Computational coherent imaging based on rotational phase modulation by a cylindrical lens

Author(s):  
Yong Geng ◽  
Jiubin Tan ◽  
Zhengjun Liu
2018 ◽  
Vol 8 (7) ◽  
pp. 1146 ◽  
Author(s):  
Huaying Wang ◽  
Zhao Dong ◽  
Feng Fan ◽  
Yunpeng Feng ◽  
Yuli Lou ◽  
...  

Although digital holography is used widely at present, the information contained in the digital hologram is still underutilized. For example, the phase values of the Fourier spectra of the hologram are seldom used directly. In this paper, we take full advantage of them for characterizing the phase modulation of a spatial light modulator (SLM). Incident plane light beam is divided into two beams, one of which passes the SLM and interferes with the other one. If an image with a single grey scale loads on the SLM, theoretical analysis proves that the phase of the Fourier spectra of the obtained hologram contains the added phase and a constant part relative to the optical distance. By subtracting the phase for the image with the grey scale of 0 from that for the image with other grey scales, the phase modulation can be characterized. Simulative and experimental results validate that the method is effective. The SLM after characterization is successfully used for coherent imaging, which reconfirms that this method is exact in practice. When compared to the traditional method, the new method is much faster and more convenient.


2018 ◽  
Vol 26 (17) ◽  
pp. 22110 ◽  
Author(s):  
Yong Geng ◽  
Jiubin Tan ◽  
Cheng Guo ◽  
Cheng Shen ◽  
Weiqiang Ding ◽  
...  

Author(s):  
Z.M. Wang ◽  
J.P. Zhang

High resolution electron microscopy reveals that antiphase domain boundaries in β-Ni3Nb have a hexagonal unit cell with lattice parameters ah=aβ and ch=bβ, where aβ and bβ are of the orthogonal β matrix. (See Figure 1.) Some of these boundaries can creep “upstairs” leaving an incoherent area, as shown in region P. When the stepped boundaries meet each other, they do not lose their own character. Our consideration in this work is to estimate the influnce of the natural misfit δ{(ab-aβ)/aβ≠0}. Defining the displacement field at the boundary as a phase modulation Φ(x), following the Frenkel-Kontorova model [2], we consider the boundary area to be made up of a two unit chain, the upper portion of which can move and the lower portion of the β matrix type, assumed to be fixed. (See the schematic pattern in Figure 2(a)).


2014 ◽  
Vol E97.B (10) ◽  
pp. 2102-2109
Author(s):  
Tsubasa TASHIRO ◽  
Kentaro NISHIMORI ◽  
Tsutomu MITSUI ◽  
Nobuyasu TAKEMURA

Author(s):  
Yin S Ng ◽  
William Lo ◽  
Kenneth Wilsher

Abstract We present an overview of Ruby, the latest generation of backside optical laser voltage probing (LVP) tools [1, 2]. Carrying over from the previous generation of IDS2700 systems, Ruby is capable of measuring waveforms up to 15GHz at low core voltages 0.500V and below. Several new optical capabilities are incorporated; these include a solid immersion lens (SIL) for improved imaging resolution [3] and a polarization difference probing (PDP) optical platform [4] for phase modulation detection. New developments involve Jitter Mitigation, a scheme that allows measurements of jittery signals from circuits that are internally driven by the IC’s onboard Phase Locked Loop (PLL). Additional timing features include a Hardware Phase-Locked Loop (HWPLL) scheme for improved locking of the LVP’s Mode-Locked Laser (MLL) to the tester clock as well as a clockless scheme to improve the LVP’s usefulness and user friendliness. This paper presents these new capabilities and compares these with those of the previous generation of LVP systems [5, 6].


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