High repetition-rate pulse generation for millimeter-wave pulse signal by two cascaded Gires–Tournois Interferometers

Periodic Time-Domain Modulation for the Electrically Tunable Control of Optical Pulse Train Envelope and Repetition Rate Multiplication

“…In both cases, all the output pulses have the same amplitude and shape (the same shape as in the input train). However, to modify also the envelope of the train of pulses, more complex nonintuitive filters have to be applied [15]- [20]. This prevents the use of simple phase devices such as fiber optics or LC-FBGs, requiring the use of optical filters able to process individual spectral lines and being thus limited by the available filtering resolution.…”

“…Of specific interest are techniques for pulse repetition rate multiplication (RRM), which are used to generate ultrafast optical pulse trains from a low repetition rate input pulse train [7]- [14]. In applications such as ultrahigh-speed optical communications and the optical generation of millimeter-wave waveforms, uniform multiplication of the input repetition rate is not enough, since the amplitude of each of the resulting pulses needs to be controlled individually [15]- [20].…”

“…These last two approaches require the use of bulk optics with the typical shortcomings such as significant insertion losses, limited integration capabilities with fiber or waveguide optics systems, and the need of accurate alignment and stability. Periodic filters based on planar lightwave circuits to permit the use of integrated optics have also been proposed [14], [19], [20], [22], but degradations in output pulse trains are found due to imperfections in the fabrication of the devices. Moreover, modifying the multiplication ratio or the train envelope is difficult in the integrated devices and slow in the case of the schemes based on liquid crystal modulators.…”