Subwavelength-grating-assisted broadband polarization-independent directional coupler

This Letter presents both numerical and experimental results of a polarization-independent directional coupler based on slot waveguides with a subwavelength grating. The measured coupling efficiency is 97.4% for TE and 96.7% for TM polarization at a wavelength of 1550 nm. Further analysis shows that...

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Bibliographic Details
Published inOptics letters Vol. 41; no. 7; p. 1648
Main Authors Liu, Lu, Deng, Qingzhong, Zhou, Zhiping
Format Journal Article
LanguageEnglish
Published United States 01.04.2016
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Summary:This Letter presents both numerical and experimental results of a polarization-independent directional coupler based on slot waveguides with a subwavelength grating. The measured coupling efficiency is 97.4% for TE and 96.7% for TM polarization at a wavelength of 1550 nm. Further analysis shows that the proposed subwavelength grating directional coupler has a fabrication tolerance of ±20  nm for the grating structure and that the coupling efficiencies for the two polarizations are both higher than -0.5  dB (∼89%), exceeding the entire C-band (1525-1570 nm) experimentally.
ISSN:1539-4794
DOI:10.1364/ol.41.001648