Noise-assisted binary information transmission in vertical cavity surface emitting lasers (original) (raw)

Polarization resolved intensity noise in vertical-cavity surface-emitting lasers

Physical Review A, 2001

We report explicit analytical and numerical results for the polarization resolved intensity noise of verticalcavity surface-emitting lasers operating in the fundamental transverse mode. We describe the fluctuations of the linear and circular polarization components of linearly polarized states on both sides of a nonthermal polarization switching. Our description is valid for small and large birefringence and arbitrary values of the spin flip rate, giving a complete description of the role of these parameters. Normalized cross-correlation functions for both linear and circular components are discussed in detail. They show different degrees of anticorrelated fluctuations in different frequency ranges.

Relative Intensity Noise of Vertical-Cavity Surface- Emitting Lasers Subject to Variable Polarization- Optical Feedback

Inthis paper, the influence of variable polarization angle of the optical feedback on the relative intensity noise (RIN) of a vertical-cavity surface-emitting laser (VCSEL) is experimentally investigated. VCSEL lases in two orthogonally polarized (XP and YP) modes. For the dominant polarization mode (i.e. XP) the RIN is minimum at a polarization angle of 0o , while it is a minimum at 90o for the suppressed polarization mode (YP) it is minimum at a polarization angle of 90o . Furthermore, for a high optical feedback level the RIN of the XP mode increases rapidly with the polarization angle, whereas for the YP mode the RIN is low for angles > 45°. In addition, result shows that the relaxation oscillations are damped due to the optical feedback. We also show that as the polarization angle of the optical feedback increases a number of spectral lines appear in VCSEL spectrum, thus representing the complex dynamics behavior induced by the feedback.

Relative intensity noise of vertical cavity surface emitting lasers

Applied Physics Letters, 1993

A study of the relative intensity noise (RIN) of two all semiconductor vertica1 cavity surface emitting lasers is presented. We find that the slope of the low frequency RIN agrees with theory for the fundamental mode only and that transverse modes introduce sharp changes in the RIN and put a limit on the minimum attainable RIN. For the fundamental mode, both devices achieve a RIN of less than -140 dB/Hz for optical powers less than 1 mW. This good performance is attributed to the high reflectivity of the cavity mirrors.

The influence of extra carrier noise on vertical-cavity surface-emitting laser

2004

We find experimentally that the relaxation oscillation (RO) peak in the relative intensity noise (RIN) of a semiconductor laser broadens by adding noise to the pump current. In our experiments we use a vertical-cavity surface-emitting laser. The broadening of the RIN peak with increasing carrier noise level is interpreted to be due to an increase of the non-linear gain saturation. * mcsoriano@tona.vub.ac.be roeedings ymposium siiiGviy fenelux ghpterD PHHRD qhent RW

The influence of extra carrier noise on vertical-cavity surface-emitting lasers

EQEC '05. European Quantum Electronics Conference, 2005., 2005

Quantum noise and polarization fluctuations in vertical-cavity surface-emitting lasers

Physical Review A, 1997

We investigate the polarization fluctuations caused by quantum noise in quantum well vertical cavity surface emitting lasers (VCSELs). Langevin equations are derived on the basis of a generalized rate equation model in which the influence of competing gain-loss and frequency anisotropies is included. This reveals how the anisotropies and the quantum well confinement effects shape the correlations and the magnitude of fluctuations in ellipticity and in polarization direction. According to our results all parameters used in the rate equations may be obtained experimentally from precise time resolved measurements of the intensity and polarization fluctuations in the emitted laser light. To clarify the effects of anisotropies and of quantum well confinement on the laser process in VCSELs we therefore propose time resolved measurements of the polarization fluctuations in the laser light. In particular, such measurements allow to distinguish the effects of frequency anisotropy and of gain-loss anisotropy and would provide data on the spin relaxation rate in the quantum well structure during cw operation as well as representing a new way of experimentally determinig the linewidth enhancement factor α.

Spatially dependent noise model for vertical-cavity surface-emitting lasers

Ieee Journal of Quantum Electronics, 2004

We present a comprehensive noise model for verticalcavity surface-emitting lasers (VCSELs). The time-domain model accounts for the stochastic fluctuations in the local carrier density in the separate confinement heterostructure and quantum wells, and in the modal intensity and phase of both the internal and the out-coupled optical field. In this work, we consider these fluctuations to be caused by the temporal uncertainty of the processes that supply or consume carriers and photons, such as carrier diffusion and photons escaping the cavity, and the processes that create or annihilate carriers and photons, such as stimulated emission and absorption. The noise model is based on a deterministic quasithree-dimensional dynamic model that treats the carrier transport, heat generation and dissipation, and optical fields in the device. Langevin noise terms are derived and added to the rate equations in the numerical solution. The noise model is applied to simulate the noise characteristics of fundamental-mode stabilized VCSELs with a shallow, mode discriminating, surface relief. The relative intensity noise and frequency noise of the output are calculated. From the latter, the linewidth of the VCSEL can be estimated. The results are compared with those of conventional multimode VCSELs. and is currently working toward the Ph.D. degree. His research is focused on characterizing and modeling the dynamics of vertical-cavity surface-emitting lasers.

Mode-partition noise in vertical-cavity surface-emitting lasers

IEEE Photonics Technology Letters, 1997

We present a numerical study of the effects of carrier diffusion and spatial hole-burning on the noise characteristics of vertical-cavity surface-emitting lasers (VCSEL's) under both single-mode and multimode operations. In the case of singlemode operation, VCSEL noise characteristics are similar to those of edge-emitting lasers except for a diffusion-induced damping of relaxation oscillations. Under multimode operation, VCSEL's exhibit low-frequency noise enhancement due to mode partition. However, depending on the spatial distributions of the transverse modes excited, the mode-partition noise characteristics can be quite different.

2Direct Modulation of Multimode Vertical Cavity Surface Emitting Lasers

2000

Vertical cavity surface emitting lasers are semiconductor lasers where the optical cavity is defined epitaxially, perpendicular to the surface of the wafer. This gives rise to optical and electrical properties that are quite different from the traditional edge emitting lasers that are now used in microwave photonic links. This work is an investigation into the suitability of using multimode VCSELs for such links which require high fidelity analog signal transmission. Experimental measurements were made and theoretical and numerical models of multimode VCSELs were developed to gain a deeper understanding of the physics limiting their performance. In particular, spatial inhomogeneities in the optical mode and active region along with multiple transverse mode coupling were studied to determine their effects on the noise and dynamic modulation properties of these lasers.

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