Kim, Min-Suk Kwon
• التنسيق: مقال
• اللغة: الإنجليزية
• منشور في: IEEE 2025-01-01
• الموضوعات: Integrated optics; silicon photonics; multimode waveguides; Bragg gratings; notch filters
• الوصول للمادة أونلاين: https://ieeexplore.ieee.org/document/11151805/
• تدمد: 2169-3536

This work explores thick silicon multimode waveguides (MMWs), focusing on vertical multimode operation. We present grating-assisted coupling structures to efficiently convert the fundamental mode to vertical higher-order modes in a 500-nm-thick silicon MMW. Both forward and backward coupling schemes are investigated. The forward coupling with a long-period grating exhibits broadband conversion over a coupling length less than <inline-formula> <tex-math notation="LaTeX">$40\mu $ </tex-math></inline-formula>m. The backward coupling with a short-period grating demonstrates mode conversion with a 3-dB bandwidth ranging from 5.8 to 13.3 nm. These results open new avenues for applications such as on-chip spatial mode multiplexing with a higher capacity.