Low-loss Waveguide Bend Supporting a Whispering Gallery Mode

A low-loss waveguide bend is experimentally demonstrated to reduce the loss in a circular bend from 0.372 ± 0.032 dB to 0.016 ± 0.003 dB. Moreover, A ring resonator based on this design is demonstrated with an FSR of 21.51 ± 0.01 nm in the O-band while keeping a low ring internal loss of 0.038 ± 0.003 dB.