Research On Optical Arbitrary Waveform Generation And Application Based On Spectral Shaping

With the application of optical pulses in different fields,ultra short pulses are required to generate specific shapes.Arbitrary waveform generation technology can generate arbitrary pulses user defined by changing the parameters of optical pulses,and has attracted wide attention from scholars at home and abroad.In this paper,the waveform generation structure based on Fourier transform and frequency-to-time mapping is proposed,respectively.Different shapes of optical pulses are obtained experimentally.The main work of this article includes the following:(1)Theoretical and experimental research on waveform generation based on Fourier transform principle.The influence of the parameters such as spectral line amplitude and phase on the waveform is simulated and analyzed,and the waveforms with different shapes and different repetition rates are obtained.In the experiment,the time-domain waveforms with different pulse intervals are obtained by setting different frequency intervals and controlling? phase of the filter,respectively.And the optical pulses with different time delays are realized by controlling the phase.(2)Experimental research on waveform generation based on amplitude filtering and frequency-to-time mapping.Using the single mode fiber as the dispersive medium,different shape waveforms,such as rectangular pulse and triangular pulse waveform,and adjustable pulse width waveform are obtained experimentally.The actual length of the single mode fiber is measured from the time domain pulse width.And the number of symbols,the bit rate and the duty ratio of the code are realized in the production of the code pattern.The NRZ code and RZ code with adjustable duty ratio are obtained,respectively.The NRZ code with a bit rate of 29.41Gb/s is obtained,with a symbol rate of 13.51 Gb/s and duty ratio of 1/2 RZ code.(3)Experimental research on waveform generation based on complex filtering.The spectral shaping and frequency-to-time mapping can be realized simultaneously by complex filter,and the waveform generation structure based on amplitude filtering and frequency time mapping is simplified.The influence of the width of the spectrum and the second-order phase on the pulse width of the output waveform is analyzed.The pulse width of the output waveform changes linearly with the spectrum width or the second-order phase,and the multi pulse with adjustable pulse interval and pulse width can be obtained in the experiment.The experimental structure is simple and can realize the continuous change of dispersion.