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 103 and a quality factor of 1 × 105, 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

Femtosecond laser writing of PPV‐doped three‐dimensional polymeric microstructures

“…By scanning the laser three dimensionally with the help of a galvanometric‐mirror system along with the motorized stage that supports the photoresist, the microstructures are fabricated. Further details regarding the microfabrication process are provided elsewhere . After the fabrication step had been finished, the microstructures were heated in a vacuum oven at 230 °C/6 h to induce the thermal conversion of PTHT to PPV.…”

“…Fs‐laser direct writing via two‐photon polymerization (2PP) has become one of the most promising approaches for high‐precision 3D microfabrication of organic materials . This technique takes advantage of the spatial selectivity provided by two‐photon absorption to fabricate microstructures with high definition and without geometrical limitation.…”

Solid-state random microlasers fabricated via femtosecond laser writing

“…3D microfabrication was performed by controlling both a galvanometric-mirror system and the stage that supports the sample with a computer-aided software. A detailed description of the microfabrication process can be found elsewhere 33 . The microstructures shown herein were fabricated layer by layer until they reach the cover slip, thus their height is limited by the spacer placed between the glass substrate and the cover slip.…”

Energy Transfer‐Assisted Whispering Gallery Mode Lasing in Conjugated Polymer/Europium Hybrid Microsphere Resonators

“…[12] Furthermore, if self-assembly of lanthanide metal-coordinated conjugated polymers form microstructures such as spheres,d isks, rings,e tc, the microstructures would act as whispering gallery mode (WGM) resonators. [13,14] In WGM resonators, luminescence is confinedi nside the microstructures via total internal reflection at the medium/ atmosphere interface. The microcavities functiona so ptical resonators, which can be utilized as micrometer-scale laser sources, [15][16][17][18][19] tools for chemicala nd bio-sensing [20,21] ,o ptical fibers, [22] optical waveguide resonators [23] and other photonic devices.…”