Coherent Synthesis of Multicolor Femtosecond Pulses

Abstract

The attosecond pulse generation is realized in XUV region by using high-order harmonics [1],[2]. The pulse duration in visible and infrared region is approaching to the monocycle limit [3]. For further pulse shortening in the visible and infrared region, the coherent addition of the different-color pulses is the candidate for the generation of the monocycle pulse. A subfemtosecond pulse train may also be generated by using Fourier synthesis of multicolor pulses [4],[5]. The schematic of Fourier synthesis is shown in Fig. 1. Fourier synthesis of multicolor pulses may generate not only attosecond pulse train but also desired shape of the electric field such as triangle or rectangle shapes. This can be called as an optical function generator. The optical phase relation of different-color pulses have to be locked in order to realize it.