Design of broadband reflective circular polarizer for attosecond pulse in the extreme ultraviolet region

Abstract

In this paper, we present a design method of broadband reflective circular polarizer (BRCP) in the extreme ultraviolet (EUV) region. By using this method, we designed three BRCPs with a 6, 12 and 18 eV bandwidth, respectively. Then, we investigated the performances of designed BRCPs in theory. The results indicated that the reflected lights of these BRCPs all showed a nearly 100% circular polarization degree and considerable circular reflection in their design band. In addition, we also studied the origin of high circular polarization degree by analyzing the phase shift and the reflectivity ratio between s- and p-polarized lights induced by the reflection of BRCPs. Furthermore, the pulse responses of BRCPs for attosecond pulses were also investigated. The proposed EUV BRCPs can be used for controlling the polarization state of broadband EUV sources, e.g., generating the circularly polarized attosecond pulse by a linearly polarized one.

Design of reflective phase retarders in the extreme ultraviolet based on chirped Mo/Si multilayer mirrors

“…In addition, the corresponding values of P all increase with E due to the smaller absorption coefficient of Mo at larger E. In particular, for an incident light with a 90 eV photon energy, an optimized chirped mirror can realize 16.65% or 7.04% output efficiency when designed as a quarter-wave plate or a half-wave plate, respectively. When a chirped multilayer structure based quarter-wave plate is used for the polarization conversion of monochromatic EUV light with linear polarization, nearly 100% degree of circular polarization can be achieved by adjusting the azimuthal angle between the incident light and the plate to fulfill = arctan(|r p /r s |) (Tang et al, 2017), such as 17.97 for 80 eV, 20.64 for 85 eV and 24.71 for 90 eV.…”

“…In particular, an EUV phase retarder achieving 90 phase retardation (i.e. quarter-wave plate) can realize the polarization state conversion between linear polarization and the circular polarization of an EUV light source, and achieve nearly 100% degree of circular polarization by choosing a suitable azimuthal angle (Tang et al, 2017), which is widely applied in EUV magnetic circular dichroic imaging (MCD) (Chen et al, 1990) and resonant magnetic scattering (Kao et al, 1994).…”

Design of broadband reflective quarter-wave plates in the water window region based on aperiodic Cr/Sc multilayer mirrors

“…Compared with (1), (2) is easier to realize in experiments because it does not need to change the generation process of high-order harmonic of traditional linear polarization 24 . Recent research on (2) include the following: Schmidt et al 21 .…”

“…Compared with (1), ( 2) is easier to realize in experiments because it does not need to change the generation process of high-order harmonic of traditional linear polarization. 24 Recent research on (2) include the following: Schmidt et al 21 produced a transmissive quarter-wave plate based on a self-supporting multilayer structure in the UV region and applied it to the polarization state conversion of higher harmonic radiation, and Vodungbo et al 25 used four mirrors coated with 35 nm Mo and 5 nm B 4 C to obtain high-order harmonics with circular polarization in the EUV region. However, research on optical components for producing the water window attosecond pulse with circular polarization has not been reported.…”

Multiobjective optimization in design of broadband extreme ultraviolet multilayers

“…A straightforward way to increase the reflected bandwidth is to use the aperiodic multilayer, and this method have been well developed and intensively investigated in this field [4,5]. Recently, it is a routine method to develop a broadband EUV multilayer via consideration of the conventional performance of reflected profile, and much effort has been made towards to meet some other advanced requirements in multilayer design, such as the throughput of reflected bandpass, relative dispersion of reflectivity [6], effect of random thickness errors [5], polarization degree of reflected plateau [7] and so on. Unfortunately, in most of these researches, those advanced performances are test using the multilayer structure which is obtained by only optimizing the reflected profile, which is unable to optimize those advance performances.…”