All-optical pulse generation based on gain-induced four-wave mixing in a semiconductor optical amplifier

Abstract

A simple all-optical pulse generation technique based on gain-induced four-wave mixing in a semiconductor optical amplifier is introduced. The introduced concept is theoretically investigated and experimentally demonstrated. For a concept demonstration, 10 GHz and 42.5 GHz pulse trains are generated. A 20 nm central wavelength tunability is achieved.

Injection locking for stable all-optical pulse generation via gain-induced FWM

“…The stabilized microwave signal is then used for pulse generation through a highly nonlinear fiber [7]. Thus, the operating wavelength is limited to the tunability of the injection locking source laser.Recently, optical pulse-trains that are generated in an all-optical setting based on gain-induced FWM in an SOA have been demonstrated [9]. A unique advantage of this versatile approach is that it allows optical control of the repetition rate, which could be tuned by controlling the frequency difference between the two laser sources.…”

“…Recently, optical pulse-trains that are generated in an all-optical setting based on gain-induced FWM in an SOA have been demonstrated [9]. A unique advantage of this versatile approach is that it allows optical control of the repetition rate, which could be tuned by controlling the frequency difference between the two laser sources.…”

“…Moreover, the uncorrelated phase will also cause intensity fluctuations in the generated pulses since the FWM process is highly dependent on the phase profile of the two laser sources. In this work, we drastically improve upon this recent work [9] by using injection locking. Robust and low-phase noise pulse generation ranging from 230 MHz to ∼76 GHz with a linewidth of ∼1 Hz is experimentally demonstrated.…”

“…Once locking is achieved, the injection-locked beating signal is then injected into the fiber ring laser to generate the pulse by gain-induced FWM [9]. The linewidth of the generated pulse is also characterized and shown in Fig.…”

“…2(b). This reduced noise is highly desirable for certain applications, which utilize injection-locking such as optical arbitrary waveform generation [10], and is a direct consequence of combing the injection-locking and gain-induced FWM pulse generation techniques [9].…”