Theoretical study on high-speed modulation of Fabry-Pérot and distributed-feedback quantum-dot lasers: K-factor-limited bandwidth and 10Gbit∕s eye diagrams

This paper presents a theoretical study of the high-speed modulation response of Fabry-Perot (FP) and distributed-feedback (DFB) quantum-dot lasers based on the rate equation models, making reference to available experimental data. We show that the K-factor-limited maximum modulation bandwidth increases with the maximum optical gain and that there is an optimum cavity loss to maximize the bandwidth at a given maximum gain, enabling us to design the bandwidth of FP lasers as well as DFB lasers with and without a phase shift. We present modulation wave forms of FP quantum-dot lasers to indicate that the maximum modal gain of 30–40cm−1 is sufficient for 10Gbit∕s eye opening, which explains the recent success of 10Gbit∕s modulation of the quantum-dot laser with ten dot layers in the active region having the maximum modal gain of 35cm−1. We show a design for low-driving-current 10Gbit∕s operation by shortening the cavity length with the optimum cavity loss maintained by the high-reflectivity coating.

[1]  N. Yokoyama,et al.  1.3-μm CW lasing of InGaAs-GaAs quantum dots at room temperature with a threshold current of 8 mA , 1999, IEEE Photonics Technology Letters.

[2]  Sasan Fathpour,et al.  High-speed quantum dot lasers , 2005 .

[3]  M. Ishida,et al.  Modeling room-temperature lasing spectra of 1.3-μm self-assembled InAs∕GaAs quantum-dot lasers: Homogeneous broadening of optical gain under current injection , 2005 .

[4]  Y. Arakawa,et al.  Theory of optical signal amplification and processing by quantum-dot semiconductor optical amplifiers , 2004 .

[5]  Joo-Heon Ahn,et al.  High temperature performance of self-organised quantum dot laser with stacked p-doped active region , 2002 .

[6]  D. Deppe,et al.  1.3 μm room-temperature GaAs-based quantum-dot laser , 1998 .

[7]  J. Carroll,et al.  Distributed feedback semiconductor lasers , 1998 .

[8]  H. Sakaki,et al.  Multidimensional quantum well laser and temperature dependence of its threshold current , 1982 .

[9]  Yasuhiko Arakawa,et al.  Temperature-Insensitive Eye-Opening under 10-Gb/s Modulation of 1.3-µm P-Doped Quantum-Dot Lasers without Current Adjustments , 2004 .

[10]  Y. Arakawa,et al.  Recent progress in self-assembled quantum-dot optical devices for optical telecommunication: temperature-insensitive 10 Gb s−1 directly modulated lasers and 40 Gb s−1 signal-regenerative amplifiers , 2005, 2006 Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference.

[11]  P. Bhattacharya,et al.  Tunnel injection In0.4Ga0.6As/GaAs quantum dot lasers with 15 GHz modulation bandwidth at room temperature , 2002 .

[12]  Haiyu Huang,et al.  Modulation characteristics of quantum-dot lasers: the influence of p-type doping and the electronic density of states on obtaining high speed , 2002 .

[13]  M. Sugawara,et al.  Self-Formed In0.5Ga0.5As Quantum Dots on GaAs Substrates Emitting at 1.3 µm , 1994 .

[14]  Y. Arakawa,et al.  Photon lifetime dependence of modulation efficiency and K factor in 1.3μm self-assembled InAs∕GaAs quantum-dot lasers: Impact of capture time and maximum modal gain on modulation bandwidth , 2004 .