| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical signal transmission circuit capable of stabilizing the output power of a transmission light signal in a variable wavelength optical signal transmission circuit about the optical signal transmission circuit. SOLUTION: This optical signal transmission circuit for supplying the output light of a light emitting element to an external modulator and performing intensity modulation of the output light of the light emitting element according to the logical level of an input signal in the external modulator, fetches a part of the output light of the external modulator, electrically converts a part of the output light, performs at least automatic power control of the external modulator with the electrically converted signal, also fetches light that is proportional to the output light of the light emitting element, electrically converts the light and performs automatic power control of the light emitting element with the electrically converted signal. |
