Experimental and theoretical study of filtered optical feedback in a semiconductor laser (original) (raw)
Related papers
Experimental and Theoretical Study of Semiconductor Laser Dynamics Due to Filtered Optical Feedback
IEEE Journal of Selected Topics in Quantum Electronics, 2004
We report experimental results on the nonlinear dynamical response of a semiconductor laser subjected to time-delayed ( 5 ns), frequency selective, optical feedback from a Fabry-Pérot interferometer type of filter. Three regimes of interest, based on the relative value of the filter bandwidth with respect to the relevant laser parameters (relaxation oscillation frequency and external cavity mode spacing), are identified, viz. a wide filter case, an intermediate filter width case, and a narrow filter case. The dynamical response of the laser is shown to be quite different in each of these regimes. The principal results are 1) the laser's linewidth enhancement factor, coupled with the nonlinear response of the filter, can be exploited to induce nonlinear dynamics in the instantaneous optical frequency of the laser light on a time scale related to the time-delay of the feedback, 2) a mode mismatch effect which arises from a detuning between the filter center frequency and the nearest external cavity mode and manifests itself in a reduction of the maximum light available for feedback, and 3) a reduction in, or even disappearance of, relaxation oscillations in the laser dynamics when a filter of appropriate width is chosen. More generally, it is observed that certain dynamics that occur due to unfiltered optical feedback may be suppressed when the feedback light is spectrally filtered.
Dynamics of semiconductor lasers with filtered optical feedback
2006
In the filtered optical feedback (FOF) scheme a part of the emission of the laser is spectrally filtered, for example by a Fabry-Perot filter, and than fed back into the laser. If a semiconductor laser is subject to such delayed FOF qualitative different types of oscillations are possible: the well known relaxation oscillations and, more remarkably, frequency oscillations. We explain
Filtered Optical Feedback Induced Dynamics in Semiconductor Lasers
2003
A diode laser with optical feedback is a paradigm for studying nonlinear dynamics in delayed feedback systems. Filtered optical feedback (FOF), during which the spectral content of feedback light is altered by a filter, provides a mechanism for controlling the dynamical response of a laser. A filter, due to its nonlinear response function, introduces a controllable nonlinearity in the feedback system, and its influence on the laser dynamics can be manipulated via the filter?s bandwidth, and its detuning from the laser frequency. FOF offers several advantages over conventional optical feedback (COF), which we will enumerate. Most importantly, we demonstrate in this paper that one can exploit the interplay between the nonlinear response of the filter, and the a-parameter of the laser, to induce novel dynamics in the frequency of light from the laser. The origin of frequency dynamics can be qualitatively motivated by recognizing two facts; firstly, a filter alters the amplitude of the ...
Dynamical behavior of a semiconductor laser with filtered external optical feedback
IEEE Journal of Quantum Electronics, 1999
We report on a theoretical analysis of the dynamical performance of a semiconductor laser under the influence of delayed weak filtered external optical feedback. The filter widths considered range from 1 to 100 GHz. The analysis concentrates on the well-known low-frequency fluctuations (LFF's) regime, in which LFF's occur in the absence of filtering. As expected, filtering the feedback light stabilizes the system in general. LFF can already be suppressed for moderately broad filters (25-50 GHz). In that case, the system was found to operate on the maximum gain mode with a small amplitude limit cycle. We show how the filtering can, in principle, be used for targeting the laser on the maximum gain mode.
Semiconductor laser dynamics with two filtered optical feedbacks
… Conference on Fibre …, 2012
We study eperimentally and numerically the dynamics of a semiconductor laser subject to FOFs from two separate external cavities. Our results show that the inclusion of second FOF introduces rich control over the laser frequency.
Analysis of the external filtered modes of a semiconductor laser with filtered optical feedback
Semiconductor Lasers and Laser Dynamics II, 2006
We present a detailed analysis of the external filter mode (EFM) structure of a semiconductor laser subject to filtered optical feedback (FOF). These EFMs form the 'backbone' of the dynamics of the system. Specifically, from the governing delay differential equations, we find analytic, transcendental expressions for both the solution curves, which define the frequency and amplitude of the EFMs, and their envelopes. We use numerical continuation to find and follow solutions of these equations. This approach allows us to show how the structure depends on the key parameters of filter width, filter detuning, and feedback phase. In other words, we identify the external influence of the filter on an otherwise fixed laser.
Physical Review E, 2007
Filtered optical feedback (FOF) can be used to stabilize a semiconductor laser but also to generate chaotic laser emission that may find applications in chaos communication schemes. We study theoretically the dynamics the FOF laser and identify the feedback phase as an important parameter that organizes the huge degree of multi-stability in this system. A systematic experimental study of the phase effect on the dynamics is presented that is supported by theoretical findings.
Filtered optical feedback induced frequency dynamics in semiconductor lasers
Physical review letters, 2004
We demonstrate experimentally and numerically that, by spectrally filtering the delayed optical feedback into a semiconductor laser, one can elicit novel dynamics in the frequency of the laser output light on a time scale that is set by the delay time of the feedback. In particular, we show that through a judicious choice of the filter bandwidth, and its frequency relative to that of the laser, one can produce controlled oscillations in the frequency of light from the laser.
Physical Review E, 2006
We investigate the dynamics of a semiconductor laser subject to coherent, delayed filtered optical feedback. This system produces multi-stable continuous wave, relaxation and pure frequency oscillations. We show that the feedback phase is a key quantity for controlling this dynamical complexity. A systematic analysis with the feedback phase as one bifurcation parameter reveals the system's overall dynamical structure. PACS numbers: 42.65.Sf, 05.45.Xt, 02.30.Ks, 42.55.Px In a system with feedback a part of the output re-enters into the system, possibly after having been manipulated externally. Typically, the feedback mechanism involves a time delay, which is substantial in many applications; see, e.g., the recent studies Refs. . Laser systems with delayed feedback are of particular interest, because of their possible practical applications, for example, for secure communication via a chaotic carrier .