-
[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.
Optics Express 05/2013; 21(9):10772-8. · 3.59 Impact Factor
-
[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.
Optics Express 02/2012; 20(4):3550-5. · 3.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report a new approach to mimic basic functionalities of a neuron using a 1550 nm Vertical Cavity Surface Emitting Laser (VCSEL) which is based on the polarisation switching (PS) that can be induced in these devices when subject to polarised optical injection. Positive and negative all-optical threshold operations are demonstrated experimentally using external optical injection into the two orthogonal polarizations of the fundamental transverse mode. The polarisation of the light emitted by the device is used to determine the state of the VCSEL-Neuron, active (orthogonal) or inactive (parallel). This approach forms a new way to reproduce optically the response of a neuron to an excitatory and an inhibitory stimulus.
Optics Express 11/2010; 18(24):25170-6. · 3.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report a first experimental study of the nonlinear dynamics appearing in a 1550 nm single-mode VCSEL subject to parallel and to orthogonal optical injection. For the first time to our knowledge we report experimentally measured stability maps identifying the boundaries between regions of different nonlinear dynamics for both cases of polarized injection. A rich variety of nonlinear behaviours, including periodic (limit cycle, period doubling) and chaotic dynamics have been experimentally observed.
Optics Express 04/2010; 18(9):9423-8. · 3.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We have measured optical power and wavelength polarization bistability in a 1550 nm-Vertical Cavity Surface-Emitting Laser (VCSEL) subject to orthogonally-polarized optical injection into the orthogonal polarization of the fundamental transverse mode. Optical bistability with very wide hysteresis cycles, up to four times wider than previously reported results has been measured for both the optical power and wavelength domain. We also report the experimental observation of three different shapes of polarization bistability, anticlockwise, clockwise and X-Shape bistability, all of them with wide hysteresis cycles. This rich variety of behaviour at the important wavelength of 1550 nm offers promise for the use of VCSELs for all-optical signal processing and optical switching/routing applications.
Optics Express 12/2009; 17(26):23637-42. · 3.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Different forms of wavelength polarization switching and bistability are reported in a 1550 nm vertical-cavity surface-emitting laser (VCSEL) operated just above threshold and subject to orthogonally polarized optical injection into the subsidiary orthogonal polarization mode. This diversity of behavior at the wavelength of 1550 nm offers promise for the use of VCSELs in optical signal processing and optical switching applications.
Optics Letters 03/2009; 34(3):365-7. · 3.40 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report experimental measurements of power and wavelength optical bistability and nonlinear gain in two 1.55 μm vertical-cavity semiconductor optical amplifiers operated in reflection. Anticlockwise and clockwise nonlinear switching and bistability, both with high on-off contrast ratio up to 3.5:1, have been observed in the optical power and wavelength domains. Theoretical modeling gives excellent agreement with the experimental measurements.
Applied Physics Letters 10/2007; 91(15):151106-151106-3. · 3.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Experimental observation of Optical Bistability (OB) and nonlinear gain is reported in a 1550-nm Vertical Cavity Semiconductor Optical Amplifier (VCSOA) under parallel and orthogonal polarized optical injection into the two orthogonal polarizations of the fundamental mode. Different nonlinear switching mechanisms, including anticlockwise and clockwise nonlinear gain and bistability, have been found when the polarization of the externally injected signal matches that of the injected mode, whilst a linear response is measured when the polarization is orthogonal to that of the mode under injection. This diversity of behavior with input polarization offers promise for the potential use of VCSOAs for all-optical signal processing and all-optical switching/routing applications.
Optics Express 08/2007; 15(14):9084-9. · 3.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report experimental measurements of Optical Bistability (OB) and nonlinear switching in a 1550 nm-Vertical-Cavity Semiconductor Optical Amplifier (VCSOA) operated in reflection and biased below and above its threshold current. Two different types of OB and nonlinear switching, anticlockwise and clockwise, have been observed in both the optical power and wavelength domain. The influence of important parameters including the bias current, the initial wavelength detuning and the optical input power has also been studied. The existence of diverse forms of OB and nonlinear switching in a VCSOA operated in reflection opens the door for the development of inverting and non-inverting logic gates, using, respectively, the anticlockwise or the clockwise nonlinear switching transitions appearing in the VCSOA under external optical injection.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
05/2007;
-
[show abstract]
[hide abstract]
ABSTRACT: We report the static and dynamic properties of an all-optical inverter based on an 850 nm Vertical Cavity Semiconductor Optical Amplifier (VCSOA). The inverter exhibits low switching power requirements (~ 15 μW), large on/off contrast ratio (> 11 dB), and high speed operation (~ 1.4 GHz). Large and small signal measurements show that the speed of operation and the on/off contrast ratio improve with increased bias current. This holds important prospects for the development of VCSOA-inverters for high-speed, low-power optical logic applications. Finally, a theoretical model of the VCSOA-inverter has been employed giving good agreement with experiments.Research Highlights►We report the static and dynamic properties of an 850 nm VCSOA all-optical inverter. ►Inverter has low switching power (~ 15 μW) and large on/off contrast ratio (> 11 dB). ►Inverter has high speed operation (~ 1.4 GHz). ►Speed of operation and on/off contrast ratio improve with increased bias current. ►Theoretical model of VCSOA inverter shows good agreement with experiments.
Optics Communications 284(9):2345-2350. · 1.49 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We demonstrate theoretically and experimentally that the injection of two optical signals into a semiconductor laser can be a feasible and practical method of enhancing chaos, influencing the stability map and generating various nonlinear dynamics.
Optics Communications.
