### Abstract

Electron and hole diffusions in the plane of semiconductor quantum wells play an important part in the static and dynamic operations of semiconductor lasers. It is well known that the value of diffusion coefficients affects the threshold pumping current of a semiconductor laser. At the same time, the strength of carrier diffusion process is expected to affect the modulation bandwidth of an AC-modulated laser. It is important not only to investigate the combined DC and AC effects due to carrier diffusion, but also to separate the AC effects from that of the combined effects in order to provide design insights for high speed modulation. In this presentation, we apply a hydrodynamic model developed by the present authors recently from the semiconductor Bloch equations. The model allows microscopic calculation of the lateral carrier diffusion coefficient, which is a nonlinear function of the carrier density and plasma temperature. We first studied combined AC and DC effects of lateral carrier diffusion by studying the bandwidth dependence on diffusion coefficient at a given DC current under small signal modulation. The results show an increase of modulation bandwidth with decrease in the diffusion coefficient. We simultaneously studied the effects of nonlinearity in the diffusion coefficient. To clearly identify how much of the bandwidth increase is a result of decrease in the threshold pumping current for smaller diffusion coefficient, thus an effective increase of DC pumping, we study the bandwidth dependence on diffusion coefficient at a given relative pumping. A detailed comparison of the two cases will be presented.

Original language | English (US) |
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Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering |

Editors | R.H. Binder, P. Blood, M. Osinski, Y. Arakawa |

Pages | 293-301 |

Number of pages | 9 |

Volume | 4646 |

DOIs | |

State | Published - 2002 |

Externally published | Yes |

Event | Physics and Simulation of Optoelectronic Devices X - San Jose, CA, United States Duration: Jan 21 2002 → Jan 25 2002 |

### Other

Other | Physics and Simulation of Optoelectronic Devices X |
---|---|

Country | United States |

City | San Jose, CA |

Period | 1/21/02 → 1/25/02 |

### Fingerprint

### Keywords

- Carrier diffusion
- Current modulation
- Nonlinearity
- Semiconductor laser

### ASJC Scopus subject areas

- Electrical and Electronic Engineering
- Condensed Matter Physics

### Cite this

*Proceedings of SPIE - The International Society for Optical Engineering*(Vol. 4646, pp. 293-301) https://doi.org/10.1117/12.470528

**Static and dynamic effects of lateral carrier diffusion in semiconductor lasers.** / Li, Jianzhong; Cheung, Samson H.; Ning, Cun-Zheng.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*Proceedings of SPIE - The International Society for Optical Engineering.*vol. 4646, pp. 293-301, Physics and Simulation of Optoelectronic Devices X, San Jose, CA, United States, 1/21/02. https://doi.org/10.1117/12.470528

}

TY - GEN

T1 - Static and dynamic effects of lateral carrier diffusion in semiconductor lasers

AU - Li, Jianzhong

AU - Cheung, Samson H.

AU - Ning, Cun-Zheng

PY - 2002

Y1 - 2002

N2 - Electron and hole diffusions in the plane of semiconductor quantum wells play an important part in the static and dynamic operations of semiconductor lasers. It is well known that the value of diffusion coefficients affects the threshold pumping current of a semiconductor laser. At the same time, the strength of carrier diffusion process is expected to affect the modulation bandwidth of an AC-modulated laser. It is important not only to investigate the combined DC and AC effects due to carrier diffusion, but also to separate the AC effects from that of the combined effects in order to provide design insights for high speed modulation. In this presentation, we apply a hydrodynamic model developed by the present authors recently from the semiconductor Bloch equations. The model allows microscopic calculation of the lateral carrier diffusion coefficient, which is a nonlinear function of the carrier density and plasma temperature. We first studied combined AC and DC effects of lateral carrier diffusion by studying the bandwidth dependence on diffusion coefficient at a given DC current under small signal modulation. The results show an increase of modulation bandwidth with decrease in the diffusion coefficient. We simultaneously studied the effects of nonlinearity in the diffusion coefficient. To clearly identify how much of the bandwidth increase is a result of decrease in the threshold pumping current for smaller diffusion coefficient, thus an effective increase of DC pumping, we study the bandwidth dependence on diffusion coefficient at a given relative pumping. A detailed comparison of the two cases will be presented.

AB - Electron and hole diffusions in the plane of semiconductor quantum wells play an important part in the static and dynamic operations of semiconductor lasers. It is well known that the value of diffusion coefficients affects the threshold pumping current of a semiconductor laser. At the same time, the strength of carrier diffusion process is expected to affect the modulation bandwidth of an AC-modulated laser. It is important not only to investigate the combined DC and AC effects due to carrier diffusion, but also to separate the AC effects from that of the combined effects in order to provide design insights for high speed modulation. In this presentation, we apply a hydrodynamic model developed by the present authors recently from the semiconductor Bloch equations. The model allows microscopic calculation of the lateral carrier diffusion coefficient, which is a nonlinear function of the carrier density and plasma temperature. We first studied combined AC and DC effects of lateral carrier diffusion by studying the bandwidth dependence on diffusion coefficient at a given DC current under small signal modulation. The results show an increase of modulation bandwidth with decrease in the diffusion coefficient. We simultaneously studied the effects of nonlinearity in the diffusion coefficient. To clearly identify how much of the bandwidth increase is a result of decrease in the threshold pumping current for smaller diffusion coefficient, thus an effective increase of DC pumping, we study the bandwidth dependence on diffusion coefficient at a given relative pumping. A detailed comparison of the two cases will be presented.

KW - Carrier diffusion

KW - Current modulation

KW - Nonlinearity

KW - Semiconductor laser

UR - http://www.scopus.com/inward/record.url?scp=0036028299&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036028299&partnerID=8YFLogxK

U2 - 10.1117/12.470528

DO - 10.1117/12.470528

M3 - Conference contribution

AN - SCOPUS:0036028299

VL - 4646

SP - 293

EP - 301

BT - Proceedings of SPIE - The International Society for Optical Engineering

A2 - Binder, R.H.

A2 - Blood, P.

A2 - Osinski, M.

A2 - Arakawa, Y.

ER -