TY - JOUR A1 - Roth, Gian-Luca A1 - Hessler, Steffen A1 - Kefer, Stefan A1 - Girschikofsky, Maiko A1 - Esen, Cemal A1 - Hellmann, Ralf T1 - Femtosecond laser inscription of waveguides and Bragg gratings in transparent cyclic olefin copolymers JF - Optics Express N2 - We report on a femtosecond laser based fabrication technique that enables simultaneous single-step generation of optical waveguides and Bragg gratings inside bulk cyclic olefin copolymers. Due to the nonlinear absorption of focused and spatially modulated laser radiation with a wavelength of 514 nm and a pulse duration of 450 fs, a modification concluding a refractive index shift increase inside the substrate can be achieved. A sophisticated characterization of the generated waveguides by means of an elaborate cut-back method reveals a maximum attenuation of 3.2 dB/cm. Additionally, a Mach-Zehnder interferometer is used to examine the waveguide’s refractive index profile. The integrated Bragg grating structures exhibit reflectivities up to 95 % and a spectral full width at half maximum of 288 pm, at a Bragg wavelength of 1582 nm, whereas the grating period can be deliberately chosen by adapting the fabrication parameters. Thus, due to its increased flexibility and the resulting dispensability of cost-intensive phase masks, this method constitutes an especially promising fabrication process for polymer Bragg gratings inside of bulk materials. KW - Femtosekundenlaser KW - Wellenleiter KW - Bragg-Reflektor Y1 - 2020 U6 - https://doi.org/10.1364/OE.388364 VL - 28 IS - 12 SP - 18077 EP - 18084 ER -