Table 1.

Summary of optoelectronic devices for reservoir computing

Device type	Implementation	Key modulation mechanisms	Advantages	Limitations	Application
Photodiode (2-terminal)	Heterojunction, dual-absorber	- Optical modulation	- Simple fabrication - Fast response - Bidirectional weight - Low power	- Limited nonlinearity - Limited control of memory capacity	- Digit/face recognition
Optical memristor (2-terminal)	Inserted absorbance layer	- Resistive switching - Optical modulation	- STP–LTP tunable - Strong nonlinearity - Low power	- Slow response - Variability - Endurance	- Digit/Fingerprint recognition
Phototransistor (3-terminal)	Single channel	- Gate modulation - Optical modulation - Charge trapping	- STP–LTP tunable - Read/write separation - Tunable memory depth - Multi-level states	- Complex fabrication - Slow response - High power	- Digit recognition - Vehicle flow - Action recognition