Abstract: The present invention has been achieved to provide a novel optical transmission system realizing high-speed optical transmission over greater distance by suppressing waveform degradation caused by mode dispersion and mode transition in a multimode optical transmission line. The optical transmission system of the present invention includes: an optical transmitter for transmitting incoherent light; an excitation mechanism for exciting a predetermined mode in the incoherent light transmitted from the optical transmitter; a multimode optical transmission line for transmitting the incoherent light transmitted from the excitation mechanism; a transmission mechanism for transmitting a predetermined mode in the incoherent light transmitted from the excitation mechanism; and an optical receiver for receiving the incoherent light transmitted from the transmission mechanism or the incoherent light transmitted from the transmission mechanism.

Abstract: An analog signal measuring apparatus has: a sampling gate circuit, having a plurality of input terminals including an analog signal input terminal and a feedback signal input terminal, for generating an output signal of high or low level when a sum of input signals goes beyond or falls below a predetermined threshold value; a signal generating circuit, connected to an output terminal of the sampling gate circuit, for changing an output signal by a predetermined level toward a direction in which an output signal level of the sampling gate circuit is inverted when a trigger signal is applied to the signal generating circuit, and for supplying a feedback signal to the feedback signal input terminal of the sampling gate circuit; and a read circuit for generating a value obtained when the feedback signal from the signal generating circuit converges, the feedback signal corresponding to a value of an analog signal supplied to the analog signal input terminal, wherein a ratio of an increment .DELTA.