Trapped ions are a well-studied and promising system for the realization of a scalable quantum computer. Faster quantum gates would greatly improve the applicability of such a system and allow for greater flexibility in the number of calculation steps. In this talk I present experiments with a pulsed laser system, delivering picosecond pulses at a repetition rate of 5 GHz and resonant to the S1/2 - P3/2 transition in Ca+ for coherent population transfer to implement fast phase gate operations. The optical pulse train is derived from a mode-locked,
stabilized optical frequency comb and inherits its frequency stability. Using a single trapped ion, we implement different techniques for measuring the ion-laser coupling strength and characterizing the pulse train emitted by the laser, and show how all requirements can be met for an implementation of a fast phase gate operation.