New channel guiding structures via femtosecond laser direct writing z-cut LiNbO3 crystals

Autor: Jixin Liu, Hangjian Zhang, Siwen Ai, Quanxin Yang, Yingying Ren, Hongliang Liu
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Results in Physics, Vol 57, Iss , Pp 107379- (2024)
Druh dokumentu: article
ISSN: 2211-3797
DOI: 10.1016/j.rinp.2024.107379
Popis: In this work, we use femtosecond laser direct writing to fabricate two kinds of modified structures with opposite refractive index changes to build new dual-line waveguide configurations in z-cut LiNbO3 (LN) crystals for the first time. These hybrid-structure waveguides, in which type-Ⅰ modifications are induced between two type-Ⅱ tracks have been investigated by an end-face coupling system at 532 nm. The results indicate that TEM00 mode is the only transmission mode for all waveguides. Comparing with the single-modification waveguides, experimental results indicate that the new waveguides in which type-Ⅱ tracks with 12 μm interval exhibit lower transmission losses (about 0.98 dB/cm). The reasons for these interesting guiding performances are analyzed by the confocal micro-Raman results. The beam quality is measured in both directions (x and y) and also in the visible (532 nm) and infrared (1064 nm) regions. This work provides a new perspective for improving the transmission efficiency of waveguides, which is the new hybrid structure in LN crystals. The new-waveguides design method has potential application in the field of photonic chips.
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