Optical pulse shaping capabilities of grating-assisted codirectional couplers

Ultrashort pulse propagation through grating-assisted codirectional couplers (GACCs) is numerically investigated. For this purpose, the linear temporal responses of uniform GACCs to ultrashort optical pulses are calculated and the influence of the different physical grating parameters (e.g. length and coupling strength) on these temporal responses is evaluated. It is observed that depending on the length and coupling strength of the uniform grating perturbation one can achieve very different temporal shapes at the output of the device, including square temporal waveforms as well as equalized multiple pulse sequences. These results open important new perspectives towards the implementation of practical, integrated optical pulse shapers operating in the picosecond and sub-picosecond regimes.