High bandwidth travelling wave electro absorption modulator (EAM) chip

An integrated electro-absorption modulator (EAM)-laser device comprising:

• a semiconductor laser comprising a laser part of a continuous multi-quantum well (MQW) layer;
• a waveguide mesa comprising a waveguide part of the continuous MQW layer;
• a segmented travelling wave electrode (TWE) comprising a plurality of electrode segments disposed on the waveguide mesa;
• and
• a microstrip transmission line disposed on an insulating spacer layer and in electrical communication with the segmented TWE structure via conducting bridges,
• wherein:
• the waveguide mesa comprises alternating active sections and passive sections,
• an electrode segment of the plurality of electrode segments is disposed on a respective one of the active sections,
• portions of the waveguide section the continuous MQW layer disposed in respective longitudinal portions of each of the active sections have an energy gap defining an active energy gap value,
• portions of the continuous MQW layer disposed in respective longitudinal portions of each of the passive sections have an energy gap defining a passive energy gap value, and
• each active energy gap value is less than each passive energy gap value.

A method of fabricating an electro-absorption modulator (EAM) device, the method comprising:

• forming a continuous multi-quantum well (MQW) layer of a waveguide mesa;
• and
• forming a plurality of electrode segments on the waveguide mesa,
• wherein:
• the waveguide mesa comprises alternating active sections and passive sections,
• portions of the waveguide mesa having an electrode segment of the plurality of electrode segments disposed thereon are active sections of the waveguide mesa,
• portions of the continuous MQW layer disposed in respective longitudinal portions of each of the active sections have an energy gap defining an active energy gap value,
• portions of the continuous MQW layer disposed in respective longitudinal portions of each of the passive sections have an energy gap defining a passive energy gap value, and
• each active energy gap value is less than each passive energy gap value;
• and
• forming a microstrip transmission line on an insulating spacer layer and in electrical communication with each of the plurality of electrode segments via conducting bridges.