Narrow-linewidth single-frequency photonic microwave generation in optically injected semiconductor lasers with filtered optical feedback

Abstract

A narrow-linewidth single-frequency photonic-microwave-generation scheme using an optically injected semiconductor laser with a filtered optical feedback has been proposed. The filtered feedback comes from a single feedback loop, which includes a narrow bandpass filter. With the filtered feedback, the linewidth of the generated microwave can be significantly reduced from 22.4 MHz to 9.0 kHz, with the side peaks suppression of 28 dB. The proposed scheme shows superior performance compared to the conventional single-feedback configuration in terms of linewidth reduction and side peaks suppression. The proposed scheme also achieves better results compared to the complex dual-feedback setting. The mechanism for a better performance of filtered optical feedback is that the filtered feedback can effectively limit the external cavity modes and stabilize the period-one dynamics. In addition, the microwave linewidth decreases with the increase of the filter width until the optimized filter width is reached. Furthermore, the linewidth reduction and the side peaks suppression of a photonic microwave using filtered optical feedback is relatively insensitive to the frequency detuning between the filter center frequency and the free-running frequency of the semiconductor laser.

Numerical investigation on photonic microwave generation by a sole excited-state emitting quantum dot laser with optical injection and optical feedback*

“…7. It can be seen from the figure that the employing of optical feedback can generate the ECMs close to the microwave frequency f , [39] and the mode interval is approximately equal to 1/τ. As the τ increases, the ECMs will become denser.…”

“…4(a2), (b2), and (c2), some strong sidebands can be observed around the microwave frequency f , which are attributed to the external cavity modes (ECMs) excited by the external optical feedback. [12,14,39] The frequency interval between two adjacent sidebands is about 416.7 MHz, which is approximately equal to the reciprocal of the feedback time τ (= 2.4 ns). In the following discussion, the effect of feedback parameters on the microwave linewidth is studied systematically.…”

Machine learning algorithms for predicting the amplitude of chaotic laser pulses

“…For example, under stable emission, the laser emits light at the injected wavelength (the so-called injection-locking region) and has a high resonance frequency and a large modulation bandwidth, 3 which have broad applications for optical communications. The regular pulsing regime can be used for microwave generation, 4,5 while the broadband chaotic signal can be exploited for ultrafast random number generation. 6 In turn, the output of the laser in the chaotic regime can be used for testing new methods for data analysis, and in particular, for time series prediction.…”

Comparing the dynamics of periodically forced lasers and neurons

“…The nonlinear dynamics of semiconductor lasers with optical feedback has been intensively investigated [1,2], not only because of its interest as an experimental test bed to study nonlinear phenomena, but also, because it has found many practical applications [3], including random number generation [4][5][6][7], photonic microwave generation [8][9][10], chaotic lidar [11], compressive sensing [12] to name just a few. Recent experimental and theoretical studies have demonstrated that the high-dimensional feedback-induced dynamics can be exploited for neuromorphic computing, using the reservoir computing paradigm [13][14][15][16].…”