PSEUDO ACCUMULATED CROSSTALK GENERATOR AND RECEPTION CIRCUIT EVALUATION DEVICE USING THE GENERATOR

摘要

PROBLEM TO BE SOLVED: To provide a generator that generates accumulated crosstalk caused by lots of optical signal sources in a pseudo way with a few number of optical signal sources. SOLUTION: An output signal from an optical signal source 101 is distributed into two by a 2×2 photocoupler 102, the one optical signal passes through a delay line 109, in which the signal is delayed by a time τ from the optical signal through an optical fiber 108. A 2×2 photocoupler 103 superimposes the two optical signals and the superimposed signal is outputted from two output terminals. The similar processing is conducted by each stage. In this case, a delay time of the delay line at the i-th stage is 2<(i-1)> τ. As a result, an output signal of the 2×2 photocoupler 106 is a result of superimposing 2 kinds of optical signals whose delay time is from 0 to (2 -1)τ at an interval of τ and the signal is regarded as an accumulated crosstalk. Then the accumulated crosstalk and the optical signal from an optical signal source 114 are superimposed and received by a reception circuit 105 and the effect of the accumulated crosstalk in this circuit is evaluated.