High speed nanophotonic devices based on quantum dots

Abstract

For InAs‐GaAs based quantum dot lasers emitting at 1300 nm digital modulation with bit error rates below 10–11 at –2 dBm receiver power is demonstrated. Error rates of 10–9 or better are realized between 23 °C and 70 °C without current adjustment. Passive and hybrid mode‐locked QD lasers are shown to generate optical pulses with repetition frequencies up to 80 GHz and 40 GHz, respectively, with an ultra‐short minimum pulse length of 710 fs at 20 GHz. The minimum root mean square jitter of 40 GHz hybrid mode‐locked pulses is found to be 400 fs with a corresponding pulse width of 4 ps. Quantum dot based 1.3 µm fiber‐coupled amplifier modules show 40 Gb/s operation with bit error rates below 10–11. Amplifier chip gain up to 26 dB is demonstrated. 710 fs pulses are amplified without pulse broadening. For all devices we use deeply etched narrow ridge waveguide structures which show excellent current and optical confinement. Along with suppressed beam filamentation of the fundamental mode, a low α ‐factor and strongly reduced sensitivity to optical feedback our results demonstrate that QD laser performance is now comparable or even superior to quantum well lasers. These achievements became possible due to systematic devel‐opment of self‐organized growth technologies. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Hybrid Mode Locking in Semiconductor Lasers: Simulations, Analysis, and Experiments

“…These lasers are very promising for local area networks or optical clocks operating at 1.3 μm. Due to the presence of spontaneous emission and other noise sources, pulses emitted by passively ML lasers usually exhibit a considerable timing jitter can be of the order of 10 ps for 40-GHz ML lasers [3]. An effective method for suppressing this jitter down to hundreds of femtoseconds is based on hybrid mode locking [3], [4].…”

“…Due to the presence of spontaneous emission and other noise sources, pulses emitted by passively ML lasers usually exhibit a considerable timing jitter can be of the order of 10 ps for 40-GHz ML lasers [3]. An effective method for suppressing this jitter down to hundreds of femtoseconds is based on hybrid mode locking [3], [4]. In hybrid ML lasers, the reverse bias applied to the saturable absorber (SA) section is modulated at the frequency f M close to the pulse repetition frequency f P of the free-running passively ML laser [4]- [9].…”

New Approaches to Perform All-Optical Signal Regeneration

“…And indeed, there is not a single highest-speed (160 Gb/s and above) wavelength conversion or regeneration experiment with an SOA-MZI configuration (There are 160 Gb/s to 40 Gb/s demultiplexing experiments with SOA-MZIs -but then the repetition rate is 40 GHz only). 2.2 QD-SOA Self-assembled quantum dot (QD) semiconductor optical amplifiers (SOA) are another promising choice for building all-optical devices for signal processing with sub-l0 ps response times [5]. Here, we consider InAs/GaAs QD SOA as they exhibit low sensitivity with respect to temperature and show potential for uncooled operation at 1.3 ptm.…”

Electronic and optical properties of InGaAs/GaAs quantum dots with tunable aspect-ratio

“…And the surface morphology contribution to the optical properties is significant. [14][15][16] The composition profiles depend strongly on the morphological features, strain ratio and growth environment. Therefore, it is very necessary to obtain the exact equilibrium composition profiles.…”