### Abstract

1. 5- mu m asymmetric lambda /4-shifted InGaAsP/InP DFB (distributed feedback) lasers in which the lambda /4-shift position was moved from the center of the DFB region toward the front side were made in order to obtain higher output power with high single-longitudinal-mode (SLM) yield. Statistical measurements showed that for an increase of the differential quantum efficiency from the front facet without a noticeable decrease of the SLM yield, the lambda /4-shift position should be moved toward the front facet by 10-15% of the total DFB length. The output efficiencies of diodes with AR coatings on the window structure were almost coincident to those expected from theoretical calculations. The main-to-submode ratio P//0/P//1 in the rear spectra of the asymmetric devices noticeably decreased with increasing asymmetry. From an experimental point of view, a criterion for stable SLM operation, for example, P//0/P//1 greater than equivalent to 1. 5 in the rear spectrum at I equals 0. 9I//t//h for the lambda /4-shift position l//f:l//r equals 35:65, is presented.

Original language | English |
---|---|

Pages (from-to) | 815-821 |

Number of pages | 7 |

Journal | IEEE Journal of Quantum Electronics |

Volume | QE-23 |

Issue number | 6 |

Publication status | Published - 1987 Jun |

Externally published | Yes |

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### ASJC Scopus subject areas

- Electrical and Electronic Engineering
- Physics and Astronomy (miscellaneous)

### Cite this

*IEEE Journal of Quantum Electronics*,

*QE-23*(6), 815-821.

**ASYMMETRIC lambda /4-SHIFTED InGaAsP/InP DFB LASERS.** / Usami, Masashi; Akiba, Shigeyuki; Utaka, Katsuyuki.

Research output: Contribution to journal › Article

*IEEE Journal of Quantum Electronics*, vol. QE-23, no. 6, pp. 815-821.

}

TY - JOUR

T1 - ASYMMETRIC lambda /4-SHIFTED InGaAsP/InP DFB LASERS.

AU - Usami, Masashi

AU - Akiba, Shigeyuki

AU - Utaka, Katsuyuki

PY - 1987/6

Y1 - 1987/6

N2 - 1. 5- mu m asymmetric lambda /4-shifted InGaAsP/InP DFB (distributed feedback) lasers in which the lambda /4-shift position was moved from the center of the DFB region toward the front side were made in order to obtain higher output power with high single-longitudinal-mode (SLM) yield. Statistical measurements showed that for an increase of the differential quantum efficiency from the front facet without a noticeable decrease of the SLM yield, the lambda /4-shift position should be moved toward the front facet by 10-15% of the total DFB length. The output efficiencies of diodes with AR coatings on the window structure were almost coincident to those expected from theoretical calculations. The main-to-submode ratio P//0/P//1 in the rear spectra of the asymmetric devices noticeably decreased with increasing asymmetry. From an experimental point of view, a criterion for stable SLM operation, for example, P//0/P//1 greater than equivalent to 1. 5 in the rear spectrum at I equals 0. 9I//t//h for the lambda /4-shift position l//f:l//r equals 35:65, is presented.

AB - 1. 5- mu m asymmetric lambda /4-shifted InGaAsP/InP DFB (distributed feedback) lasers in which the lambda /4-shift position was moved from the center of the DFB region toward the front side were made in order to obtain higher output power with high single-longitudinal-mode (SLM) yield. Statistical measurements showed that for an increase of the differential quantum efficiency from the front facet without a noticeable decrease of the SLM yield, the lambda /4-shift position should be moved toward the front facet by 10-15% of the total DFB length. The output efficiencies of diodes with AR coatings on the window structure were almost coincident to those expected from theoretical calculations. The main-to-submode ratio P//0/P//1 in the rear spectra of the asymmetric devices noticeably decreased with increasing asymmetry. From an experimental point of view, a criterion for stable SLM operation, for example, P//0/P//1 greater than equivalent to 1. 5 in the rear spectrum at I equals 0. 9I//t//h for the lambda /4-shift position l//f:l//r equals 35:65, is presented.

UR - http://www.scopus.com/inward/record.url?scp=0023363910&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023363910&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0023363910

VL - QE-23

SP - 815

EP - 821

JO - IEEE Journal of Quantum Electronics

JF - IEEE Journal of Quantum Electronics

SN - 0018-9197

IS - 6

ER -