Controlling of spatial modes in multi-mode photonic crystal nanobeam cavity

We numerically and experimentally present the characteristics of disturbed spatial modes (air mode and dielectric mode) in multi-mode photonic crystal nanobeam cavity (PCNC) in the mid-infrared wavelength range. The results show that the resonance wavelength of the spatial modes can be controlled by modifying the size, period and position of the central periodical mirrors in PCNC, achieving better utilization of the spectrum resource. Additionally, side coupling characteristics of PCNC supporting both air and dielectric modes are investigated for the first time. This work serves as a proof of design method that the spatial modes can be controlled flexibly in PCNC, paving the way to achieve integrated multi-function devices in a limited spectrum range. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

We present the characteristics of disturbed spatial modes in a multi-mode photonic crystal nanobeam cavity (PCNC) in the mid-infrared wavelength range through numerical and experimental methods. The resonance wavelength of the spatial modes can be controlled by modifying the size, period, and position of the central periodical mirrors in PCNC, leading to better utilization of the spectrum resource. Moreover, we investigate the side coupling characteristics of PCNC supporting both air and dielectric modes for the first time. This work serves as a proof of design method for flexible control of spatial modes in PCNC, enabling the realization of integrated multi-function devices in a limited spectrum range.