| 1. |
- Lin, Zongxing, et al.
(författare)
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High-Performance Silicon Polarization Beam Splitter Assisted by the Sub-Wavelength Structures
- 2023
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 35:23, s. 1267-1270
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Tidskriftsartikel (refereegranskat)abstract
- A high-performance polarization beam splitter(PBS) is proposed and experimentally demonstrated on the220-nm silicon-on-insulator (SOI) platform. The proposed PBSconsists of a sub-wavelength grating (SWG) assisted adiabaticdirectional coupler (ADC) and a simple filter at the throughport of the ADC. The SWG structures embedded in the ADCcan suppress and enhance the optical field evolutions of thefundamental TE and TM modes (referred to as TE and TMmodes in short), respectively, thus enhancing the separation ofthese two modes. The simple filter composed of four Euler bendsis used to further improve the polarization extinction ratio (PER)of the TM mode while maintaining low insertion loss (IL) forthe TE mode. The simulated results show that our proposedPBS possesses the high performance of IL<0.3 dB and PER>30 dB for both the TE and TM modes over the bandwidthof 1.46-1.625 mu m, which covers the most important S, C, and,L bands for optical communications. The experimental resultsshow that the fabricated PBS has excellent performance of IL<0.8 dB and PER>24.5 dB over the bandwidth of 1.53-1.61 mu m
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| 2. |
- Lin, Zongxing, et al.
(författare)
-
Using Photonic Crystal Microrings to Mitigate Raman-Kerr Effects Competition for Soliton Microcomb Generation
- 2024
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 42:1, s. 268-275
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Tidskriftsartikel (refereegranskat)abstract
- In nonlinear microresonators with strong stimulated Raman scattering effect, it is difficult if not impossible to generate Kerr soliton microcombs with a small free spectral range (FSR) (< 100 GHz) due to the competition between the Raman and Kerr effects. In this article, we overcome this limitation by using odd-period photonic crystal microrings (PCMs). Numerical simulations on the silicon-on-insulator (SOI) PCM show that a small frequency shift (5 GHz) induced by the photonic crystal structure can moderately suppress the Raman effect, such that chaotic microcombs with a small FSR can be generated. With a larger frequency shift (e.g., >= 10 GHz), the Raman effect is significantly suppressed, and the soliton microcombs can be generated. For comparison, without the frequency shift, only Raman lasing can be achieved in a conventional microring. To investigate the applicability of the proposed method in other material platforms, we carried out simulations for the aluminium nitride (AlN) PCM. The results are comparable to those obtained on the SOI PCM. Our method opens a new approach to the generation of small FSR Kerr soliton microcombs in microresonators with strong Raman effect, which is important for expanding the available nonlinear platforms and applications such as telecommunications, radio-frequency photonics, and astronomical spectrographs.
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