Measurements of spatial coherence of partially coherent light with and without orbital angular momentum

2010 ◽  
Vol 27 (12) ◽  
pp. 2630 ◽  
Author(s):  
H. Di Lorenzo Pires ◽  
J. Woudenberg ◽  
M. P. van Exter
1991 ◽  
Vol 131 ◽  
pp. 10-14
Author(s):  
Daniel F.V. James

The interferometric mapping of astronomical objects relies on the van-Cittert Zernike theorem, one of the major results of the theory of partially coherent light [see, Bom and Wolf (1980), chapter 10]. This theorem states that the degree of spatial coherence of the field from a distant spatially incoherent source is proportional to the Fourier transform of the intensity distribution across the source. Measurement of the degree of spatial coherence, by, for example, measuring the visibility of interference fringes, allows the object to be mapped by making an inverse Fourier transform. (For a full description of this technique see Thompson, Moran and Swenson, 1986.)In this paper I present a summary of the results an investigation into what happens when the distant source is not spatially coherent (James, 1990). Using a heuristic model of a spherically symmetric partially coherent source, an analytic expression for the error in the measurement of the effective radius, expressed as a function of coherence area, can be obtained.


2021 ◽  
Vol 51 (2) ◽  
Author(s):  
Yushuang Wang ◽  
Xuanxuan Ji ◽  
Ziyang Chen ◽  
Jixiong Pu

We develop a Q-switched degenerate laser, delivering a partially coherent light pulse of duration about 16 ns. The spatial coherence of the output laser pulse can be varied by tuning the spatial filter inside the laser resonator, and the oscillating transverse mode structure can be determined by measuring the degree of coherence of the output laser pulse. It is shown that the larger is the diameter of the spatial filter, the more are the oscillating transverse modes, and the lower is the degree of coherence. Based on coherent-mode representation for the partially coherent source, we can estimate the transverse mode contribution to the output partially coherent laser. The experimental results on suppressing speckle demonstrate that the generated partially coherent light possesses the characteristics of rapid reduction of spatial coherence, making it an ideal source for high-speed imaging and ranging applications.


2018 ◽  
Vol 26 (3) ◽  
pp. 2928 ◽  
Author(s):  
J. Alejandro Gonzaga-Galeana ◽  
Jorge R. Zurita-Sánchez

1979 ◽  
Vol 129 (9) ◽  
pp. 151
Author(s):  
G.S. Egorov ◽  
S.N. Mensov ◽  
Nikolai S. Stepanov

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