TY - GEN
T1 - Stacking-layer-number dependence of highly stacked InAs quantum dot laser diodes fabricated using strain-compensation technique
AU - Akahane, Kouichi
AU - Yamamoto, Naokatsu
AU - Kawanishi, Tetsuya
AU - Bietti, Sergio
AU - Takata, Ayami
AU - Okada, Yoshitaka
PY - 2012/3/1
Y1 - 2012/3/1
N2 - Semiconductor quantum dots (QDs) grown using self-assembly techniques in the Stranski- Krastanov (S-K) mode are expected to be useful for high-performance optical devices such as QD lasers. A significant amount of research has been carried out on the development of highperformance QD lasers because they offer the advantages of a low threshold current, temperature stability, high modulation bandwidth, and low chirp. To realize these high-performance devices, the surface QD density should be increased by fabricating a stacked structure. We have developed a growth method based on a strain-compensation technique that enables the fabrication of a high number of stacked InAs QD layers on an InP(311)B substrate. In this study, we employed the proposed method to fabricate QD laser diodes consisting of highly stacked QD layers and investigated the dependence of the diode parameters on the stacking layer number. We fabricated QD laser diodes with 5, 10, 15, and 20 QD layers in the active region. All of the laser diodes operated at around 1.55 μm at room temperature, and their threshold currents showed clear dependence on the stacking layer number. Laser diodes with more than 10 QD layers showed sufficient gain, i.e., the threshold currents decreased with a decrease in the cavity length. On the other hand, for laser diodes with less than 10 QD layers, the threshold currents increased with a decrease in the cavity length.
AB - Semiconductor quantum dots (QDs) grown using self-assembly techniques in the Stranski- Krastanov (S-K) mode are expected to be useful for high-performance optical devices such as QD lasers. A significant amount of research has been carried out on the development of highperformance QD lasers because they offer the advantages of a low threshold current, temperature stability, high modulation bandwidth, and low chirp. To realize these high-performance devices, the surface QD density should be increased by fabricating a stacked structure. We have developed a growth method based on a strain-compensation technique that enables the fabrication of a high number of stacked InAs QD layers on an InP(311)B substrate. In this study, we employed the proposed method to fabricate QD laser diodes consisting of highly stacked QD layers and investigated the dependence of the diode parameters on the stacking layer number. We fabricated QD laser diodes with 5, 10, 15, and 20 QD layers in the active region. All of the laser diodes operated at around 1.55 μm at room temperature, and their threshold currents showed clear dependence on the stacking layer number. Laser diodes with more than 10 QD layers showed sufficient gain, i.e., the threshold currents decreased with a decrease in the cavity length. On the other hand, for laser diodes with less than 10 QD layers, the threshold currents increased with a decrease in the cavity length.
KW - Highly stacking
KW - Quantum dot
KW - Semiconductor laser
KW - Strain-compensation
UR - http://www.scopus.com/inward/record.url?scp=84857494189&partnerID=8YFLogxK
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U2 - 10.1117/12.907533
DO - 10.1117/12.907533
M3 - Conference contribution
AN - SCOPUS:84857494189
SN - 9780819489203
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Novel In-Plane Semiconductor Lasers XI
T2 - Novel In-Plane Semiconductor Lasers XI
Y2 - 23 January 2012 through 26 January 2012
ER -