Tunable Oscillations in Optically Injected Semiconductor Lasers With Reduced Sensitivity to Perturbations

Abstract

Narrow linewidth optical injection into a semiconductor laser can induce periodic oscillations in the injected laser's output power with a frequency that is widely tunable by simply varying the steady-state bias current and operating temperature. Recently, it has been demonstrated that this oscillation frequency can be made nearly insensitive to small-signal fluctuations of these two parameters at certain operating points [1]. Here, we demonstrate that this insensitivity arises from multiwave mixing and interference that minimizes the response of both the gain medium and the circulating optical power at the oscillation frequency. Both experimental measurements and model calculations of optical spectra show that at the operating points of reduced oscillation frequency sensitivity, all strong components of the optical spectrum still exhibit a response to the perturbations. However, in the power spectra and the (calculated) carrier-density spectra, the response is strongly attenuated. Novel operating points that limit the sensitivity of the laser power oscillation frequency to perturbations offer the promise for improved operation of tunable photonic oscillators for radio-and microwave-frequency applications.

Radically tunable ultrafast photonic oscillators via differential pumping

“…In this context, Optically Injected Lasers (OIL) corresponding to a one-way coupling in a master-slave configuration [ Fig. 1(a)] have been shown to support relatively tunable limit cycles [12][13][14][15]; however, the need for a bulky optical isolator prevents their on-chip integration [9] and significantly restricts their applications. The utilization of strong mutual coupling, corresponding to complicated configurations where a single electric field mode is amplified by two gain blocks, has been shown to result to a gain-lever mechanism [ Fig.…”

Suppression of Intensity and Frequency Noise at Low-Sensitivity Operating Points of Period-One Dynamics of Optically Injected Semiconductor Lasers

“…However, the modulation sidebands around the strong frequency components of the optical spectrum do not show simultaneous suppression in the modulation sideband responses at the various LS operating points. This suggests that the insensitivity arises from interference of the many frequency components in the optical spectrum suppressing the response of the gain medium and circulating optical field to the fluctuating parameter at an LS operating point [28].…”

“…Recently, P1 oscillations with low-sensitivity to intrinsic and extrinsic perturbations on the laser have been identified [25]- [28]. By properly choosing the operating conditions, the nonlinear effects are exploited to mitigate the perturbation-induced noise in the system.…”

Frequency-stabilized limit-cycle dynamics of an optically injected semiconductor laser

“…Excellent qualitative and quantitative agreement between the model predictions and the experimental results in producing the nonlinear dynamics induced by optical injection has been thoroughly demonstrated. 16,20 The stability of the P1 frequency at an LS f point with respect to detuning-frequency fluctuations and the disturbances from spontaneous emission noise on the laser frequency and phase can be demonstrated by applying frequency modulation to the master laser output. A weak frequency modulation at f f ¼ 500 MHz on the master laser output simulates a fluctuation of 500 MHz in f, which can be caused by a fluctuation in the temperature or bias current of the master and/or slave lasers in the optical injection system.…”

“…20 Each of the responses of the modulation sidebands of the power spectrum shown in Figs. 2, 3, and 4 is a sum of the modulation-sideband responses of the spectral components in the optical spectrum.…”