On-chip optical pulse shaper for arbitrary waveform generation

We propose and demonstrate a silicon-on-insulator （SOI） on-chip optical pulse shaper based on four-tap finite impulse response. Due to different width designs in phase region of each tap, the phase differences for all taps are controlled by an external thermal source, resulting in an optical pulse shaper. We further demonstrate optical arbitrary waveform generation based on the optical pulse shaper assisted by an optical frequency comb injection. Four different optical waveforms are generated when setting the central wavelengths at 1533.78 nm and 1547.1 nm and setting the thermal source temperatures at 23 ℃ and 33 ℃, respectively. Our scheme has distinct advantages of compactness, capability for integrating with electronics since the integrated silicon waveguide is employed.

Recent progresses on optical arbitrary waveform generation

This paper reviews recent progresses on optical arbitrary waveform generation （AWG） techniques, which could be used to break the speed and bandwidth bottle- necks of electronics technologies for waveform generation. The main enabling techniques for optically generating optical and microwave waveforms are introduced and reviewed in this paper, such as wavelength-to-time mapping techniques, space-to-time mapping techniques, temporal pulse shaping （TPS） system, optoelectronics oscillator （OEO）, programmable optical filters, optical differentiator and integrator and versatile electro-optic modulation implementations. The main advantages and challenges of these optical AWG techniques are also discussed.

Cross-correlation frequency-resolved optical gating scheme based on a periodically poled lithium niobate waveguide for an optical arbitrary waveform measurement

This study proposes a novel scheme of a cross- correlation frequency-resolved optical gating （X-FROG） measurement for an optical based on the sum frequency arbitrary waveform （OAW） generation （SFG） effect of a periodically poled lithium niobate （PPLN） waveguide. Based on the SFG effect and combined with the principal component generalized projects algorithm on a matrix, the theory model of the scheme is established. Using Matlab, the proposed OAW measurement X-FROG scheme using the PPLN waveguide is simulated and studied. Simulation results show that a rectangular pulse is a suitable gate pulse because of its low errors. Moreover, the increased complexity of OAW and phase mismatch decrease measurement accuracy.

Improving the intensity and efficiency of compressed echo in rare-earth-ion-doped crystal

We investigate the intensity and efficiency of a compressed echo, which is important in arbitrary waveform generation（AWG）. A new model of compressed echo is proposed based on the optical Bloch equations, which exposes much more detailed parameters than the conventional model, such as the time delay of the chirp lasers, the nature of the rare-earth-iondoped crystal, etc. According to the novel model of compressed echo, we find that reducing the time delay of the chirp lasers and scanning the lasers around the center frequency of the inhomogeneously broadened spectrum, while utilizing a crystal with larger coherence time and excitation lifetime can improve the compressed echo＇s intensity and efficiency. The theoretical analysis is validated by numerical simulations.