Space-time analogy and its application to design schemes borrowed from Fourier optics for processing ultrafast optical signals

Abstract Square-wave pulse generation with a variable duty ratio can be realized the help of ideas Talbot array illuminators formulated for binary phase gratings. A temporal modulation continuous wave (CW) laser field propagating through group-delay-dispersion circuit fractional length P / Q results in well defined sequence square-wave-form pulses. When P = 1 pulses D is $1/2$?> 1 2 Q 4 and $1/3$?> 3 3 6. Maximum intensity doubles triples compared to CW $D 1/2$?> D = , respectively. These used return-to-zero optical fiber communication. For 1/3$?> extra features between are found originating from finite rise drop time modulation. similar effect benefit time-space analogy predicted gratings interpreted as gleams produced by imperfect edges components rectangular