[show abstract][hide abstract] ABSTRACT: Tunable dual-mode lasing is experimentally demonstrated in a 1310-nm quantum dot (QD) distributed-feedback (DFB) laser under single-beam optical injection. The wavelength spacing between the two lasing modes is controlled by injecting the external optical signal into different residual Fabry-Perot modes of the QD DFB laser. The influence of important parameters, i.e., injection strength and bias current, is also analyzed. The simple experimental configuration used to achieve tunable dual-mode lasing and the theoretically superior properties of the QD laser offer exciting prospects for the use of these devices in microwave signal generation and radio-over-fiber applications for future mobile communication networks.
[show abstract][hide abstract] ABSTRACT: Tunable microwave signal generation with frequencies ranging from below 1 GHz to values over 40 GHz is demonstrated experimentally with a 1310nm Quantum Dot (QD) Distributed-Feedback (DFB) laser. Microwave signal generation is achieved using the period 1 dynamics induced in the QD DFB under optical injection. Continuous tuning in the positive detuning frequency range of the quantum dot's unique stability map is demonstrated. The simplicity of the experimental configuration offers promise for novel uses of these nanostructure lasers in Radio-over-Fiber (RoF) applications and future mobile networks.
[show abstract][hide abstract] ABSTRACT: We present the first elastic, space division multiplexing, and multi-granular network based on two 7-core MCF links and four programmable optical nodes able to switch traffic utilising the space, frequency and time dimensions with over 6000-fold bandwidth granularity. Results show good end-to-end performance on all channels with power penalties between 0.75 dB and 3.7 dB.
[show abstract][hide abstract] ABSTRACT: We report a first experimental observation of two-wavelength switching
(2WS) and bistability with a 1310nm-Quantum Dot (QDot) Distributed
Feedback (DFB) laser subject to external optical injection and operated
in reflection. We experimentally demonstrate the switching of the
emission wavelength of the QDot laser when an external optical signal is
injected into one of the subsidiary longitudinally modes located in the
longer wavelength side of the device's lasing mode. Clockwise nonlinear
switching and bistability are attained in all cases for both the
emitting and the injected mode of the QDot laser as the injection
strength is increased. Moreover, very high on-off contrast ratio is
measured in the switching (and bistability) transition of the emission
mode of the device. We have also analysed the switching properties of
the 1310-QDot DFB laser as a function of the applied bias current and
the initial wavelength detuning between the wavelengths of the external
signal and that of the device's injected mode. In general, wider
bistable loops, higher on-off contrast ratio between output states and
higher input power requirements for switching are observed as the
applied bias and initial detuning are increased. This diversity of
switching behaviors obtained with a 1310 QDot DFB laser under external
optical injection, added to the theoretically superior properties of
nanostructure lasers, offers exciting prospects for novel uses of these
devices in all-optical logic and all-optical switching/routing
applications in present and future optical telecommunication networks.
[show abstract][hide abstract] ABSTRACT: Two-wavelength switching operation and bistability is reported for the first time with a 1310-nm quantum-dot (QD) distributed feedback (DFB) laser. We demonstrate experimentally the switching of the lasing mode of the QD laser under external optical injection into one of the residual Fabry-Perot (FP) modes of the device. Clockwise switching and bistability occurs for both the lasing and the injected subsidiary modes of the QD DFB laser as the injection strength is increased. Moreover, very high ON-OFF contrast ratio is measured for the switching transition of the lasing mode of the device. We have also analyzed experimentally the influence of two important system parameters, namely the initial wavelength detuning and the applied bias current. The variety of switching behaviors obtained with a 1310-nm QD DFB laser added to the theoretically superior properties of nanostructure lasers offers exciting prospects for novel uses of these devices in all-optical logic and all-optical switching/routing applications in present and future optical telecommunication networks.
IEEE Journal of Selected Topics in Quantum Electronics 02/2013; 19(4):1900708. · 4.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: Generation of tunable millimeter-wave (MMW) and terahertz (THz) signals is experimentally demonstrated with an optically injected 1310-nm quantum dot distributed feedback (QD DFB) laser. A novel technique for MMW and THz signal generation is proposed, which is based on the dual-mode laser operation and the four-wave mixing induced in the QD DFB under single-beam optical injection into one of its residual Fabry-Perot modes. Coarse and fine tunability of the MMW and THz signals from 117 to 954 GHz is also demonstrated by injecting the external light into different residual modes of the QD laser and by controlling the injection strength and the initial frequency detuning.
[show abstract][hide abstract] ABSTRACT: New theoretical results are presented on polarized optical injection of vertical-cavity surface-emitting lasers (VCSELs) based on the spin-flip model extended to consider both the azimuth and ellipticity of the injected light. Experiments to investigate these effects are performed on two 1550-nm VCSELs with different frequency spacing between the resonances of the orthogonal polarizations of the fundamental transverse mode. Excellent agreement is found between experiment and theory for the stability and polarizations of the two VCSELs subject to polarized optical injection. The input polarization angle has a strong effect on both the dynamics and polarization of each VCSEL, whereas the ellipticity of the injected light affects only the polarization.
IEEE Journal of Selected Topics in Quantum Electronics 01/2013; 19(4):1700512-1700512. · 4.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this paper, we present detailed measurements of the temperature-dependent relaxation oscillation frequency and polarization resolved linewidth enhancement factor (α) of a 1550-nm vertical cavity surface emitting laser (VCSEL). The thermal effects on these parameters are investigated for a temperature range of -20°C to 60°C. Comparison is made between the experimental observations and theoretical predictions for similar VCSELs and with those different in operating wavelength and/or materials.
[show abstract][hide abstract] ABSTRACT: We report on the experimental observation of optical bistability (OB) and nonlinear switching (NS) in a nanostructure laser; specifically a 1550 nm quantum dash Fabry-Perot laser subject to external optical injection and operated in reflection. Different shapes of optical bistability and nonlinear switching, anticlockwise and clockwise, with very high on-off contrast ratio (up to 180:1) between output states were experimentally measured. These results added to the potential of nanostructure lasers for enhanced performance offer promise for use in fast all-optical signal processing applications in optical networks.
[show abstract][hide abstract] ABSTRACT: Presented are experimental observations on the occurrence of rare disruptive events in the polarisation resolved dynamics of 1550 nm vertical cavity surface-emitting lasers (VCSELs) when subject to orthogonally polarised optical injection. These events, characterised by high amplitude pulses, appeared individually and simultaneously in the two orthogonal polarisations of the fundamental transverse mode of the device. They could be observed in different regions of dynamic behaviour, including stable injection locking and chaos.
[show abstract][hide abstract] ABSTRACT: A modified spin-flip model is used to investigate the stability of optically-pumped quantum-dot spin-vertical cavity surface-emitting lasers. in terms of pump intensity and polarization. The stability maps exhibit pronounced polarization switching in the stable regions. Periodic oscillations in unstable regions are attributed to competition between spin relaxation and birefringence.
[show abstract][hide abstract] ABSTRACT: Optical injection is one of the key methods for invoking nonlinear
dynamical outputs in laser systems. The system parameters that are used
to control the nature of the output from such a system are the injection
strength and the frequency detuning between the optical frequency of the
free running master and slave lasers. A map of the dynamics can be
generated using a number of measurands to facilitate identifying the
fundamentally different dynamical regions in the
injection-strength/frequency-detuning parameter space. Herein we
describe a set of automated algorithms used to establish several
measures to identify transients and instabilities in the nonlinear
dynamical output of an optically injected vertical cavity surface
emitting laser (VCSEL), for set and unchanging driving parameters.
[show abstract][hide abstract] ABSTRACT: Automated protocols have been developed to characterize time series data in terms of stability. These techniques are applied to the output power time series of an optically injected vertical cavity surface emitting laser (VCSEL) subject to varying injection strength and optical frequency detuning between master and slave lasers. Dynamic maps, generated from high resolution, computer controlled experiments, identify regions of dynamic instability in the parameter space.
[show abstract][hide abstract] ABSTRACT: We report an approach based upon vertical cavity surface emitting lasers (VCSELs) to reproduce optically different behaviors exhibited by biological neurons but on a much faster timescale. The technique proposed is based on the polarization switching and nonlinear dynamics induced in a single VCSEL under polarized optical injection. The particular attributes of VCSELs and the simple experimental configuration used in this work offer prospects of fast, reconfigurable processing elements with excellent fan-out and scaling potentials for use in future computational paradigms and artificial neural networks.
[show abstract][hide abstract] ABSTRACT: We report the first room temperature optical spin-injection of a dilute nitride 1300 nm vertical-cavity surface-emitting laser (VCSEL) under continuous-wave optical pumping. We also present a novel experimental protocol for the investigation of optical spin-injection with a fiber setup. The experimental results indicate that the VCSEL polarization can be controlled by the pump polarization, and the measured behavior is in excellent agreement with theoretical predictions using the spin flip model. The ability to control the polarization of a long-wavelength VCSEL at room temperature emitting at the wavelength of 1.3 µm opens up a new exciting research avenue for novel uses in disparate fields of technology ranging from spintronics to optical telecommunication networks.
[show abstract][hide abstract] ABSTRACT: We analyze the time dependent dynamics associated with the Polarization
Switching (PS) induced in a 1550nm-Vertical Cavity Surface Emitting
Laser (VCSEL) subject to polarized optical injection. We have
investigated two different experimental configurations, namely single
and double polarized optical injection into the 1550nm-VCSEL with
polarizations parallel and orthogonal to that of the light emitted by
the solitary device. We have simultaneously analyzed the temporal
dynamics for the two orthogonal polarizations at the VCSEL output.
Sub-ns response times were obtained for both experimental
configurations. For single orthogonally-polarized optical injection we
found that the operation speed is ultimately limited by the relaxation
oscillation frequency of the VCSEL. On the other hand, with the device
subject to double polarized optical injection a significantly enhanced
operation speed was obtained. We believe that this improved time
response is due to the faster carrier dynamics associated with the
switching between the two injectionlocked states induced alternatively
by the two polarized optically-injected signals. This enhanced operation
speed for the PS attained in VCSELs at the important telecom wavelength
of 1550nm offers exciting prospects for novel uses of these devices in
optical signal processing and optical switching applications in present
and future optical networks.
[show abstract][hide abstract] ABSTRACT: The dynamic transition in a photonic integrated circuit—the change from linear-nonlinear-linear dynamics, in dependence on specific system parameters is shown both experimentally, and for a modeled device using a travelling-wave method. The nature of the dynamic throughout the transition is defined using a correlation dimension method, and good agreement between the experiment and theory is shown, both in terms of the mean, and the standard deviation of the correlation dimension. A unique time-window used with the correlation dimension method provides new insight into the temporal variation of the dynamic throughout this transition.
[show abstract][hide abstract] ABSTRACT: We demonstrate for the first time an extended OpenFlow based control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet domains. We also demonstrate for the first time multi-domain network slicing and verified results on a global scale trial involving test-beds in UK, Spain and Japan.
38th European Conference on Optical Communication (ECOC 2012), PostDeadline, Th.3.D.3; 01/2012