Hitachi High-tech Corporation

Nagoya University

Koh Saitoh

Makoto Kuwahara

Toru Ujihara

Nobuo Tanaka

Tsutomu Nakanishi

Yoshikazu Takeda

Hidefumi Asano

The present invention is to generate a spatially phase modulated electron wave. A laser radiating apparatus, a spatial light phase modulator, and a photocathode are provided. The photocathode has a semiconductor film having an NEA film formed on a surface thereof, and a thickness of the semiconductor film is smaller than a value obtained by multiplying a coherent relaxation time of electrons in the semiconductor film by a moving speed of the electrons in the semiconductor film. According to the configuration, a spatial distribution of phase and a spatial distribution of intensity of spatial phase modulated light are transferred to an electron wave, and the electron wave emitted from an NEA film is modulated into the spatial distribution of phase and the spatial distribution of intensity of the light. Since the spatial distribution of phase of the light can be modulated as intended by a spatial phase modulation technique for light, it is possible to generate an electron wave having a spatial distribution of phase modulated as intended.

Spatially phase-modulated electron wave generation device

A path of a spin-polarized electron beam is split into two by a splitter. A spin direction of the spin-polarized electron beam is rotated by a spin direction rotator disposed on a first path, and delayed by a first delay device. On a second path, the electron beam passes through a sample stage. The spin-polarized electron beams split into the first path and the second path are superposed by a biprism, and its intensity distribution is measured. Coherence is measured from a relation between a spin direction rotation angle, a delay time, and a visibility of an interference fringe.

Coherence measuring device for spin-polarized electron beam and method using the same

An electron microscope which utilizes a polarized electron beam and can obtain a high contrast image of a sample is provided. The microscope includes: a laser; a polarization apparatus that polarizes a laser beam into a circularly polarized laser beam; a semiconductor photocathode that is provided with a strained superlattice semiconductor layer and generates a polarized electron beam when irradiated with the circularly polarized laser beam; a transmission electron microscope that utilizes the polarized electron beam; an electron beam intensity distribution recording apparatus arranged at a face reached by the polarized electron beam that has transmitted through the sample. An electron beam intensity distribution recording apparatus records an intensity distribution before and after the polarization of the electron beam is reversed, and a difference acquisition apparatus calculates a difference therebetween.

Electron microscope

Growing community of inventors

Nagoya, Japan

Koh Saitoh