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Showing papers on "Semiconductor optical gain published in 2013"


Journal ArticleDOI
TL;DR: The period-one (P1) nonlinear dynamics of a semiconductor laser subject to both optical injection and optical feedback are investigated for photonic microwave generation and a dual-loop optical feedback stabilizes the fluctuations of the oscillation frequency.
Abstract: The period-one (P1) nonlinear dynamics of a semiconductor laser subject to both optical injection and optical feedback are investigated for photonic microwave generation. The optical injection first drives the laser into P1 dynamics so that its intensity oscillates at a microwave frequency. A dual-loop optical feedback then stabilizes the fluctuations of the oscillation frequency. Photonic generation at 45.424 GHz is demonstrated with a linewidth below 50 kHz using a laser with a relaxation resonance frequency of only 7 GHz. The dual-loop feedback effectively narrows the linewidth by over an order of magnitude, reduces the phase noise variance by more than 500 times, and suppresses side peaks in the power spectrum.

110 citations


Book
20 May 2013
TL;DR: In this paper, the general properties of Nitrides are discussed, including the properties of metal contacts, the p-n junction, and the P-n Junction junction junction.
Abstract: 1. General Properties of Nitrides 2. Doping: Determination of Impurity and Carrier Concentrations 3. Metal Contacts 4. Carrier Transport 5. The p- n Junction 6. Optical Processes 7. Light-Emitting Diodes and Lighting 8. Semiconductor Lasers: Light Amplification by Stimulated Emission of Radiation 9. Field Effect Transistors

82 citations


Journal ArticleDOI
TL;DR: In this paper, the authors combined optical injection and polarization-rotated optical feedback in a semiconductor laser to induce self-referenced periodic output that is widely tunable by simply varying the dc bias points of the system's master and slave.
Abstract: Combining optical injection and polarization-rotated optical feedback in a semiconductor laser can induce self-referenced periodic output that is widely tunable by simply varying the dc-bias points of the system's master and slave lasers. We observed a feedback-induced reduction of the fundamental period-one oscillation linewidth by more than two orders of magnitude relative to the injection-only case. Performance was found to be negatively affected by the interference between the external injection signal and the residual feedback in the same polarization. The nonlinear dynamics of the optically injected semiconductor laser can be used to minimize sensitivity to fluctuations in the operating points. However, the use of the nonlinear dynamics at high oscillation frequencies is limited by the decreasing strength of the interaction between the circulating intracavity optical field and the carrier density.

66 citations


Journal ArticleDOI
TL;DR: This study investigates the period-one nonlinear dynamics of semiconductor lasers for optical modulation depth improvement to achieve photonic microwave amplification through modulation sideband enhancement to achieve radio-over-fiber links with high link gain.
Abstract: For radio-over-fiber links, microwave-modulated optical carriers with high optical modulation depth are preferred because high optical modulation depth allows generation of high microwave power after photodetection, leading to high detection sensitivity, long transmission distance, and large link gain. This study investigates the period-one nonlinear dynamics of semiconductor lasers for optical modulation depth improvement to achieve photonic microwave amplification through modulation sideband enhancement. In our scheme, only typical semiconductor lasers are required as the amplification unit. The amplification is achieved for a broad microwave range, from less than 25 GHz to more than 60 GHz, and for a wide gain range, from less than 10 dB to more than 30 dB. The microwave phase quality is mainly preserved while the microwave power is largely amplified, improving the signal-to-noise ratio up to at least 25 dB. The bit-error ratio at 1.25 Gbits/s is better than 10−9, and a sensitivity improvement of up to at least 15 dB is feasible.

48 citations


Journal ArticleDOI
TL;DR: An optically injected semiconductor laser at period-one nonlinear dynamics for optical DSB-to-SSB conversion can be self-adapted to certain changes in the operating microwave frequency and can operate stably under certain fluctuations in the input optical power and frequency.
Abstract: To distribute microwaves over fibers, optical single-sideband (SSB) modulation signals are preferred to optical double-sideband (DSB) modulation signals. This study investigates an optically injected semiconductor laser at period-one nonlinear dynamics for optical DSB-to-SSB conversion. For the operating microwave frequencies up to 40 GHz investigated in this study, the proposed system regenerates or even enhances the microwave features of an optical DSB input while converting its optical feature into SSB with an intensity difference of at least 20 dB. The bit-error ratio at 622 Mb/s is down to 10(-9) with a sensitivity improvement of up to 3 dB. The proposed system can be self-adapted to certain changes in the operating microwave frequency and can operate stably under certain fluctuations in the input optical power and frequency.

46 citations


Journal ArticleDOI
TL;DR: In this article, the effects of biaxial tensile stress and n-type doping on the direct-transition optical gain in germanium infrared lasers, in which three differently oriented systems of (0 0 1), (1 1 0) and ( 1 1 1) Ge are analysed.
Abstract: We investigate the effects of biaxial tensile stress and n-type doping on the direct-transition optical gain in germanium infrared lasers, in which three differently oriented systems of (0 0 1), (1 1 0) and (1 1 1) Ge are analysed. We show our theoretical model for the strain tensor, strained electronic band structure, carrier occupation, optical gain and free-carrier absorption to evaluate the net optical gain under different strain and n-doping levels. Our analysis shows that for a large strain, (0 0 1) Ge can produce a larger optical gain than the others due to its clear direct-bandgap behaviour for mid-infrared lasers. For a moderate strain combined with the use of n-type doping, (1 1 1) Ge can generate a larger net optical gain than the others for near-infrared lasers. Our modelling results provide an insight into the improvement of optical emission in Ge for lasers.

46 citations


Journal ArticleDOI
TL;DR: In this article, a new and novel scheme for a high speed all-optical half adder based on single Quantum-dot semiconductor optical amplifier (QD-SOA) assisted Mach-Zehnder interferometer (MZI) is theoretically investigated and discussed.
Abstract: A new and novel scheme for a high speed all-optical half adder based on single Quantum-dot semiconductor optical amplifier (QD-SOA) assisted Mach-Zehnder interferometer (MZI) is theoretically investigated and discussed. In this proposed scheme, pair of input data streams are simultaneously drive the switch to produce sum and carry. In this new design, only single switch can be utilized to design half adder circuit and no additional input beam is required other than two input signals. This design is simpler, smaller and compact than our previously proposed design . The impact of the peak data power as well as of the QD-SOAs current density and maximum modal gain on the ER, Q factor with current densities and electron relaxation times etc are explored and assessed by means of numerical simulations.

42 citations


Journal ArticleDOI
TL;DR: In this paper, the modulation properties of self-injected quantum-dot semiconductor lasers were investigated using a semianalytical approach, and the modulation characteristic of a quantum dot nanostructure laser operating under the influence of optical feedback was successfully modeled.
Abstract: This paper investigates the modulation properties of self-injected quantum-dot semiconductor lasers Using a semianalytical approach, the modulation characteristic of a quantum-dot nanostructure laser operating under the influence of optical feedback is successfully modeled This novel approach derives a feedback-induced modulation response model based on the incorporation of the specific quantum nanostructure carrier dynamics as well as the effects of nonlinear gain This study investigates the impacts of the carrier capture and relaxation time as well as other material parameters such as linewidth enhancement factor, differential gain, and gain compression factor for different feedback configurations It is also shown that, under the short external cavity configuration, the dynamic properties such as the relaxation frequency as well as the laser's bandwidth can be improved through controlled optical feedback On the other hand, numerical results show that under the long external cavity configuration, any small back-reflection from the laser's facets combined with the large variations of linewidth enhancement factor would significantly alter the laser's modulation response

42 citations


Proceedings ArticleDOI
12 May 2013
TL;DR: In this article, the authors numerically and experimentally demonstrate that, by combining two post-processing methods (multi-bit extraction and bitwise OR exclusive (XOR)) in a single chaotic semiconductor ring laser (SRL), it is possible to generate true random bits with a bit rate up to 40 Gb/s from a chaos bandwidth of ≈ 2 GHz.
Abstract: Here, we numerically and experimentally demonstrate that, by combining two post-processing methods (multi-bit extraction and bitwise OR-exclusive (XOR) operations). in a single chaotic semiconductor ring laser (SRL), it is possible to generate true random bits with a bit rate up to 40 Gb/s from a chaos bandwidth of ≈ 2 GHz, thanks to the device ability of lasing in two directional modes and the fact that the two mode signals have low correlations. In addition, SRLs can be easily implemented on chip.

41 citations


Journal ArticleDOI
TL;DR: In this paper, a scheme for the simultaneous reduction of time-bandwidth product (TBP) and RF linewidth of quantum-dash two-section mode-locked laser using optical injection-locking and filtered optical feedback was proposed.
Abstract: We introduce a novel scheme for the simultaneous reduction of time-bandwidth product (TBP) and RF linewidth of quantum-dash two-section mode-locked lasers using optical injection-locking and filtered optical feedback. The optical injection-locked laser, double-locked with optical feedback showed 2× TBP reduction and RF linewidth reduction by two orders of magnitude. This stabilization technique is implemented in an all-optical arrangement without optical/electrical conversion which is ideal for high-repetition-rate devices and photonic integration.

41 citations


Journal ArticleDOI
TL;DR: In this paper, an intracavity semiconductor optical parametric generator in multiple-quantum well AlGaAs/InGaAs Bragg reflection waveguide laser emitting between 986 and 995 nm was presented.
Abstract: We report on the characteristics of an intracavity semiconductor optical parametric generator in multiple-quantum well AlGaAs/InGaAs Bragg reflection waveguide lasers emitting between 986 and 995 nm. The cavity of the laser is phase-matched for down-conversion of pump photons to a signal between 1739 and 1767 nm and an idler between 2235 and 2328 nm. The normalized conversion efficiency is calculated to be 1.23×103 %W−1cm−2 above laser threshold and 1.25×104 %W−1cm−2 below threshold. The demonstrated device is potential for the realization of integrated parametric devices such as electrically pumped entangled photon-pair sources and optical parametric oscillation, where quantum optical effects can unfold.

Posted Content
H. Wenzel1
TL;DR: In this article, the authors review some of the models and solution techniques used in the simulation of high-power semiconductor lasers and to address open questions and reveal the factors that limit the output power at very high injecton currents based on a numerical solution of the thermodynamic based drift-diffusion equations.
Abstract: The aim of this paper is to review some of the models and solution techniques used in the simulation of high-power semiconductor lasers and to address open questions. We discuss some of the peculiarities in the description of the optical field of wide-aperture lasers. As an example, the role of the substrate as a competing waveguide in GaAs-based lasers is studied. The governing equations for the investigation of modal instabilities and filamentation effects are presented and the impact of the thermal-lensing effect on the spatiotemporal behavior of the optical field is demonstrated. We reveal the factors that limit the output power at very high injecton currents based on a numerical solution of the thermodynamic based drift-diffusion equations and elucidate the role of longitudinal spatial holeburning.

Journal ArticleDOI
TL;DR: The results revealing the influence of external optical feedback (EOF) on the alpha factor, or the linewidth enhancement factor, of semiconductor lasers operating on single mode are presented.
Abstract: This Letter presents the results revealing the influence of external optical feedback (EOF) on the alpha factor, or the linewidth enhancement factor, of semiconductor lasers operating on single mode. First, a method is proposed for the measurement of the alpha over a wide range of optical feedback level, which provides an effective way for investigating the dependence of the alpha on laser operating conditions. Second, experimental investigation based on the proposed method is performed on a GaAlAs laser diode with a multiquantum well structure. It is discovered that the alpha value remains approximately constant with increasing injection current, but has a strong dependence on EOF.

Journal ArticleDOI
22 Aug 2013
TL;DR: The vertical-cavity surface-emitting laser (VCSEL) physics and the progress of technology covering the spectral band from infrared to ultraviolet is reviewed by featuring materials and fabrication technology.
Abstract: The vertical-cavity surface-emitting laser (VCSEL) is becoming a key device in high-speed optical local area networks (LANs) and even wide-area networks (WANs). This device is also enabling ultraparallel data transfer in equipment and computer systems, including storage area networks (SANs) and wide optoelectronics fields. In this paper, we will review its physics and the progress of technology covering the spectral band from infrared to ultraviolet by featuring materials and fabrication technology. Performances such as threshold, output power, polarization, modulation, and reliability are introduced. Last, we will touch on its future prospects.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the early phases of the catastrophic optical damage (COD) process in 808-nm emitting GaAs/Al 0.35Ga0.65 and found that material composition modifications as a result of early COD phase points to melting being involved in the process.
Abstract: Extremely early phases of the catastrophic optical damage (COD) process in 808-nm emitting GaAs/Al0.35Ga0.65 As high-power diode lasers are prepared by the application of short single current pulses. Typical energy entries during these pulses are on the order of 100 nJ within several 100 ns. The resulting defect pattern is investigated by high-resolution microscopy. The root of the COD is found to be located at the waveguide of the laser structure. Analysis of material composition modifications as a result of early COD phase points to melting being involved in the process. During recrystallization, an Al-rich pattern is formed that encloses a volume of a few cube micron of severely damaged material.

Journal ArticleDOI
TL;DR: In this paper, a flat OFCG based on a single commercial vertical cavity surface emitting laser under gain-switching regime with 20 optical lines (spaced by 4.2 GHz) in a 3-dB bandwidth was presented.
Abstract: Optical frequency combs generators (OFCGs) have demonstrated to be extremely useful tools in a wide variety of applications. The current research trends look toward compact devices that are able to offer high phase correlation between optical lines, and in this sense, mode-locked laser diodes (MLLDs), with repetition frequencies in the few gigahertz (GHz) range, and especially microresonators, with repetition frequencies of hundreds of GHz, are the most promising devices fulfilling these requirements. Nevertheless, focusing in the few GHz frequency rate, MLLDs cannot provide continuous tunability and require special devices that are still far from offering reliability and repeatability for commercial use. In this letter, we demonstrate for the first time the generation of a flat OFCG based on a single commercial vertical cavity surface emitting laser under gain-switching regime with 20 optical lines (spaced by 4.2 GHz) in a 3-dB bandwidth, offering wide tunability range and very high phase correlation between optical modes. This OFCG does not need any external modulator and it is the most energy-efficient OFCG reported to date.

Journal ArticleDOI
Hans Wenzel1, Paul Crump1, J. Fricke1, Peter Ressel1, Götz Erbert1 
TL;DR: In this paper, an anti-guiding layer with a high refractive index inserted at the edges of the active stripe was proposed to suppress higher-order lateral modes in planar waveguides.
Abstract: For a maximum fiber-coupled power, high power broad-area diode lasers must operate with a small lateral far-field divergence at high continuous wave (CW) powers. However, these structures are laterally multi-moded, with a low beam quality and wide emission angles. We present a new approach to suppress higher-order lateral modes based on an anti-guiding layer with a high refractive index inserted at the edges of the active stripe. Simulations of planar waveguides containing germanium layers reveal that strong mode-coupling effects occur. These are found to vary as a function of the thickness of the inserted layer. By embedding the germanium layer in the outer region of a ridge-waveguide, the mode coupling effects result in a reduction of the modal gain of higher-order lateral modes. The lateral far-field divergence of fabricated 90- μm stripe lasers emitting at 980 nm and containing such an anti-guiding layer is narrowed by 3° at a CW output power of 10 W.

Journal ArticleDOI
TL;DR: In this article, the authors reported a large inherent direct gap optical gain ≥1300 cm−1 at room temperature from both tensile-strained n+ Ge-on-Si films and intrinsic Ge-onsulator using femtosecond transmittance spectroscopy captured before direct-to-indirect valley scattering.
Abstract: The recent demonstration of Ge-on-Si diode lasers renews the interest in the unique carrier dynamics of Ge involving both direct (Γ) and indirect (L) valleys. Here, we report a large inherent direct gap optical gain ≥1300 cm−1 at room temperature from both tensile-strained n+ Ge-on-Si films and intrinsic Ge-on-insulator using femtosecond transmittance spectroscopy captured before direct-to-indirect valley scattering. This inherent direct gap gain is comparable to III-V semiconductors. For n+ Ge, this transient gain is ∼25× larger than its steady state gain, suggesting that reducing Γ→L or enhancing L→Γ intervalley scattering may significantly increase the optical gain of Ge lasers.

Journal ArticleDOI
TL;DR: The simulation of spectral stabilization of broad-area edge-emitting semiconductor diode lasers is presented and the focus of the model lies on the prediction of influences on the spectrum and power characteristics by frequency selective feedback from external optical resonators.
Abstract: The simulation of spectral stabilization of broad-area edge-emitting semiconductor diode lasers is presented in this paper. In the reported model light-, temperature- and charge carrier-distributions are solved iteratively in frequency domain for transverse slices along the semiconductor heterostructure using wide-angle finite-difference beam propagation. Depending on the operating current the laser characteristics are evaluated numerically, including near- and far-field patterns of the astigmatic laser beam, optical output power and the emission spectra, with central wavelength and spectral width. The focus of the model lies on the prediction of influences on the spectrum and power characteristics by frequency selective feedback from external optical resonators. Results for the free running and the spectrally stabilized diode are presented.

Journal ArticleDOI
TL;DR: Through experimental observations and numerical simulations, it is found that the effective gain of the different modes is the key parameter which has to be balanced in order to achieve multiwavelength emission.
Abstract: We report on an integrated approach to obtain multiwavelength emission from semiconductor ring lasers with filtered optical feedback. The filtered feedback is realized on-chip employing two arrayed-waveguide gratings to split/recombine light into different wavelength channels. Through experimental observations and numerical simulations, we find that the effective gain of the different modes is the key parameter which has to be balanced in order to achieve multiwavelength emission. This can be achieved by tuning the injection current in each amplifier.

Journal ArticleDOI
TL;DR: In this paper, the authors theoretically investigate the stability of a single-mode semiconductor laser with weak optical feedback in the short external-delay regime, and they predict complete insensitivity for these oscillations when the product of oscillation frequency and external delay time equals a small integer.
Abstract: We theoretically investigate the stability of a single-mode semiconductor laser with weak optical feedback in the short external-delay regime. Although the laser is, in general, very sensitive to feedback-induced excitation of relaxation oscillations, we predict complete insensitivity for these oscillations when the product of oscillation frequency and external-delay time equals a small integer. This may form the basis for relaxation-oscillation-free laser design.

Journal ArticleDOI
Simin Li1, Ruoming Li1, Lianyan Li1, Rui Liu1, Liang Gao1, Xiangfei Chen1 
TL;DR: In this paper, a dual-wavelength semiconductor laser is proposed and experimentally demonstrated, which is established by the grating structure consisting of two asymmetric phase shifts, which are distributed along the phase-arranging regions in the sampling pattern.
Abstract: A novel dual wavelength semiconductor laser is proposed and experimentally demonstrated. Stable dual wavelength lasing is established by the grating structure consisting of two asymmetric phase-shifts, which are distributed along the phase-arranging regions in the sampling pattern. The wavelength spacing between the two modes is about 0.51 nm at room temperature. A microwave signal at about 64 GHz can be generated by beating the two wavelengths. Based on the reconstruction-equivalent-chirp technique, the laser is fabricated by a low-cost manufacturing method.

Journal ArticleDOI
TL;DR: In this paper, the authors present a semi-analytic study of the nonlinear dynamics of reflective semiconductor optical amplifiers (RSOAs), based on the derivation of a reduced model that gives the input-output RSOA transmission function as the solution of a standard differential equation.
Abstract: Reflective semiconductor optical amplifiers (RSOAs) became a key-technology for the implementation of next generation local area passive optical networks (PONs). In this letter, we present a semi-analytic study of their nonlinear dynamics, based on the derivation of a reduced model that gives the input-output RSOA transmission function as the solution of a standard differential equation. The reduced model is computationally more efficient than full-scale computer simulations of time-domain models, and can be used for a fully analytic study of four wave mixing in the context of WDM- and OFDM-based PONs.

Journal ArticleDOI
TL;DR: In this paper, a spectrally efficient multiheterodyne scheme is applied for the independent measurement of the spectral phase profiles of three distinct semiconductor frequency combs, and the amount of quadratic and cubic phase is quantified for each source, providing insight on the dispersive properties of the semiconductor gain and the fiberized laser cavity.
Abstract: A spectrally efficient multiheterodyne scheme is applied for the independent measurement of the spectral phase profiles of three distinct semiconductor frequency combs. The amount of quadratic and cubic phase is quantified for each source, providing insight on the dispersive properties of the semiconductor gain and the fiberized laser cavity. This information is vital for the optimization and expansion of the spectral bandwidth of such sources.

Journal ArticleDOI
TL;DR: In this article, the authors compared the influence of lateral geometric design on amplifier performance by using devices with super large optical waveguide (4.8 μm) and relative low confinement factor (Γ = 1%).
Abstract: High power, high beam quality and narrow, stable spectra are achieved simultaneously using a truncated-tapered optical amplifier in a master-oscillator power amplifier-system. We compare the influence of lateral geometric design on amplifier performance, by using devices with super large optical waveguide (4.8 μm) and relative low confinement factor (Γ = 1%) . We find that the use of an amplifier with a larger active region results in both high power and high beam quality. An abandonment of cavity spoiling grooves leads to strongly improved beam characteristics.

Journal ArticleDOI
TL;DR: In this article, the authors used a semiconductor optical Bloch equation approach combined with a traveling wave equation for the electric field to explore the effect of noise on the signal quality of a quantum-dot (QD) optical amplifier.
Abstract: We use a semiconductor optical Bloch equation approach combined with a traveling wave equation for the electric field to explore the effect of noise on the signal quality of a quantum-dot(QD) semiconductor optical amplifier. Using a stochastic white noise source for the spontaneous emission inside the QDs, we can show that there is a tradeoff between amplification performance and signal quality. Nevertheless, optimized operation conditions exist and are discussed for various input signals.

Journal ArticleDOI
TL;DR: In this article, the authors investigate the nonlinear behavior of a dual-beam optically injected semiconductor laser and experimentally investigate the dynamics scenarios and their transition routes by injecting a slave laser with beams from two master lasers under different injection strengths and detuning frequencies.
Abstract: Dual-beam optically injected semiconductor lasers have been utilized in the field of microwave photonics for generations of microwave signals. To better understand the nonlinear behavior of a dual-beam optically injected semiconductor laser, we experimentally investigate the dynamics scenarios and their transition routes. By injecting a slave laser with beams from two master lasers, mappings of the dynamics scenarios including PP, PS, SP, SS, S' S', S' L, LS', and LL are plotted under different injection strengths and detuning frequencies. These scenarios are defined and differentiated by whether the dynamics and the characteristic frequencies originated from the single-beam injection scheme are being preserved (P), shifted (S), or suppressed (S') after both beams are simultaneously injected. The letter L is used if the slave laser is already injection-locked by one of the beams under the single-beam injection condition. The transition routes among these dynamics scenarios are shown to be clearly traceable by tracking and comparing the oscillation frequencies of the slave laser under the dual-beam and single-beam injections. Moreover, frequency-locking states are observed experimentally the first time in a dual-beam optically injected semiconductor laser, which occur when the frequency pushing effects from the two injected beams with opposite detunings balance each other off.

Journal ArticleDOI
TL;DR: In this article, the authors describe the development and testing of optically pumped semiconductor lasers operating at fundamental wavelengths of 1119 and 1178 nm, and demonstrate continuously tunable, single-frequency lasers with watt-level average power at 1119, 1178, and 589 nm.
Abstract: Optically pumped semiconductor lasers in conjunction with intra-cavity frequency conversion and tuning elements offer high continuous-wave power, narrow linewidth, and broad tunability. As a result, they are well suited to precision spectroscopic applications. We describe the development and testing of optically pumped semiconductor lasers operating at fundamental wavelengths of 1119 and 1178 nm. The fourth and second harmonic wavelengths are resonant with transitions in Mg II and Na I, respectively. We demonstrate continuously tunable, single-frequency lasers with watt-level average power at 1119, 1178, and 589 nm.

Journal ArticleDOI
TL;DR: In this article, the authors experimentally and numerically study the dynamics of semiconductor ring lasers that are subjected to long delay and moderate self-feedback, and study the appearance and parameter dependence of low frequency fluctuations in these systems.
Abstract: In this paper, we experimentally and numerically study the dynamics of semiconductor ring lasers that are subjected to long delay and moderate self-feedback. Through varying the pump current or the feedback strength or both, we study the appearance and parameter dependence of low frequency fluctuations in these systems. In particular, we observe different routes to the building up of the initial power amplitude.

Journal ArticleDOI
TL;DR: In this article, two different methods for all-optical inversion using dual-polarized optical injection are considered, one for single-mode vertical-cavity surface-emitting laser (VCSEL) and the other for two-mode VCSEL with a CW parallel (orthogonally) polarized beam.
Abstract: All-optical inversion in single-mode vertical-cavity surface-emitting lasers (VCSELs) under single- and dual-polarized optical injection is numerically analyzed. For single optical injection, turn-on delay of the parallel polarized power and spikes of the orthogonally polarized power are similar to those found when gain-switching a multimode semiconductor laser. We consider two different methods for all-optical inversion using dual-polarized optical injection. In the first (second) method, pulses of orthogonally (parallel) polarized light and a CW parallel (orthogonally) polarized beam are injected into the VCSEL. Similar switching times and extinction ratios are obtained with both methods. Faster operation with any of these two methods is obtained than for single injection. We show that both types of dual optical injection produce all-optical inversion and all-optical gating with similar characteristics. All-optical gating and inversion are achieved for a 2.5 Gb/s NRZ signal.