Phase space retrieval and the imaging system effect
Phase space optics allows the four dimensional (4D) simultaneous visualization of both space (x) and spatial frequency (u) information. The Wigner distribution function (WDF) is commonly used to represent the phase space characterization. Compared with the coherent optical field expressed by two dimensional (2D) complex amplitude, the 4D WDF (2D space and 2D spatial frequency) can characterize optical field with arbitrary coherent state. It is especially advantageous for the characterization of partially coherent optical fields. The WDF is real and may have negative values, which are the result of phase space interference. In this paper, an improved phase space retrieval method is demonstrated. First, capture three dimensional intensity focal stack by camera sensors. Then, phase space tomography (PST) combined with a non linear iterative algorithm is conducted to reconstruct the whole WDF. We further analyzed the effect of the imaging system, i.e. the illumination aperture and the aperture of objective lens effect.
SPIE/COS Photonics Asia