| 摘要 |
PURPOSE: To hold the degree of light modulation at a fixed value even when average output light intensity is changed by providing this light transmitter with a means for adjusting the intensity of an input signal so as to hold the degree of light modulation at the fixed value against the value of light intensity to be set up. CONSTITUTION: When an instruction for changing average output light intensity to a data setting circuit 6, the circuit 6 finds out the light intensity of a modulation signal from which the optimum degree of light modulation is obtained by the use of the average output light intensity and applies the modulation signal light intensity and the average output light intensity to a modulation signal light intensity setting circuit 5 and an output light intensity setting circuit 4 respectively as set values. The circuit 5 changes the set value of the modulation signal light intensity for a modulation signal light controlling circuit 2 to the value applied from the circuit 6. The circuit 4 changes the set value of light intensity for an output light control circuit 3 to the value applied from the circuit 6. The circuit 2 adjusts the intensity of an RF signal so that the modulation signal light intensity is held at the set intensity. |
