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OPTICS LETTERS / Vol. 40, No. 9 / May 1, 2015
Ultracompact and broadband polarization beam splitter based on polarization-dependent critical guiding condition Zhoufeng Ying,1 Guanghui Wang,1,* Xuping Zhang,1 Ho-pui Ho,2 and Ying Huang3 1 2 3
Institute of Optical Communication Engineering, Nanjing University, Jiangsu 210009, China
Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore *Corresponding author: [email protected] Received February 11, 2015; revised April 9, 2015; accepted April 9, 2015; posted April 10, 2015 (Doc. ID 234489); published May 1, 2015
An ultracompact and broadband polarization beam splitter (PBS) based on the polarization-dependent critical guiding condition of an asymmetrical directional coupler is proposed. The device consists of a pair of silicon waveguides with different height and width. Due to the different cutoff conditions for the TE and TM polarization modes, it is possible to have the TM mode guided in one waveguide while the TE mode is supported in both. Therefore, only the phase-matching condition for the cross-coupling of the TE mode needs to be considered. This approach not only simplifies the design procedures but also significantly improves device performance with smaller total length and larger bandwidth. Finally, regardless of the contribution of S-bend waveguides, our proposed PBS has a coupling region as short as 0.2 μm, which is the shortest reported until now. The simulation result shows that the extinction ratios for the TE and TM polarization are 13.5 and 16.6 dB at their respective output ports, and their insertion losses are 0.29 and 0.13 dB, respectively. Numerical simulations also show that the device offers a very large bandwidth (∼140 nm) with large extinction ratio (>10 dB) and low insertion loss (10 dB) and a low insertion loss (10 dB. This work was supported by National Natural Science Foundation of China (No. 61308118). References 1. C.-L. Zou, F.-W. Sun, C.-H. Dong, X.-F. Ren, J.-M. Cui, X.-D. Chen, Z.-F. Han, and G.-C. Guo, Opt. Lett. 36, 3630 (2011). 2. Y. Huang, S. Zhu, H. Zhang, T.-Y. Liow, and G.-Q. Lo, Opt. Express 21, 12790 (2013). 3. M. Alam, J. S. Aitchison, and M. Mojahedi, Opt. Lett. 37, 55 (2012). 4. Z. Ying, G. Wang, X. Zhang, Y. Huang, H.-p. Ho, and Y. Zhang, IEEE Photon. Technol. Lett. 27, 201 (2015). 5. H. Zhang, S. Das, J. Zhang, Y. Huang, C. Li, S. Chen, H. Zhou, M. Yu, P. G.-Q. Lo, and J. T. Thong, Appl. Phys. Lett. 101, 021105 (2012). 6. A. Hosseini, S. Rahimi, X. Xu, D. Kwong, J. Covey, and R. Chen, Opt. Lett. 36, 4047 (2011). 7. L. Augustin, R. Hanfoug, J. Van der Tol, W. De Laat, and M. Smit, IEEE Photon. Technol. Lett. 19, 1286 (2007). 8. D. Dai, Z. Wang, and J. E. Bowers, Opt. Lett. 36, 2590 (2011). 9. X. Guan, H. Wu, Y. Shi, L. Wosinski, and D. Dai, Opt. Lett. 38, 3005 (2013). 10. F. Lou, D. Dai, and L. Wosinski, Opt. Lett. 37, 3372 (2012). 11. T. Yamazaki, H. Aono, J. Yamauchi, and H. Nakano, J. Lightwave Technol. 26, 3528 (2008). 12. D. Dai and J. E. Bowers, Opt. Express 19, 18614 (2011). 13. Z. Wang, Y. Tang, and S. He, IEEE Photon. Technol. Lett. 22, 1568 (2010).
OPTICS LETTERS / Vol. 40, No. 9 / May 1, 2015
Ultracompact and broadband polarization beam splitter based on polarization-dependent critical guiding condition Zhoufeng Ying,1 Guanghui Wang,1,* Xuping Zhang,1 Ho-pui Ho,2 and Ying Huang3 1 2 3
Institute of Optical Communication Engineering, Nanjing University, Jiangsu 210009, China
Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore *Corresponding author: [email protected] Received February 11, 2015; revised April 9, 2015; accepted April 9, 2015; posted April 10, 2015 (Doc. ID 234489); published May 1, 2015
An ultracompact and broadband polarization beam splitter (PBS) based on the polarization-dependent critical guiding condition of an asymmetrical directional coupler is proposed. The device consists of a pair of silicon waveguides with different height and width. Due to the different cutoff conditions for the TE and TM polarization modes, it is possible to have the TM mode guided in one waveguide while the TE mode is supported in both. Therefore, only the phase-matching condition for the cross-coupling of the TE mode needs to be considered. This approach not only simplifies the design procedures but also significantly improves device performance with smaller total length and larger bandwidth. Finally, regardless of the contribution of S-bend waveguides, our proposed PBS has a coupling region as short as 0.2 μm, which is the shortest reported until now. The simulation result shows that the extinction ratios for the TE and TM polarization are 13.5 and 16.6 dB at their respective output ports, and their insertion losses are 0.29 and 0.13 dB, respectively. Numerical simulations also show that the device offers a very large bandwidth (∼140 nm) with large extinction ratio (>10 dB) and low insertion loss (10 dB) and a low insertion loss (10 dB. This work was supported by National Natural Science Foundation of China (No. 61308118). References 1. C.-L. Zou, F.-W. Sun, C.-H. Dong, X.-F. Ren, J.-M. Cui, X.-D. Chen, Z.-F. Han, and G.-C. Guo, Opt. Lett. 36, 3630 (2011). 2. Y. Huang, S. Zhu, H. Zhang, T.-Y. Liow, and G.-Q. Lo, Opt. Express 21, 12790 (2013). 3. M. Alam, J. S. Aitchison, and M. Mojahedi, Opt. Lett. 37, 55 (2012). 4. Z. Ying, G. Wang, X. Zhang, Y. Huang, H.-p. Ho, and Y. Zhang, IEEE Photon. Technol. Lett. 27, 201 (2015). 5. H. Zhang, S. Das, J. Zhang, Y. Huang, C. Li, S. Chen, H. Zhou, M. Yu, P. G.-Q. Lo, and J. T. Thong, Appl. Phys. Lett. 101, 021105 (2012). 6. A. Hosseini, S. Rahimi, X. Xu, D. Kwong, J. Covey, and R. Chen, Opt. Lett. 36, 4047 (2011). 7. L. Augustin, R. Hanfoug, J. Van der Tol, W. De Laat, and M. Smit, IEEE Photon. Technol. Lett. 19, 1286 (2007). 8. D. Dai, Z. Wang, and J. E. Bowers, Opt. Lett. 36, 2590 (2011). 9. X. Guan, H. Wu, Y. Shi, L. Wosinski, and D. Dai, Opt. Lett. 38, 3005 (2013). 10. F. Lou, D. Dai, and L. Wosinski, Opt. Lett. 37, 3372 (2012). 11. T. Yamazaki, H. Aono, J. Yamauchi, and H. Nakano, J. Lightwave Technol. 26, 3528 (2008). 12. D. Dai and J. E. Bowers, Opt. Express 19, 18614 (2011). 13. Z. Wang, Y. Tang, and S. He, IEEE Photon. Technol. Lett. 22, 1568 (2010).
