OPTICAL SIGNAL AMPLIFYING THREE-TERMINAL DEVICE, OPTICAL SIGNAL TRANSFER METHOD USING SAME, OPTICAL SIGNAL RELAY DEVICE, AND OPTICAL SIGNAL STORAGE DEVICE
An optical signal amplifying three- terminal device (10) for directly amplifying an optical signal by using a control input light. A first input light L1 of a first wavelength lambda1 and a second input light L 2 of a second wavelength lambda2 are inputted into a first optical amplifying element (26). A light of the second wavelength lambda 2 and a third input light (control light) L3 of a third wavelength lambda3 outputted from the first optical amplifying element (26) are inputted into a second optical amplifying element (34). An output light L4 of the third wavelength lambda3 selected from the light outputted from the second optical amplifying element (34) is modulated with the intensity variation of the first input light L1 and/or the third input light L3.
Therefore, the output light L4 is an amplified signal amplified with a signal amplification factor of 2 or more with respect to the third input light (control light) L3. Thus, an optical signal is directly amplified by using a control input light.