Few-Cycle Pulses Directly from a Laser

Abstract

Advances in ultrashort-pulse laser technology have led to the generation of few-cycle optical pulses directly from oscillators at high repetition rates, in contrast to external compression schemes. In this chapter, we review the technique of mode locking to obtain few-cycle pulses and describe the major developments leading to sub-two-cycle pulse generation from a Ti:sapphire laser. The master equation approach is used in a consistent way to analyze the nonlinear dynamics of such a laser as well as the noise and tuning properties of its frequency mode comb. Control over the mode combs of a few-cycle Ti:sapphire laser and a Cr:forsterite laser enables their coherent superposition in a long-term stable arrangement. An approach toward synthesizing single-cycle pulses using this technique is presented.