Integrated photonic device and photonic integrated circuit using the same

A photonic integrated circuit, comprising:

• a substrate having a light input port and a light output port;
• a functional photonic device formed on the substrate;
• an integrated photonic device mounted on the substrate;
• and
• optical waveguides formed on the substrate and including
• a first waveguide coupled between the light input port and the integrated photonic device,
• a second waveguide coupled between the light output port and the integrated photonic device, and
• third waveguides coupled between the functional photonic device and the integrated photonic device,
• wherein the functional photonic device, the integrated photonic device, and the light output port are configured without intersection,
• wherein the integrated photonic device has an array of two or more semiconductor optical amplifiers, and includes a first semiconductor optical amplifier having a first gain region and a second gain region connected by a first connecting waveguide, and a second semiconductor optical amplifier provided in parallel with the first semiconductor optical amplifier and having a third gain region and a fourth gain region connected by a second connecting waveguide, and
• wherein the first gain region and the second gain region define a first gain region pair, and the third gain region and the fourth gain region define a second gain region pair, the second gain region pair being disposed within the first gain region pair, and the first connecting waveguide is configured to connect the first gain region and the second gain region on an outer side of the second connecting waveguide.