Empirical study of the group delay dispersion achievable with multilayer mirrors

V Pervak,Yu A Pervak,V Fedorov,M Trubetskov

doi:10.1364/oe.21.018311

Abstract

With the help of the most advanced algorithms we obtained many dozens of multilayer dispersive mirror designs to empirically find limits for the maximum achievable negative value of the group delay dispersion (GDD). This value depends on the total thickness of coatings and layer material combination. Nb(2)O(5)/SiO(2) and Ta(2)O(50/SiO(2) combinations are studied in detail, for combinations HfO(2)/SiO(2) and TiO(2)/SiO(2) we obtained estimations for two bandwidths. We also show that reasonable values of third-order dispersion have no significant impact on the obtained results. Current state-of-the-art technology allows to produce designs with total physical thicknesses slightly higher than 10 µm and to achieve maximum negative GDD values corresponding to this total design thickness. Designs with total physical thickness of 15 µm and 20 µm are not realized yet due to high sensitivity to deposition errors.

Highlights

During the last 20 years dispersive mirrors (DM) technology [1,2,3,4,5,6,7,8,9,10,11,12,13,14] has become very popular in femto- and atto-seconds physics [15,16]
Current state-of-the-art technology allows to produce designs with total physical thicknesses slightly higher than 10 μm and to achieve maximum negative group delay dispersion (GDD) values corresponding to this total design thickness
Our goal is to draw a limit of achievable GDD values as a function of total physical thickness of a DM and working bandwidth for different layer material pairs

Summary

Introduction

During the last 20 years dispersive mirrors (DM) technology [1,2,3,4,5,6,7,8,9,10,11,12,13,14] has become very popular in femto- and atto-seconds physics [15,16]. There is high and rapidly rising demand on the DMs possessing various spectral properties and quite often designers of ultrafast laser systems are not aware of existing limitations. The larger bandwidth is required, the smaller the mean value of GDD can be achieved [6,7,11] This fact seems to be caused by fundamental causality principle and is closely connected with phase properties of multilayers [17]. Our goal is to draw a limit of achievable GDD values as a function of total physical thickness of a DM and working bandwidth for different layer material pairs. We consider single DM only, since in many cases it is used as a basic building block of more complicated systems

Formulation of the design problem and solution approach

Other layer materials pairs and TOD influence

Current state-of-the-art in DM production

Findings

Conclusions