Method for reduction of recovery time of SESAM absorbers

摘要

The present invention relates to a method for reduction of a recovery time of SESAM absorbers, especially near-surface absorbers, manufactured from semiconductor heterostructure and used for generation of ultra-short pulses by passively modelocked lasers.;In this method, on a free surface of an absorber structure with an optical resonant cavity of a thickness of an even multiple of a wave optical path, an appropriate dielectric antireflective layer is deposited. This dielectric layer consists of at least one dielectric material: SiO2 SiNx. This dielectric layer is such that a surface states density at an interface between the GaAs semiconductor and the dielectric layer is in the range of 1x1012-1x1013 cm-2eV-1. The thickness of the deposited layer is equal to a quarter of an optical wave length (λ/4) in said dielectric layer and the deposition being performed at a temperature lower than 350°C.