Journal of the Institute of Electronics Engineers of Korea SD (대한전자공학회논문지SD)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Facet Reflectivities as a Function of Waveguide width of Buried Channel Waveguides using the Field Profiles Obtained by the Variational Method

Variational 방법으로 구한 필드 분포를 이용한 도파로 폭에 따른 Buried Channel Waveguides의 단면 반사율

  • Kim, Sang-Taek (School of Electronic Engineering, Soongsil University) ;
  • Kim, Dong-Hoo (School of Electronic Engineering, Soongsil University) ;
  • Kim, Boo-Gyoun (School of Electronic Engineering, Soongsil University)
  • 김상택 (崇實大學校 情報通信電子工學部) ;
  • 김동후 (崇實大學校 情報通信電子工學部) ;
  • 김부균 (崇實大學校 情報通信電子工學部)
  • Published : 2000.11.01
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Abstract

We calculate the facet reflectivity as a function of the waveguide width of buried channel waveguides using the angular spectrum method and the field profiles obtained by the effective index method, the variational method and the modified variational method, respectively and discuss the results. As the waveguide width increases, the facet reflectivity of buried channel waveguides approaches to that of slab waveguides. As the waveguide width decreases, the facet reflectivity of quasi-TE mode decreases from that of slab waveguides, while that of quasi-TE mode increases from that of slab waveguides. The variation of the facet reflectivity of quasi-TE mode as a function of waveguide width is much larger than that of quasi-TM mode. When the aspect ratio is one, the difference between the facet reflectivity of quasi-TE mode and that of quasi-TM mode using the variational method and the modified variational method is negligible, while the difference between the facet reflectivity of quasi-TE mode and that of quasi-TM mode using the effective index method is large. In the case of quasi-TE mode, the facet reflectivity using the angular spectrum method and the field profiles obtained by the modified variational method could be more accurate than that obtained by the effective method. In the case of quasi-TM mode, the facet reflectivities obtained by the various methods are almost the same.

Buried channel waveguides의 필드 분포에 대한 analytic 표현식을 effective index method (EIM), variational method(VM)와 각각의 방향으로의 경계조건을 적용한 variational method (VM_vec)를 사용하여 구한 뒤 angular spectrum 방법을 적용하여 도파로 폭에 따른 단면 반사율을 계산하고 이를 비교 검토하였다. 도파로 폭이 커질수록 buried channel waveguides의 단면 반사율은 slab 도파로의 단면 반사율에 접근하였고 도파로 폭이 작아질수록 slab 도파로의 단면 반사율로부터 quasi-TE 모드의 단면 반사율은 감소하였고 quasi-TM 모드의 단면 반사율은 증가하였다. 도파로 폭에 따른 단면 반사율 변화량은 quasi-TM 모드보다 quasi-TE 모드에 대한 변화량이 크게 나타남을 알 수 있었다. Aspect ratio가 1일 때 VM과 VM_vec으로 구한 quasi-TE 모드와 quasi-TM 모드와 quasi-TM 모드의 반사율은 차이가 크게 나타났다. Quasi-TE 모드의 경우는 VM_vec으로 구한 필드 분포에 angular spectrum 방법을 적용하여 계산한 단면 반사율이 EIM으로 구한 반사율보다 정확한 값임을 알 수 있었고 quasi-TM 모드의 경우는 각 방법으로 구한 반사율이 거의 같음을 볼 수 있었다.

Keywords

References

  1. 김용곤, 김부균, 주홍로, 다층 구조 도파관 소자 단면에의 무반사 코팅 설계, 한국 통신학회 논문지, 제 21권, 제 7호, pp. 1850-1860, 1996
  2. Jens Buus, Mark C. Farries, and David J. Robbins, Reflectivity of Coated and Tilted Semiconductor Facets, IEEE. J. Quantum Electron., vol. 27, NO. 6, pp. 1837-1842, 1991 https://doi.org/10.1109/3.90013
  3. S. Kitamura, K. Komatsu and M. Kitaura, Polarization-Insensitive Semiconductor Optical Amplifier Array Grown by Selective MOVPE, IEEE Photon. Technol. Lett., vol. 6 no. 2, pp. 173-175, 1994 https://doi.org/10.1109/68.275419
  4. Y. Inoue, K. Katoh, and M. Kawachi, Polarization sensitivity of a silica waveguide thermooptic phase shifter for planar lightwave circuits, IEEE Photon. Technol. Lett., vol. 4, pp. 36-38, Jan. 1992 https://doi.org/10.1109/68.124868
  5. Kenji Kawano, Tsutou Kitoh, Masaki Kohtoku, Tatsuya Takeshita, and Yuji Hasumi, 3-D Semivectorial Analysis to Calculate Facet Reflectivities of Semiconductor Optical waveguide Based on the Bi-Directional method of Line BPM (MoL-BPM), IEEE Photon. Technol. Lett., vol. 10, no. 1, pp. 108-110, 1998 https://doi.org/10.1109/68.651125
  6. W. P. Huang, and H. A. Haus, A simple variational approach to optical rib waveguide, J. Lightwave Technol., vol. 9 no. 1, pp. 56-61, 1991 https://doi.org/10.1109/50.64923
  7. A. Kumar, K. Thyayarajan and A. K. Ghatak, Analysis of rectangular-core dielectric waveguide: An accurate perturbation approach, Opt. Lett., vol. 8, pp. 63-65, 1983
  8. BeamPROP, Version 4.0, RSoft Inc., 1999