A periodic optical output diagnostic device for an optical
transceiver comprising, in order, a
driving circuit according to the present invention, an
optical transmitter including a
laser diode or LED, a first optical connector, an optical cable, a second optical connector, and an optical
receiver, comprises: a first
voltage measuring unit connected to the
driving circuit of the
optical transmitter to measure a
voltage drop generated by a current
signal input to the
optical transmitter; the first optical output measuring unit connected to the rear end of the optical
transmitter to verify the output of the optical
transmitter; a second optical output measuring unit for measuring the output level of an
optical link including the optical
transceiver to calculate optical loss in the
optical link; and the second
voltage measuring unit for measuring the output voltage of a circuit in which an optical
signal is demodulated into a current
signal in the optical
receiver. The apparatus is characterized by comprising: an
optical attenuator for adjusting the optical attenuation rate of the optical cable based on the output voltage measured by the second voltage measuring unit; and an optical output diagnostic
control unit connected to each of the first voltage measuring unit, the first optical output measuring unit, the second optical output measuring unit, the
optical attenuator, and the second voltage measuring unit, and calculating one or more of the values of an optical
transmitter output (
dBm), a total link loss (
dBm), a final reception sensitivity (
dBm), or an optical output margin (dBm) based on data from the first voltage measuring unit, the first optical output measuring unit, the second optical output measuring unit, the
optical attenuator, and the second voltage measuring unit.