We report on a novel waveguide-based polarization beam splitter (PBS) fabricated by femtosecond (fs) laser in lithium niobate (LiNbO ₃ ) crystals. This monolithic PBS is composed of tailored waveguide configurations with different guiding properties in which linearly polarized light along extraordinary refractive index ( n_e ) and ordinary index ( n_o ) can be well separated. At the wavelength of 1064 nm, polarization extinction ratio (PER) can reach to 16.60 dB and 16.18 dB for n_e and n_o polarizations, with insertion loss (IL) of 3.86 dB and 4.15 dB respectively. Our work may pave a new way for designing high-performance PBS and creating compact polarization conversion systems in integrated photonics and quantum photonics.

中文翻译：

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飞秒激光刻制的新型波导分束器

我们报告了飞秒（fs）激光在铌酸锂（LiNbO ₃ ）晶体中制造的新型基于波导的偏振分束器（PBS） 。这种整体式PBS由具有不同引导特性的量身定制的波导配置组成，其中线性偏振光沿非凡的折射率（ ñ _ë ）和普通索引（ ñ _Ø ）可以很好地分开。在1064 nm的波长下，偏振消光比（PER）可以达到16.60 dB，而对于ñ _ë 和 ñ _Ø极化，插入损耗（IL）分别为3.86 dB和4.15 dB。我们的工作可能为在集成光子学和量子光子学中设计高性能PBS并创建紧凑的偏振转换系统铺平道路。