title: Integrative optofluidic microcavity with tubular channels and coupled waveguides via two-photon polymerization.
abstract: Miniaturization of functional devices and systems demands new design and fabrication approaches for lab-on-a-chip application and optical integrative systems. By using a direct laser writing (DLW) technique based on two-photon polymerization (TPP), a highly integrative optofluidic refractometer is fabricated and demonstrated based on tubular optical microcavities coupled with waveguides. Such tubular devices can support high quality factor (Q-factor) up to 3600 via fiber taper coupling. Microtubes with various diameters and wall thicknesses are constructed with optimized writing direction and conditions. Under a liquid-in-tube sensing configuration, a maximal sensitivity of 390 nm per refractive index unit (RIU) is achieved with subwavelength wall thickness (0.5 μm), which offers a detection limit of the devices in the order of 10-5RIU. Such tubular microcavities with coupled waveguides underneath present excellent optofluidic sensing performance, which proves that TPP technology can integrate more functions or devices on a chip in one-step formation.
authors.affiliation: Department of Materials Science & State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 200433, China. yfm@fudan.edu.cn and Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215125, China.
authors.forename: Yonglei
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Materials Science & State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 200433, China. yfm@fudan.edu.cn.
authors.forename: Yangfu
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Department of Materials Science & State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 200433, China. yfm@fudan.edu.cn and School of Information Science & Technology, Fudan University, Shanghai 200433, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Materials Science & State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 200433, China. yfm@fudan.edu.cn.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Materials Science & State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 200433, China. yfm@fudan.edu.cn.
authors.forename: Shiwei
authors.initials: S
authors.lastname: Tang
authors.affiliation: Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215125, China.
authors.forename: Chunping
authors.initials: C
authors.lastname: Jiang
authors.affiliation: School of Information Science & Technology, Fudan University, Shanghai 200433, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Department of Materials Science & State Key Laboratory of ASIC and Systems, Fudan University, Shanghai 200433, China. yfm@fudan.edu.cn.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Mei