Experimental investigation of pulse generation with one-pump fiber optical parametric amplification

Abstract

In a recent study, the theory of pulse generation with fiber optical parametric amplification using sinusoidal (clock) intensity modulated pump was revisited. This work showed that the pulses generated through such parametric interaction exhibit a shape which depends on the signal detuning with respect to the pump position (i.e. linear phase mismatch). A near Gaussian shape can only be achieved over a small region of the gain spectrum, close to the maximum gain location. Towards the extremities of the gain spectrum, the generated pulses take a near Sinc shape which can have many potential applications such as for all-optical Nyquist limited transmitters and/or receivers. In this paper we experimentally verify the theory at repetition rates up to 40 GHz. We also discuss the impact of noise, pump saturation and walk-off on the generated pulses.

Wideband generation of pulses in dual-pump optical parametric amplifier: theory and experiment

“…The setup was limited by the 50 GHz electrical bandwidth of the C + L oscilloscope and could easily be extended to higher repetition rate. Note that pulse generation based on single-pump FOPA has been shown at repetition rates up to 40 GHz [14,19]. The good agreement between theoretical and experimental results shows that the impact of walk-off between the interacting waves is negligible.…”

“…(1)- (3), the duty cycle (DC = T FWHM × f R ) of generated pulses as a function of Δβ/γP 0 can be numerically calculated. Note that this is justified as long as the pumps modulation frequency f R is negligible compared to Δω p [14]. The results are depicted in Fig.…”

Near-Nyquist optical pulse generation with fiber optical parametric amplification

“…Because the Kerr process on which FWM is based has a quasi-instantaneous response, the generated idler at the fiber output has a pulse shape that is compressed compared to the pump. The pulse width depends on the linear phase mismatch Δβ L between the pump, idler and signal waves [6,7]. In particular, when:…”

“…In recent works [6,7], it was shown theoretically and experimentally that it is possible to achieve approximate sinc shaped pulses using fiber optical parametric amplifiers (FOPAs) in a cavity-free configuration. Indeed, an intensity-modulated pump coupled with a CW seed (signal) inside a highly nonlinear fiber (HNLF) will generate an idler wave which envelope is compressed compared to that of the pump.…”

Bandwidth and repetition rate programmable Nyquist sinc-shaped pulse train source based on intensity modulators and four-wave mixing

“…In this scheme, the ultra-short Nyquist pulses are generated all-optically and time multiplexed with no intersymbol interference (ISI), taking advantage of the orthogonality of Nyquist pulses. Various techniques to generate optical Nyquist pulses have been demonstrated including spectral reshaping of mode-locked laser [2] or fiber optical parametric amplification using one degenerated pump [3] or two dissimilar frequency pumps in order to achieve uniform pulse generation over a wide bandwidth [4]. These techniques allow for the generation of Nyquist pulses of a few picoseconds duration down to sub-picosecond.…”