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Terahertz phase imaging can reveal the depth information of an optically opaque object and provide much better contrast for weak-absorption materials. We demonstrate a continuous-wave terahertz interferometric imaging method in which a far-infrared laser interferometer is used to measure the phase distribution with diffraction-limited lateral resolution and subwavelength axial resolution. An improved four-step phase-shifting algorithm is introduced to retrieve the phase map with very high accuracy and low distortion. The relative depth profiles of two transparent samples are successfully extracted by using this method. Experimental results verify that terahertz interferometric imaging in combination with the phase-shifting technique enables effective reconstruction of the phase image of the object under test.

The significant modifications to our recently constructed electron momentum spectrometer have been implemented. Compared with our previous report, the energy and the angle resolutions are significantly improved and reach ΔE = 0.45 eV, Δθ = ±0.53° and Δφ = ±0.84°, respectively. Moreover, the details of data reduction and the relation between azimuthal angle range and the sensitivity are discussed.

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The binding energy spectra and the momentum distributions of the outer valence orbitals of W(CO) 6 have been studied by using electron momentum spectroscopy as well as non-relativistic, scalar relativistic and spin-orbital relativistic DFT-B3LYP calculations. The experimental momentum profiles of the outer valence orbitals obtained with the impact energies of 1200 eV and 2400 eV were compared with various theoretical calculation results. The relativistic calculations could provide better descriptions for the experimental momentum distributions than the non-relativistic ones. Moreover, a new ordering of orbitals 10t 1u , 3t 2g, and 7eg, i.e., 10t 1u < 3t 2g <7eg <10a 1g , is established in this work.

The (e, 2e) Spectra of Argon * Vo1.14. No. 9 (1997) 660 FAN Xiao-wei(B&@), ZHOU Shwjie(H$*), ZHANG Qing-xiang(%&#), ZHANG Wen-xin(%*:%bi), PANG Wen-ning(E*cf), LA1 De-shi(M ms),WE1 Jing-jing( E s S ) , ZHU Wei-bin( e#), WANG Xiao-dong( E @%), DENG Jing-kang(XPS@%), WANG Yan(€2), GAO Nai-fei(BfiX), ZHENG Yen-you( W ?i Z %)I, CHEN Xue-jun( I%%@)**

Detailed and accurate EMS measurements of complete valence region of N2 molecule using a high resolution （ΔE=08?eV，Δp≈01 a.u.） high efficiency electron momentum spectrometer have been performed. Several ionization peaks attributed to inner valence orbitals and correlation （satellite） states are resolved for the first time in the binding energy spectroscopy. By comparing the （e，2e） cross sections of valence orbitals and the correlations states，significant insights into the dominant character of the valence and correlation states of N2 are obtained. The EMS momentum distributions show that they provide a sensitive test for orbital wavefunctions from different theoretical models.