Electrically tuned whispering gallery mode microresonator based on Kagome photonic crystal fibers infiltrated with nematic liquid crystals

In this study, an electrically tunable whispering gallery mode (WGM) microresonator based on Kagome hollow-core photonic crystal fiber (HC-PCF) is proposed by infiltrating the cross-sectional air holes with nematic liquid crystals (NLCs). Experimental results indicate that the LC molecules turn out in planar alignment. As the applied electric field strength gradually increases, the WGM resonance wavelengths shift toward the longer-wavelength region. The Freedericksz transition threshold of the proposed Kagome HC-PCF microresonator is experimentally proved to be around 1.2 V mu m(-1). The electrically tunable microresonator, integrated with NLCs, is anticipated to find potential applications in optical filtering, all-optical switching, and electrically controlled micro-optics devices. (C) 2019 Optical Society of America