Optical switch

An optical switch having one optical input port, and N-th optical output ports where N is an integer of 2 or more,

• the optical switch, comprising:
• 2-input 2-output optical switches connected in a multistage for branching an optical signal inputted to the optical input port into N-th optical signals;
• N-th optical gates respectively provided at the optical output ports;
• driving circuits for operating the 2-input 2-output optical switches;
• and
• driving circuits for operating the N-th optical gates independently of the 2-input 2-output optical switches;
• wherein the driving circuits for operating the 2-input 2-output optical switches are integrated adjacent to a control electrode set on waveguides included in the 2-input 2-output optical switches,
• the driving circuits for operating the N-th optical gates are integrated adjacent to a control electrode set on waveguides included in the N-th optical gates,
• the waveguide included in the 2-input 2-output optical switch and the waveguide included in the N-th optical gates each have a p layer, an i layer, and an n layer sequentially formed on a semi-insulating substrate,
• a trench reaching the semi-insulating substrate is included between the 2-input 2-output optical switches and the N-th optical gates, and the trench isolates the p layer in an area of the 2-input 2-output optical switches and a p layer in an area of the N-th optical gates.