Carrier dynamics and high-speed modulation properties of tunnel injection InGaAs-GaAs quantum-dot lasers

Pallab Bhattacharya; Siddhartha Ghosh; Sameer Pradhan; Jasprit Singh; Zong Kwei Wu; J. Urayama; Kyoungsik Kim; Theodore B. Norris

doi:10.1109/JQE.2003.814374

Carrier dynamics and high-speed modulation properties of tunnel injection InGaAs-GaAs quantum-dot lasers

Pallab Bhattacharya, Siddhartha Ghosh, Sameer Pradhan, Jasprit Singh, Zong Kwei Wu, J. Urayama, Kyoungsik Kim, Theodore B. Norris

Department of Mechanical Engineering

Research output: Contribution to journal › Article › peer-review

172 Citations (Scopus)

Abstract

We have performed pump-probe differential transmission spectroscopy (DTS) measurements on In_0.4Ga_0.6As-GaAs-AlGaAs heterostructures, which show that at room temperature, injected electrons preferentially occupy the excited states in the dots and states in the barriers layers. The relaxation time of these carriers to the dot ground state is > 100 ps. This leads to large gain compression in quantum-dot (QD) lasers and limits the attainable small-signal modulation bandwidth to ∼ 5-7 GHz. The problem can be alleviated by tunneling "cold" electrons into the lasing states of the dots from an adjoining injector layer. The design, growth, and steady-state and small-signal modulation characteristics of tunnel injection In_0.4Ga_0.6As-GaAs QD lasers are described and discussed. The tunneling times, directly measured by three-pulse DTS measurements, are ∼ 1.7 ps and independent of temperature. The measured small-signal modulation bandwidth for I/I_th ∼ 7 is f_-3dB = 23 GHz and the gain compression factor for this frequency response is ε = 8.2 × 10^-16 cm³. The differential gain obtained from the modulation data is dg/dn ≅ 2.7 × 10^-14 cm² at room temperature. The value of the K-factor is 0.205 ns and the maximum intrinsic modulation bandwidth is 43.3 GHz. Analysis of the transient characteristics with appropriate carrier and photon rate equations yield modulation response characteristics identical to the measured ones. The Auger coefficients are in the range ∼ 3.3 × 10^-29 cm⁶/s to 3.8 × 10^-29 cm⁶/s in the temperature range 15°C < T < 85°C, determined from large-signal modulation measurements, and these values are smaller than those measured in separate confinement heterostructure QD lasers. The measured high-speed data are comparable to, or better than, equivalent quantum-well lasers for the first time.

Original language	English
Pages (from-to)	952-962
Number of pages	11
Journal	IEEE Journal of Quantum Electronics
Volume	39
Issue number	8
DOIs	https://doi.org/10.1109/JQE.2003.814374
Publication status	Published - 2003 Aug

Bibliographical note

Funding Information:
Manuscript received November 4, 2002; revised March 10, 2003. The work was supported by the Army Research Office under Grant DAAD019-01-1-0331. The authors are with the Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109–2122 USA. Digital Object Identifier 10.1109/JQE.2003.814374

All Science Journal Classification (ASJC) codes

Atomic and Molecular Physics, and Optics
Condensed Matter Physics
Electrical and Electronic Engineering

Access to Document

10.1109/JQE.2003.814374

Cite this

@article{e1e3b33a387c4206b7dd373aed8544be,

title = "Carrier dynamics and high-speed modulation properties of tunnel injection InGaAs-GaAs quantum-dot lasers",

abstract = "We have performed pump-probe differential transmission spectroscopy (DTS) measurements on In0.4Ga0.6As-GaAs-AlGaAs heterostructures, which show that at room temperature, injected electrons preferentially occupy the excited states in the dots and states in the barriers layers. The relaxation time of these carriers to the dot ground state is > 100 ps. This leads to large gain compression in quantum-dot (QD) lasers and limits the attainable small-signal modulation bandwidth to ∼ 5-7 GHz. The problem can be alleviated by tunneling {"}cold{"} electrons into the lasing states of the dots from an adjoining injector layer. The design, growth, and steady-state and small-signal modulation characteristics of tunnel injection In0.4Ga0.6As-GaAs QD lasers are described and discussed. The tunneling times, directly measured by three-pulse DTS measurements, are ∼ 1.7 ps and independent of temperature. The measured small-signal modulation bandwidth for I/Ith ∼ 7 is f-3dB = 23 GHz and the gain compression factor for this frequency response is ε = 8.2 × 10-16 cm3. The differential gain obtained from the modulation data is dg/dn ≅ 2.7 × 10-14 cm2 at room temperature. The value of the K-factor is 0.205 ns and the maximum intrinsic modulation bandwidth is 43.3 GHz. Analysis of the transient characteristics with appropriate carrier and photon rate equations yield modulation response characteristics identical to the measured ones. The Auger coefficients are in the range ∼ 3.3 × 10-29 cm6/s to 3.8 × 10-29 cm6/s in the temperature range 15°C < T < 85°C, determined from large-signal modulation measurements, and these values are smaller than those measured in separate confinement heterostructure QD lasers. The measured high-speed data are comparable to, or better than, equivalent quantum-well lasers for the first time.",

author = "Pallab Bhattacharya and Siddhartha Ghosh and Sameer Pradhan and Jasprit Singh and Wu, {Zong Kwei} and J. Urayama and Kyoungsik Kim and Norris, {Theodore B.}",

note = "Funding Information: Manuscript received November 4, 2002; revised March 10, 2003. The work was supported by the Army Research Office under Grant DAAD019-01-1-0331. The authors are with the Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109–2122 USA. Digital Object Identifier 10.1109/JQE.2003.814374",

year = "2003",

month = aug,

doi = "10.1109/JQE.2003.814374",

language = "English",

volume = "39",

pages = "952--962",

journal = "IEEE Journal of Quantum Electronics",

issn = "0018-9197",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "8",

}

TY - JOUR

T1 - Carrier dynamics and high-speed modulation properties of tunnel injection InGaAs-GaAs quantum-dot lasers

AU - Bhattacharya, Pallab

AU - Ghosh, Siddhartha

AU - Pradhan, Sameer

AU - Singh, Jasprit

AU - Wu, Zong Kwei

AU - Urayama, J.

AU - Kim, Kyoungsik

AU - Norris, Theodore B.

N1 - Funding Information: Manuscript received November 4, 2002; revised March 10, 2003. The work was supported by the Army Research Office under Grant DAAD019-01-1-0331. The authors are with the Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109–2122 USA. Digital Object Identifier 10.1109/JQE.2003.814374

PY - 2003/8

Y1 - 2003/8

N2 - We have performed pump-probe differential transmission spectroscopy (DTS) measurements on In0.4Ga0.6As-GaAs-AlGaAs heterostructures, which show that at room temperature, injected electrons preferentially occupy the excited states in the dots and states in the barriers layers. The relaxation time of these carriers to the dot ground state is > 100 ps. This leads to large gain compression in quantum-dot (QD) lasers and limits the attainable small-signal modulation bandwidth to ∼ 5-7 GHz. The problem can be alleviated by tunneling "cold" electrons into the lasing states of the dots from an adjoining injector layer. The design, growth, and steady-state and small-signal modulation characteristics of tunnel injection In0.4Ga0.6As-GaAs QD lasers are described and discussed. The tunneling times, directly measured by three-pulse DTS measurements, are ∼ 1.7 ps and independent of temperature. The measured small-signal modulation bandwidth for I/Ith ∼ 7 is f-3dB = 23 GHz and the gain compression factor for this frequency response is ε = 8.2 × 10-16 cm3. The differential gain obtained from the modulation data is dg/dn ≅ 2.7 × 10-14 cm2 at room temperature. The value of the K-factor is 0.205 ns and the maximum intrinsic modulation bandwidth is 43.3 GHz. Analysis of the transient characteristics with appropriate carrier and photon rate equations yield modulation response characteristics identical to the measured ones. The Auger coefficients are in the range ∼ 3.3 × 10-29 cm6/s to 3.8 × 10-29 cm6/s in the temperature range 15°C < T < 85°C, determined from large-signal modulation measurements, and these values are smaller than those measured in separate confinement heterostructure QD lasers. The measured high-speed data are comparable to, or better than, equivalent quantum-well lasers for the first time.

AB - We have performed pump-probe differential transmission spectroscopy (DTS) measurements on In0.4Ga0.6As-GaAs-AlGaAs heterostructures, which show that at room temperature, injected electrons preferentially occupy the excited states in the dots and states in the barriers layers. The relaxation time of these carriers to the dot ground state is > 100 ps. This leads to large gain compression in quantum-dot (QD) lasers and limits the attainable small-signal modulation bandwidth to ∼ 5-7 GHz. The problem can be alleviated by tunneling "cold" electrons into the lasing states of the dots from an adjoining injector layer. The design, growth, and steady-state and small-signal modulation characteristics of tunnel injection In0.4Ga0.6As-GaAs QD lasers are described and discussed. The tunneling times, directly measured by three-pulse DTS measurements, are ∼ 1.7 ps and independent of temperature. The measured small-signal modulation bandwidth for I/Ith ∼ 7 is f-3dB = 23 GHz and the gain compression factor for this frequency response is ε = 8.2 × 10-16 cm3. The differential gain obtained from the modulation data is dg/dn ≅ 2.7 × 10-14 cm2 at room temperature. The value of the K-factor is 0.205 ns and the maximum intrinsic modulation bandwidth is 43.3 GHz. Analysis of the transient characteristics with appropriate carrier and photon rate equations yield modulation response characteristics identical to the measured ones. The Auger coefficients are in the range ∼ 3.3 × 10-29 cm6/s to 3.8 × 10-29 cm6/s in the temperature range 15°C < T < 85°C, determined from large-signal modulation measurements, and these values are smaller than those measured in separate confinement heterostructure QD lasers. The measured high-speed data are comparable to, or better than, equivalent quantum-well lasers for the first time.

UR - http://www.scopus.com/inward/record.url?scp=0043173950&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0043173950&partnerID=8YFLogxK

U2 - 10.1109/JQE.2003.814374

DO - 10.1109/JQE.2003.814374

M3 - Article

AN - SCOPUS:0043173950

SN - 0018-9197

VL - 39

SP - 952

EP - 962

JO - IEEE Journal of Quantum Electronics

JF - IEEE Journal of Quantum Electronics

IS - 8

ER -

Carrier dynamics and high-speed modulation properties of tunnel injection InGaAs-GaAs quantum-dot lasers

Abstract

Bibliographical note

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Fingerprint

Cite this