Influence of spin-dependent carrier dynamics on the properties of a dual-frequency vertical-external-cavity surface-emitting laser

Abstract

The properties of a dual-frequency vertical external cavity surface emitting laser (VECSEL), in which two linear orthogonal polarization modes are oscillating simultaneously, are theoretically investigated. We derive a model based on the ideas introduced by San Miguel et al. [San Miguel, Feng, and Moloney, Phys. Rev. A 52, 1728 (1995)], taking into account the spin dynamics of the carriers inside the quantum well (QW) based gain medium of the dual-frequency VECSEL. This model is shown to succeed in describing quite a few properties of the dual-frequency VECSEL, such as the behavior of nonlinear coupling strength between the modes, the spectral behavior of intensity noises of the modes, and also the correlation between these intensity noises. A good agreement is found with experimental data. The variables associated with the spin dependent carrier dynamics can be adiabatically eliminated due to the class-A dynamical behavior of the considered laser which is based on a cm-long external cavity. This leads to a simple analytical description of the dynamics of the dual-frequency VECSEL providing a better understanding of the physics involved.

Intensity- and phase-noise correlations in a dual-frequency vertical-external-cavity surface-emitting laser operating at telecom wavelength

“…We indeed know from Ref. [15] that this simpler model is good enough to explain the noise properties of the DF-VECSEL and can be derived from the spin-flip model.…”

“…(9-12) around the steady-state solutions (14)(15)(16)(17). After simplification, we obtain the following expression relating the photon number fluctuations [ δF x (f ), δF y (f )] of the two laser modes to the two pump fluctuations [ δN 0x (f ), δN 0y (f )]:…”

“…This partial spatial separation is required in order to make the simultaneous dual-mode operation robust. The DF-VECSEL can be modeled using a more rigorous approach by taking into account the spin-dependent dynamics of the carriers inside the active medium [15]. But, here, we follow the approach of Refs.…”

Noise Investigation of a Dual-Frequency VECSEL for Application to Cesium Clocks

“…VECSEL structures [20], [21]. This simple model was shown to derive from a more complete theory taking spin-flipping effects into account [22]. In this approach, the two modes were supposed to be exactly symmetric in terms of gain and losses, allowing to expand all noises in terms of in-phase and antiphase noise modes.…”

VSPIN: a new model relying on the vectorial description of the laser field for predicting the polarization dynamics of spin-injected V(e)CSELs

“…Nevertheless, it is shown that excessive residual linear anisotropies can fix the polarization eigenstates to linear polarizations [14][15][16][17], preventing any visible effect of spin injection especially when the spin coherence is barely maintained. Several models based on rate equations and including spin dependent carrier dynamics have already been developed for VCSELs in order to describe the evolution of the polarization eigenstates with different degrees of accuracy [18][19][20][21]. However, these models mainly consider carriers' dynamics in the active medium taking into account microscopic parameters or assume that the laser polarization state is similar to that provided by the gain structure.…”