Study On Functionalized Photonic Micro/Nanodevices Based On Femtosecond Laser Two-photon Absorption

In recent years, owing to the development of Integrated optoelectronic and various planar waveguides, the higher integration and more complexity of micro-nano devices, the optical device structure become more complicated, hence integrated optical chip have got a rapid development, which has been widely used in optical instruments such as classical optics. Among the kinds of fabrication techniques, femtosecond laser direct writing(Fs LDW) has many potential applications due to its advantages, such as limited heat-affected zone and more precision machining. Ultrashort pulse micro processing technology have been studied in detail in many scientific experiments. With the help of FsLDW, various micro nano photonic devices of high quality for two-dimensional and three-dimensional have been successfully prepared. However, most of them are based on traditional artificial materials like synthetic polymers, and the prototyped functions generally rely more on different geometric structures of devices. This largely hinders the multifunctionalzation of Fs LDW-fabricated photonic micro/nano-devices and their development in many areas. To solve problems above, we use Fs LDW to customize functionalized photonic micro/nano-devices in this paper. The main research contents are as follows:I. Whispering gallery mode microdisk lasers based on traditional artificial polymer. We first compound the photoresist(SU-8) with gain material(Rhodamine 6G), then established a picosecond laser pumping system. Using two-photon femtosecond laser micro-processing technology fabricates a series of microsphere(diameter: from 5μm to 25μm), then through the light induced luminescence photoluminescence and lasing spectrum, came up with an interesting solution to realize a monomode laser or a particular wavelength resonance laser.II. Protein-based functional whispering gallery mode microdisk lasers. high-quality protein-based WGM true-3D micro-disks are Fs LDW-fabricated from aqueous ink comprehensively relying on processing-parameter optimization, high-viscosity protein protogel, and "conformal" scanning mode. By using equilibrium swelling phenomenon of protein material itself, environmental stimuli responsive lasing peak wavelengths are experimentally demonstrated via changing the concentration of salt in water environment. In this way, the "double" designability and controllability have been achieved.III. Protein-based nanowire optical waveguides act as the pH sensor. We changed the method "bottom-up" assembly process which used in the past, using the inversion processing, Protein-based nanowire optical waveguides are FsLDW-fabricated in the low refractive index substrate: magnesium fluoride. Not only making use of basic characteristic of the material itself, but also through loading the FITC(Fluorescein Isothiocyanate), the micro-nano waveguide has been successfully achieved on pH sensing and test.