High-precision digital automated measurement of degree of coherence in the Thompson and Wolf experiment

Abstract

We propose a high-precision digital automated quantitative determination of the modulus of the complex degree of coherence. The Thompson and Wolf experiment is repeated, using a CCD and a measurement method based on the fast Fourier transform. The experimental results agree very well with the predictions of the theory.

Coherence characteristics of light-emitting diodes

“…In the present study we used Fourier transform fringe analysis technique to determine the visibility of the interference fringes [15][16][17]. According to this technique an interferogram g (x, y; t) with two-dimensional spatial carrier frequencies can be expressed by [15][16][17] gðx; y; tÞ ¼ ðI 1 ðx; yÞ…”

“…According to this technique an interferogram g (x, y; t) with two-dimensional spatial carrier frequencies can be expressed by [15][16][17] gðx; y; tÞ ¼ ðI 1 ðx; yÞ…”

“…The three Fourier spectra given in Eq. (7) can be widely separated if the spatial carrier frequency is very large, i.e., 2/L, L being the width of rectangular window [16]. The first-order spectrum of the Fourier transform gives information about the depth of modulation, i.e., visibility and phase of the interference fringes.…”

“…Experiments were performed using red and green color LEDs directly illuminating the Young's double slit kept in the far-zone. Fourier transform fringe analysis [15][16][17] technique was used for measurement of the visibility of interference fringes. Poor visibility of interference fringes was observed.…”

Teaching stellar interferometry with polymer optical fibers

“…This subject is largely ignored in most astronomy textbooks [1] and only the classic Michelson interferometer is briefly acknowledged [2]. On the other hand, although the Michelson stellar interferometer for determining the angular dimensions of astronomical objects is described in classic textbooks of optics [3,4], little has been written concerning experimental activities related to the optical principles of that type of interferometer, with the exception of some few works [5][6][7][8]. It is worth mentioning the experiment for undergraduate students reported by J.P. Sharpe and D.A.…”