  We tailor the shape and phase of the pump pulse spectrum in order to study
the coherent lattice dynamics in tellurium. Employing the coherent control via
splitting the pump pulse into a two-pulse sequence, we show that the
oscillations due to A1 coherent phonons can be cancelled but not enhanced as
compared to single pulse excitation. We further demonstrate that a decisive
factor for the coherent phonon generation is the bandwidth of the pulse
spectrum and not the steepness of the pulse envelope. We also observe that the
coherent amplitude for long pump pulses decreases exponentially independent of
the shape of the pulse spectrum. Finally, by varying the pulse chirp, we show
that the coherent amplitude is independent of while the oscillation lifetime is
dependent on the chirp sign.
