Browsing by Author "Jian, Zhi-Cheng"

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4-Port polarization-independent wavelength-interleaving bidirectional circulator
(2008-01-15)
Hsieh, Po-Jen
;
Chen, Jing-Heng
;
Hsieh, Hung-Chih
;
Jian, Zhi-Cheng
;
Su, Der-Chin
This study develops an alternative type of 4-port polarization-independent wavelength-interleaving bidirectional circulator. In this circulator the even- and odd-channels circulate with opposite handedness regardless of the state of polarization of signals. It has a pair of orthogonal holographic spatial- and polarization modules (HSPMs) and a Lyot-Ohman filter (LOF). Each HSPM has two holographic spatial walk-off polarizers (HSWPs), two glass plates and two half-wave plates. The function of the HSWJP is firstly described. Next, the structures and the operating principles of the HSPM and the LOF are also described. Then, the operating principle and the performance of this circulator are discussed. It has such merits as polarization-independence, compactness, high isolation, lack of polarization mode dispersion and ease of fabrication. (c) 2007 Elsevier B.V. All rights reserved.
A method for measuring two-dimensional refractive index distribution with the total internal reflection of p-polarized light and the phase-shifting interferometry
(2006-12-01)
Jian, Zhi-Cheng
;
Hsieh, Po-Jen
;
Hsieh, Hung-Chih
;
Chen, Huei-Wen
;
Su, Der-Chin
Based on the total internal reflection of p-polarized light and the phase-shifting interferometry, an alternative method for measuring the two-dimensional refractive index distribution of a material is presented. The p-polarized light is incident on the boundary between a right-angle prism and a tested material. When the total internal reflection occurs at the boundary, and the p-polarized light has a phase variation. It depends on the refractive index of the tested material. Firstly, the two-dimensional phase variation distribution of the p-polarized light at the boundary is measured by the four-step phase shifting interferometric technique. Then, substituting the data into the special equations derived from Fresnel equations, the two-dimensional refractive index distribution of the tested material can be obtained. (c) 2006 Elsevier B.V. All rights reserved.
Nano-roughness measurements with a modified Linnik microscope and the uses of full-field heterodyne interferometry
(2008-12-01)
Chen, Yen-Liang
;
Jian, Zhi-Cheng
;
Hsieh, Hung-Chih
;
Wu, Wang-Tsung
;
Su, Der-Chin
A collimated heterodyne light enters a modified Linnik microscope, and the full-field interference signals are taken by a fast CMOS camera. The sampling intensities recorded at each pixel are fitted to derive a sinusoidal signal, and its phase can be obtained. Next, the 2-D phase unwrapping technique is applied to derive the 2-D phase distribution. Then, Ingelstam's formula is used to calculate the height distribution. Last, the height distribution is filtered with the Gaussian filter, the roughness topography and its average roughness can be obtained and its validity is demonstrated. (c) 2008 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3050357]
Optimal condition for full-field heterodyne interferometry
(2007-11-01)
Jian, Zhi-Cheng
;
Chen, Yen-Liang
;
Hsieh, Hung-Chih
;
Hsieh, Po-Jen
;
Su, Der-Chin
An area scan digital camera is used to record the full-field heterodyne interference signals, and the processes to derive the associated phases from the data of the recorded frames under a convenient condition are described. By calculating the possible errors under several different cases, an optimal condition to get better results is proposed. (c) 2007 Society of Photo-Optical Instrumentation Engineers.