Electro-absorption modulator and optical semiconductor device

An electro-absorption modulator, comprising:

• a semi-insulating semiconductor layer;
• a first electro-absorption modulator section including a first n-type semiconductor layer, a first absorption layer, and a first p-type semiconductor layer which are grown in the stated order on the semi-insulating semiconductor layer;
• a second electro-absorption modulator section including a second p-type semiconductor layer, a second absorption layer, and a second n-type semiconductor layer which are grown in the stated order on the semi-insulating semiconductor layer;
• a connection waveguide layer arranged between the first absorption layer and the second absorption layer;
• a first EA electrode electrically connected to the first p-type semiconductor layer and electrically connected to an outside;
• a second EA electrode electrically connected to the second n-type semiconductor layer and electrically connected to the outside;
• and
• a connection medium configured to electrically connect the first n-type semiconductor layer and the second p-type semiconductor layer to each other to connect the first electro-absorption modulator section and the second electro-absorption modulator section in series to each other.