Femtosecond laser fabrication of high‐Q whispering gallery mode microresonators via two‐photon polymerization

ABSTRACT Whispering gallery mode microresonators have been triggering considerable advances in science due to their ability to confine light within small dielectric volumes, which makes them suitable for a wide range of applications. Lithographic approaches have been the dominant technique for fabricating microresonators; however, they restrict the choice of materials due to their multistep processing nature. As an alternative, they report the direct laser fabrication of acrylic based hollow microcylinder resonators, via two‐photon polymerization, with good structural integrity and sidewall roughness of 1.5 nm, which make them promising candidates for photonic applications in the near‐infrared. Such polymeric microresonators exhibit finesse close to 10 3 and a quality factor of 1 10 5 , a performance achieved without any additional processing step, which would restrict the choices of materials to be incorporated into the polymeric resonator. This advantage thereby broadens the widespread use of the polymeric microresonators, making them an excellent platform for lasing and nonlinear optics studies in the near‐infrared. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 569–574