EXPERIMENTAL INVESTIGATION OF CROSSTALK DURING MULTIPLE-BEAM TRANSMISSION ALONG AN OPTICAL WAVEGUIDE COMMUNICATIONS LINE.

It is known that the informational capacity of an optical communications line can be increased considerably if so-called multiple-beam transmission is implemented in it. However, the instability of the position of the beams within the cross section of the receiver, arising because of fluctuations in the refractive index of the air in the shielding conduit, as well as the scattering fields, caused by imperfections in the surfaces of the optical elements, lead to the appearance of crosstalk in the line. Therefore in an investigation of the possibility of realizing multiple-beam transmission considerable attention must be directed at the problem of estimating the crosstalk level. This note reports an investigation of the relative amount of light energy arriving at the receiver aperture from the adjacent optical shaft.