This paper proposes a new method that reconstructs the information of specimen by using random phase shift step in digital holographic microscopy (DHM). The principles of the method are described and discussed in detail. In practical experiment, because the phase shifter is neither perfectly linear nor calibrated, digital holograms with inaccurate phase shift step are recorded by the charge-coupled device (CCD). The phase could be accurately reconstructed from the recorded digital holograms by using the random phase-shifting algorithm, which makes up for reconstructed phase error caused by ordinary phase-shifting algorithm. The phase aberration compensation is also discussed. In order to verify the flexibility of the proposed method, numerical simulation of random phase-shifting DHM was carried out. The simulation results illustrated that the presented method is effective when the phase shift step is unknown or random in DHM.
HuiMin Xie ZhenXing Hu FuLong Dai YanJie Li PengWan Chen QingMing ZhangFengLei Huang
The cross-section profiles of polymer deformation in the hot embossing lithography process were studied by finite element method for various temperature,time and pressure.In order to successfully fabricate high-frequency grating lines,an optimal imprint condition was selected and the related experiments were carried out.The fabricated gratings were illuminated by the SEM image and AFM analysis,which agree well with the simulated results.Therefore,the finite element methods are helpful for a better comprehension of the polymer flow phenomena governing the pattern definition and the design of optimum processing conditions for successful grating fabrication.
