Photon Factory Activity Report 2018 #36 (2019)

BL-11A/2018G129

Talbot Optics Installation on Soft X-ray Projection Microscopy
1

Tatsuo SHIINA1*, Prane Mariel Basco ONG1, Yasuhito KINJO2, and Atsushi ITO3
Graduate School of Advanced Integration Science, Chiba Univ., Chiba-shi, Chiba, 263-8522, Japan
2Tokyo Metropolitan Industrial Technol. Res. Inst., Koto-ku, Tokyo 135-0064, Japan
3School of Engineering, Tokai Univ., Hiratsuka-shi, Kanagawa, 259-1292, Japan

1 Introduction
Up to now, we have developed soft X-ray projection
microscopy system with the correction technique toimprove blurred projection images due to Fresnel
diffraction. The iteration procedure was applied tobiological samples and their successful corrections wereachieved for the soft X-rays in the range of 700eV–1keV.
To extend the application of projection microscopy, we
tried to incorporate Talbot optics into projection
microscopy to obtain phase information that cannot be
accessible by normal projection microscopy. First we
examined the coherency of soft X-ray region at BL11A.[1]In this study considering the coherency, we installed Talbot
optics into the soft X-ray projection microscopy systemand obtained preliminary results.
2 Experiment
Talbot effect is self-imaging effect to make the intensity
distribution due to the grating period at a certain distance.
Furthermore, it can extract the phase information byshifting the grating fringe with a certain phase interval. We
installed a grating and a nano-positioning stage into thecurrent soft X-ray projection microscopy system. The set
up is shown in Fig.1. The pinhole of 1µm or 2µm diameter
was utilized as an imaginary light source. The grating with
2µm or 4µm interval was put after the pinhole with thedistance determined by Talbot optics. The sample can bemoved within the distance of 4mm between the grating andthe CCD image sensor, which enables the magnification ofimages. The projection of this microscope is effective, andthe sample is magnified 40 – 76 times depending on thesample position. The grating, newly developed by Silson
Ltd, has 5mm x 5mm imaging area with the uniform height(700 µm) and width (2µm or 4µm intervals) of Au lattices.
Grating images are shown in Fig.2 with a visible lightmicroscope image and a soft X-ray (1keV) image. Nanopositioning stage produced by Sigma Tech Co., Ltd, has a
10nm feedback positioning control, and it is ideal tocontrol phase shift of the grating. Talbot effect wasadjusted by the grating interval and the distance between
the grating and the sample.
Figure 3(a) shows the observation example of slice
sample of a human hair. Sample tissue was magnified 165
times and enlarged to fit the illuminated area. The medulla,a central part of hair, was observed at the center. The soft
X-ray was 1keV and the pinhole was 1µm diameter. The
grating was shifted perpendicular to the optical axis with
0.4µm interval. The phase distribution was extracted by theanalysis of a set of grating phases shifted images. The
result is shown in Fig.3(b). The cortex and medulla havedifferent phase change.
The medulla represents

complicated structure and its lower right part and the upper
left part seem to have the different phase orientation. We
are continuing the improvement of the analysis procedure.

Fig.1 : Set up of Talbo optics into the soft X ray projection
microscopy.

(a) Optical microscope (b) Soft-X ray microscope
Fig.2 : New graing for imaging (2µm interval).

(a) Observation Image(b) Phase Image
Fig.3 : Observation of human hair slice sample.
References[1] T. Shiina et al., PF Activity Report 2017 #35 (2018).
http://pfwww.kek.jp/acr/2017pdf/u_reports/pf17b0296.pdf* shiina@faculty.chiba-u.jp