Crafted Pulses for the Uniform Suppression of a Region in a Coherent Spectrum

We have theoretically derived and experimentally demonstrated "narrow reject" pulses which give a uniform π2 excitation off resonance, and zero excitation in a sharp hole directly on resonance. They are also insensitive to relaxation effects. This shape is symmetric and has only amplitude modulation, and so it can be implemented on most commercial NMR spectrometers or with laser modulators. It can replace conventional broadband π2 pulses in most NMR or laser pulse sequences, in order to give solvent suppression or measure spectral diffusion.