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Optimization of Optical Coupling Properties of Active-Passive Butt Joint Structure in InP-Based Ridge Waveguide

InP계 리지 도파로 구조에서 활성층-수동층 버트 조인트의 광결합 효율 최적화 연구

  • Received : 2020.12.10
  • Accepted : 2020.12.22
  • Published : 2020.12.30

Abstract

Integration of active and passive waveguides is an essential component of the photonic integrated circuit and its elements. Butt joint is one of the important technologies to accomplish it with significant advantages. However, it suffers from high optical loss at the butt joint junction and need of accurate process control to align both waveguides. In this study, we used beam propagation method to simulate an integrated device composed of a laser diode and spot size converter (SSC). Two SSCs with different mode properties were combined with laser waveguide and optical coupling efficiency was simulated. The SSC with larger near field mode showed lower coupling efficiency, however its far field pattern was narrower and more symmetric. Tapered passive waveguide was utilized for enhancing the coupling efficiency and tolerance of waveguide offset at the butt joint without degrading the far field pattern. With this technique, high optical coupling efficiency of 89.6% with narrow far field divergence angle of 16°×16° was obtained.

활성 도파로와 수동 도파로의 집적은 광집적 회로의 구성에서 필수적인 요소이다. 이를 구현하기 위한 여러 기술 중 버트 조인트는 상당한 장점을 가지고 있다. 그러나 버트 조인트 접합은 높은 광손실을 야기하며, 두 도파로 간의 정렬에 있어서 정확한 공정 제어가 요구되는 구조이다. 본 논문에서는 레이저 다이오드와 spot size converter (SSC)로 구성된 집적 소자를 시뮬레이션하기 위해 beam propagation method을 이용하였다. 상이한 모드 특성을 갖는 두 SSC를 레이저 도파로와 연결하고, 광결합 효율을 시뮬레이션 하였다. 큰 근접장 모드를 가지는 SSC는 낮은 광결합 효율을 보여주나, 원거리 발산각 패턴이 좁고 더 대칭적이다. 테이퍼 구조의 수동 도파로는 원거리 발산각 패턴을 열화시키지 않고 버트 조인트에서 도파로 오프셋의 무의존성과 광결합 효율을 향상시키기 위해 이용되었다. 이를 바탕으로 89.6%의 높은 광결합 효율과 16°×16°의 좁은 원거리장 발산각을 얻을 수 있었다.

Keywords

References

  1. Cisco, "Cisco visual networking index: global mobile data traffic forecast update, 2017-2022", Cisco Systems, Inc., (2019) from https://s3.amazonaws.com/media.mediapost.com/uploads/CiscoForecast.pdf
  2. Y. C. Chung, "Fiber-optic Communications-Historical Perspectives and Future Directions(in Kor.)", Korean J. Opt. Photon., 29(5), 187 (2018). https://doi.org/10.3807/KJOP.2018.29.5.187
  3. H. J. Kang, T. Kim, and M. Y. Jeong, "PLC devices fabricated on flexible plastic substrate by roll-to-roll imprint lithography", J. Microelectron. Packag. Soc., 22(4), 25 (2015). https://doi.org/10.6117/kmeps.2015.22.4.025
  4. J. Park, D. Lee, H. Rho, S. Kim, J. Heo, S. Ryu, S. J. Kang, and J. S. Ha, "Research on Fabrication of Silicon Lens for Optical Communication by Photolithography Process", J. Microelectron. Packag. Soc., 25(2), 35 (2018). https://doi.org/10.6117/KMEPS.2018.25.2.035
  5. W. Kobayashi, M. Arial, T. Yamanaka, N. Fujiwara, T. Fujisawa, T. Tadokoro, K. Tsuzuki, Y. Kondo, and F. Kano, "Design and fabrication of 10-/40-Gb/s, uncooled electroabsorption modulator integrated DFB laser with butt-joint structure", J. Light. Technol., 28(1), 164 (2010). https://doi.org/10.1109/JLT.2009.2036865
  6. K. Shinoda, S. Makino, T. Kitatani, T. Shiota, T. Fukamachi, and M. Aoki, "InGaAlAs-InGaAsP heteromaterial monolithic integration for advanced long-wavelength optoelectronic devices", IEEE J. Quantum Electron., 45(9), 1201 (2009). https://doi.org/10.1109/JQE.2009.2020304
  7. J. Van Roey, J. Van Der Donk, and P. E. Lagasse, "Beampropagation method: analysis and assessment", J. Opt. Soc. Am., 71(7), 803 (1981). https://doi.org/10.1364/JOSA.71.000803
  8. W. P. Huang and C. L. Xu, "Simulation of three-dimensional optical waveguides by a full-vector beam propagation method", IEEE J. Quantum Electron., 29(10), 2639 (1993). https://doi.org/10.1109/3.250386
  9. G. R. Hadley, "Wide-angle beam propagation using Pade approximant operators", Opt. Lett., 17(20), 1426 (1992). https://doi.org/10.1364/OL.17.001426
  10. I. Ilic, R. Scarmozzino, and R. M. Osgood, "Investigation of the Pade approximant-based wide-angle beam propagation method for accurate modeling of waveguiding circuits", J. Light. Technol., 14(12), 2813 (1996). https://doi.org/10.1109/50.545802
  11. C. R. Pollock, "Fundamentals of optoelectronics", pp.299-301, Tom Casson, Chicago (1995).
  12. G. R. Hadley, "Transparent boundary condition for the beam propagation method", IEEE J. Quantum Electron. 28(1), 363 (1992). https://doi.org/10.1109/3.119536
  13. S. K. Selvaraja and P. Sethi, "Review on optical waveguides", Emerging Waveguide Technology, 95 (2018).
  14. T. Aalto, K. Solehmainen, M. Harjanne, M. Kapulainen, and P. Heimala, "Low-loss converters between optical silicon waveguides of different sizes and types", IEEE Photon. Technol. Lett., 18(5), 709 (2006). https://doi.org/10.1109/LPT.2006.871150
  15. J. Heinrich, E. Zeeb, and K. J. Ebeling, "Butt-coupling efficiency of VCSELs into multimode fibers", IEEE Photon Technol. Lett., 9(12), 1555 (1997). https://doi.org/10.1109/68.643258
  16. K. T. Kim, K. H. Park, W. K. Hyun, Y. Jung, and B. H. Lee, "Mode Size Converter based on Muitimode Fiber Taper(in Kor.)", Korean J. Opt. Photon., 18(4), 280 (2007). https://doi.org/10.3807/HKH.2007.18.4.280
  17. Y. Fu, T. Ye, W. Tang, and T. Chu, "Efficient adiabatic silicon-on-insulator waveguide taper", Photonics Res., 2(3), 41 (2014).