Stable harmonic modelocked laser operation by damping the temporal displacement of optical pulses in analogy to Brownian particles

Abstract

Since the first report of modelocking in 1964, every parameter of a typical oscillator has been improved by several orders of magnitude. The exception is the repetiton rate, which is still roughly in the order of the initial 56 MHz. Some applications, such as ablation-cooled material processing, require high pulse repetition rates. Harmonic modelocking presents itself as a solution. However, it has had a limited impact outside the laser research laboratory to date, but its utility can be improved significantly if its reliable, repeatable, and stable operation can be ensured.