摘要 |
<p>Light to be measured L and sampling pulse light L SP are each split into M beams, and a time delay of 0, T, 2T, ..., (M-1)T is given to each of the M-split sampling pulse light beams. The M-split light beams to be measured are then respectively multiplexed with M optical 90-degree hybrids, and M electrical field amplitudes per time T are determined for the light beam to be measured, based on M sets of output currents received at a balance light receiving element that receives light emitted from each of the optical 90-degree hybrids. The amplitudes of the respective wavelength optical signals contained in the light beam to be measured are calculated through Fourier transformations of the field electrical amplitudes. Pulsed light with a spectral width that covers the total frequency bandwidth of the light to be measured is used as the sampling pulse light. Where the total frequency bandwidth of the light to be measured is ”f total , and the frequency interval of the optical signals contained in the light to be measured is ”f, T ‰¤ 1/”f total and 1/(met) ‰¤ ”f are set.</p> |