Optical information processing and waveform shaping with femtosecond pulses

The field of femtosecond pulse shaping, in which Fourier synthesis methods are used to generate nearly arbitrarily shaped ultrafast optical waveforms according to user specification, will be reviewed [1]. An emphasis is placed on programmable Fourier transform pulse shaping methods based on the use of spatial light modulators. After the fundamental principles of pulse shaping are outlined, examples of pulse shaping using several different types of spatial light modulators will be described. Applications of pulse shaping will be illustrated by drawing on experimental results in fields ranging from quantum control to optical communications. Finally, some new research directions in pulse shaping and in ultrafast optical signal processing will be described. One example is the direct space-to-fime (DST) pulse shaper, in which the generated output waveform is a directly scaled version of the input spatial beam profile [2]. The DST pulse shaper is well suited to generation of ultrafast optical data packets for OTDM and in addition to its bulk optics implementation, may also be implemented in part using modified arrayed waveguide grating technology [3]. As a second example, I illustrate nonlinear extensions of pulse shaping known as spectral holography and spectral nonlinear optics. These techniques make possible storage, recall, correlation, and time-to-space conversion of femtosecond optical signals [4].