2026-09-14T13:30:39Zhttps://gredos.usal.es/oai/request

oai:gredos.usal.es:10366/1468852025-04-30T20:35:22Zcom_10366_133237com_10366_4512com_10366_3823col_10366_133238

00925njm 22002777a 4500 dc Nie, Weijie author Jia, Yuechen author Vázquez de Aldana, Javier R. author Chen, Feng author 2016-02 Integrated photonic devices with beam splitting function are intriguing for a broad range of photonic applications. Through optical-lattice-like cladding waveguide structures fabricated by direct femtosecond laser writing, the light propagation can be engineered via the track-confined refractive index profiles, achieving tailored output beam distributions. In this work, we report on the fabrication of 3D laser-written optical-lattice-like structures in a nonlinear KTP crystal to implement 1 × 4 beam splitting. Second harmonic generation (SHG) of green light through these nonlinear waveguide beam splitter structures provides the capability for the compact visible laser emitting devices. With Type II phase matching of the fundamental wavelength (@ 1064 nm) to second harmonic waves (@ 532 nm), the frequency doubling has been achieved through this three-dimensional beam splitter. Under 1064-nm continuous-wave fundamental-wavelength pump beam, guided-wave SHG at 532 nm are measured with the maximum power of 0.65 mW and 0.48 mW for waveguide splitters (0.67 mW and 0.51 mW for corresponding straight channel waveguides), corresponding to a SH conversion efficiency of approximately ~14.3%/W and 13.9%/W (11.2%/W, 11.3%/W for corresponding straight channel waveguides), respectively. This work paves a way to fabricate compact integrated nonlinear photonic devices in a single chip with beam dividing functions. Nie, W., Jia, Y., Vázquez de Aldana, J. et al. Efficient Second Harmonic Generation in 3D Nonlinear Optical-Lattice-Like Cladding Waveguide Splitters by Femtosecond Laser Inscription. Sci Rep 6, 22310 (2016). https://doi.org/10.1038/srep22310 http://hdl.handle.net/10366/146885 10.1038/srep22310 2045-2322 Integrated optics devices Laser material processing Efficient Second Harmonic Generation in 3D Nonlinear Optical-Lattice-Like Cladding Waveguide Splitters by Femtosecond Laser Inscription