摘要 |
<p>According to the present invention, a nonlinear optical loop mirror (40) is provided, which includes a first optical coupler (46) including first (42) and second (44) optical paths directionally coupled to each other, a loop optical path (48) formed of a nonlinear optical medium for connecting the first and second optical paths, and a second optical coupler (52) including a third optical path (50) directionally coupled to the loop optical path. An optical signal whose waveform is to be measured is supplied into the nonlinear optical loop mirror (40) from the first optical path (42). An optical trigger having a predetermined pulse width is supplied into the nonlinear optical loop mirror (40) from the third optical path (50). Information on the waveform of the optical signal is obtained according to light output from. the second optical path (44). The predetermined pulse width is set according to a required measurement accuracy, so that the waveform of the optical signal can be observed with a high time resolution. <IMAGE></p> |