Electroabsorption modulator integrated distributed feedback laser with integrated semiconductor optical amplifier, and driving method for same

1. A driving method for an SOA (Semiconductor Optical Amplifier) integrated EA-DFB (Electroabsorption modulator integrated Distributed Feedback) laser, the SOA integrated EA-DFB laser monolithically-integrating a DFB laser portion, an EA (Electroabsorption) modulator portion provided in the latter part of the DFB laser portion and an SOA portion provided in the latter part of the EA modulator portion, on a same substrate, comprising:

injecting an electric current I SOA into the SOA portion within a range of a power consumption not exceeding a total amount of a power consumption eliminated in the DFB laser portion of the SOA integrated EA-DFB laser and a power consumption eliminated in the EA modulator portion of the SOA integrated EA-DFB laser by eliminating an elimination amount ΔI DFB from a maximum injection electric current into a DFB laser portion of an EA-DFB laser allowable in a case of mounting the EA-DFB laser on an optical transmission module.

2. The driving method according to claim 1 , wherein, when

a length of the SOA portion in regard to an optical waveguide direction is indicated at L SOA , the electric current is injected into the SOA portion within a range in which I SOA =115 [mA/mm]×L SOA [mm]+10 [mA]±ΔI DFB /2 [mA] for the driving.

3. The driving method according to claim 1 , wherein the electric current is injected into the DFB laser portion and the SOA portion in the SOA integrated EA-DFB laser from a same control terminal, and

a length of each of the DFB laser portion and the SOA portion in the SOA integrated EA-DFB laser in regard to an optical waveguide direction is designed to satisfy that I SOA =115 [mA/mm]×L SOA [mm]+10 [mA]±ΔI DFB /2 [mA].

4. The driving method according to claim 1 , wherein a length of the SOA portion in regard to an optical waveguide direction is from 50 μm to 150 μm.

5. An SOA (Semiconductor Optical Amplifier) integrated EA-DFB (Electroabsorption modulator integrated Distributed Feedback) laser in which an SOA portion is integrated in an emitting end of an EA-DFB laser including a DFB laser portion and an EA (Electroabsorption) modulator portion,

wherein an electric current I SOA is injected into the SOA portion within a range of a power consumption not exceeding a total amount of a power consumption eliminated in the DFB laser portion of the SOA integrated EA-DFB laser and a power consumption eliminated in the EA modulator portion of the SOA integrated EA-DFB laser by eliminating an elimination amount ΔI DFB from a maximum injection electric current into a DFB laser portion of an EA-DFB laser allowable in a case of mounting the EA-DFB laser on an optical transmission module.

6. The SOA integrated EA-DFB laser according to claim 5 , wherein, when a length of the SOA portion in regard to an optical waveguide direction is indicated at L SOA , the electric current is injected into the SOA portion within a range in which I SOA =115 [mA/mm]×L SOA [mm]+10 [mA]±ΔI DFB /2 [mA].

7. The SOA integrated EA-DFB laser according to claim 5 , wherein the electric current is injected into the DFB laser portion and the SOA portion in the SOA integrated EA-DFB laser from a same control terminal, and

a length of each of the DFB laser portion and the SOA portion in the SOA integrated EA-DFB laser in regard to an optical waveguide direction is designed to satisfy that I SOA =115 [mA/mm]×L SOA [mm]+10 [mA]±ΔI DFB /2 [mA].

8. The SOA integrated EA-DFB laser according to claim 5 , wherein a length of the SOA portion in regard to an optical waveguide direction is from 50 μm to 150 μm.