Dependence of Extinction Ratio on the Carrier Transport in $1.55{\mu}m$ InGaAsP/InGaAsP Multiple-Quantum-Well Electroabsorption Modulators

$1.55{\mu}m$ InGaAsP/InGaAsP 다중양자우물구조 전계흡수형 광변조기에서 캐리어 수송현상이 소광특성에 미치는 영향

  • Shim, Jong-In (School of Electrical & Computer Science, Hanyang University) ;
  • Eo, Yung-Seon (School of Electrical & Computer Science, Hanyang University)
  • 심종인 (漢陽大學校 電子컴퓨터工學部) ;
  • 어영선 (漢陽大學校 電子컴퓨터工學部)
  • Published : 2000.09.01

Abstract

The effects of carrier transport and input power on the extinction ratio was theoretically analyzed in a 1.55${\mu}m$ InGaAsP/InGaAsP multiple-quantum-well(MQW) electroabsorption(EA) modulator. Poisson's equation, current continuity equations for electrons and holes, and optical field distribution were self-consistently solved by considering electric field dependent absorption coefficients. The field screening effect due to the carrier accumulation in heterointerface and the space-charge region occurred more seriously at the input side of modulator as input optical intensity increased. It was revealed that extinction ratio could be steeply degraded for modulator with the length of 200${\mu}m$ when an input power exceeds 10mW. A degradation of extinction ratio due to the field screening effect would be more significantly at high-performance devices such as a 1.55${\mu}m$DFB-LD/EA-modulator integrated source where optical coupling efficiency is almost complete or a very high-speed modulator with its length as short as a few tens ${\mu}m$.

1.55${\mu}m$ InGaAsP/InGaAsP 다중양자우물주고 전계흡수형 광변조기에서 캐리어 수송현상과 입력광 세기가 소광특성에 미치는 영향을 조사하였다. 포와송 방정식과 전자 및 정공의 전류 연속방정식, 광분포들을 양자우물에서의 전게강도에 따른 흡수계수들을 고러하여 self-consistent하게 해석하였다. 이종접합계면에서의 캐리어의 축적 및 광도파로영역에서의 공간전하에 의한 전계차폐 현상은 입사광 파워가 증가할 수록 입사단 영역에서 심하게 나타남을 알 수 있었다. 캐리어의 전계차폐에 의한 소광비 저감은 변조기가 길이가 200${\mu}m$정도로 긴 경우에는 입사광 파워가 약 10mW이상에 대해서 심하게 나타날 수 있음을 알 수 있었다. 이러한 캐리어의 전계차폐에 따른 소광비 특성열화는 특히 입사광 파워가 클 수 있는 1..55${\mu}m$ DFB-LD와 전계흡수형 광변조기 집적소자나 광변조기 길이가 수십 ${\mu}m$로 짧은 초고속 광흡수변조기의 경우에 더욱 심하게 나타날 수 있음을 지적하였다.

Keywords

References

  1. T. Ido, S. Tanaka, M. Suzuki, M. Koizumi, H. Sano, and H. Inoue, ' Ultra-high-speed multiple-Quantum-well electro-absorption optical modulators with integrated waveguides,' IEEE J. Lightwave Technol., vol.14, no.9, pp 2026-2034, Sep. 1996 https://doi.org/10.1109/50.536970
  2. F. Devaux, S. Chelles, A. Ougazzaden, A. Mircea, M. Carre, F. Huet, A. Carenco, Y. Sorel, J. F. Kerdiles, and M. Henry, 'Full polarization insensitivity of a 20Gb/s sLrained-MQW electroabsorption modulator,' IEEE Photonics Technol. Letters., vol.6, no. 10, pp. 1203-1205, 1994 https://doi.org/10.1109/68.329639
  3. R. M. Lammert, D. V. Forbes, G. M. Smith, M. L. Osowski, and J. J. Coleman, 'InGaAs-GaAs Quantum-Well lasers with monolitically integrated intracavity electroabsorption modulators bt selective-area MOCVD,' IEEE Photonics Technol. Letters., vol. 8, no. 1, pp. 78-80, 1996 https://doi.org/10.1109/68.475784
  4. H.Takeuchi, K.Tsuzuki, K.Sato, M.Yamamoto, Y. Itaya, A. Sano, M. Yoneyama, and T. Otsuji, ' Very high-speed light-source up to 40Gb/s containing an MQW electroabsorption modulator integrated with a DFB laser,' IEEE J. Quantum Electron., vol. 3, no. 2, pp. 336-343, Apr. 1997
  5. M. E. Watson, J. L. A. Chilla, J. J. Rocca, J.,-W. Kim, D. L.Lile, T. J. Vogt, and G. Y. Robinson, 'Saturation intensity and time response of InGaAs-inGaP MQW optical modulators,' IEEE J. Quantum. Electron., vol.31, no.2, pp. 254260, 1995 https://doi.org/10.1109/3.348053
  6. A. M. Fox, D. A. B. Miller, G. Livescu, J. E. Cunningham, and W. Y. Jan, 'Quantum well carrier sweep out: relation to electroabsorption and extinon saturation,' IEEE J. Quantum. Electron., vol.27, no.10, pp. 2281-2295, 1991 https://doi.org/10.1109/3.97272
  7. T. Ikeda and H. Hiroshi, 'Analysis of the attenuation ratio of MQW optical intensity modulator for 1.55 ${\mu}m$ wavelength taking account of electron wave function leakage,' IEEE J. Quantum. Electron., vol.32, no.2, pp. 284-292, 1995 https://doi.org/10.1109/3.481875
  8. D. Meglio, P. Lugli, R. Sabella, and O. Sahlen, 'Analysis and optimization of InGaAsP electro-absorption modulators,' IEEE J. Quantum. Electron., vol.31, no.4, pp. 169-177, 1995 https://doi.org/10.1109/3.348054
  9. M. Suzuki, H. Tanaka, and S. Akiba, 'Effect of hole pile-up at heterointerface on modulation voltage in InGaAsP electro-absorption modulators,' Electron. Lett., vol. 25, no. 2, pp. 88-89, 1988
  10. C. Glingener, D. Schulz, and E. Voges, 'Modeling of optical waveguide modulators on III-V semiconductors,' IEEE J Quantum Electron., vol.31, no.1, pp.101-112, 1995 https://doi.org/10.1109/3.341713
  11. P. J. Stevens, M. Whitehead, G. Parry, and K. Woodbridge, 'Computer modeling of the electric field dependent absorption spectrum of multiple quantum well material,' IEEE J. Quantum. Electron., vol.24, no.10, pp. 2007-2016, 1988 https://doi.org/10.1109/3.8536
  12. K.H. Chung and J.I. Shim, 'A new polarization insensitive $1.55{\mu}m$ InGaAs(P)InGaAsP multiquantum-well electroabsorption modulator using a strain-compensating layer,' IEEE J. Quantum. Electron., vol.35, no.5, pp.730-736, 1999 https://doi.org/10.1109/3.760319