Research On The Design And Manufacture Of The Dispersion Compensation Films Used In The Femtosecond Laser System

In femtosecond laser system, dispersion compensation is a key technique to the generation of the ultrashort pulse. Among several dispersion compensation devices, dispersion compensation mirrors have become a hot research focus because of the advantage of precise compensation, wide compensation range and easy installation.Since domestic study on dispersion compensation mirrors started late and the results in mirror design, especially in mirror manufacture and application were not enough, we made some research on the manufacture and application of the dispersion compensation mirror in this paper.1. A Gires-Tournois (GT) mirror was designed according to the requirement of dispersion compensation in the Ti-Sapphire femtosecond laser system. Ion assisted deposition technique was adopted to manufacture this mirror. The home-made white light interferometry system was employed to test the reflection group delay dispersion (GDD) The GT mirror was applied in the Ti-Sapphire femtosecond laser system and a good clamping result was obtained. Finally a 29fs ultra-short pulse was acquired.2. A high-dispersive mirror (HDM) with an average GDD of-1500 fs2 was designed according to the requirement of dispersion compensation in the Yb-doped photonic crystal fiber laser system. It was fabricated with the ion-assisted electron-beam evaporation (IAD) technique. The HDM was used in the intracavity dispersion compensation and mode-locked soliton pulse with a 506fs duration was recorded. The extracavity pulse compression test showed that the HDM had identical pulse compression capability as the conventional grating pairs but greatly reduced the energy loss. Our results demonstrated that the HDM could be an ideal alternative to replace the dispersive compensating grating pairs.3. Tested the technology parameters of the home-built ion beam sputtered system to make it meet the requirement of manufacture and summarized a way of combining the time control and quartz crystal monitor to manufacture the dispersion compensation mirrors. The group delay dispersion curve met the design well after being tested by home-made white light interferometry system.