Abstract: A monolithic optoelectronic integrated circuit is provided, including: a substrate including photonic integrated device region and a peripheral circuit region; a first GaN-based multi-quantum well optoelectronic PN-junction device including a first P-type ohmic contact electrode and a first N-type ohmic contact electrode; and a first GaN-based field-effect transistor, where the first GaN-based field-effect transistor includes a first gate dielectric layer disposed on the surface of the substrate and having a first recess, a first gate filled within the first recess, and a first source and a first drain that are disposed the opposite sides of the first gate, where the first source is electrically connected to the first P-type ohmic contact electrode, the first drain is configured to be electrically connected to a first potential.

Abstract: An electric motor positioning device for an electric motor includes a photoelectric sensor and a positioning ring. The positioning ring includes a first area and a second area. The electric motor includes a rotor and a stator. The rotor is rotatably mounted on the stator. One of the photoelectric sensor and the positioning ring is fixed on the rotor and rotates with the rotor, and the other one of the photoelectric sensor and the positioning ring is fixed on the stator. A position of the photoelectric sensor relative to the positioning ring rotates within a predetermined range with a relative rotation between the rotor and the stator, and the predetermined range includes a boundary between a first area and a second area.