Stanford Research LDC502 – Laser Diode Controller

The Stanford Research LDC502 is a precision laser diode controller delivering simultaneous current and temperature regulation for laboratory and industrial laser systems. It combines a low-noise current source with a high-precision TEC controller, enabling stable operation across demanding applications requiring microradian-level wavelength stability and sub-milliamp current resolution.

Technical Specifications

• Output: 0 to 2 A (2000 mA maximum) with selectable 0 to 1 A sub-range


• Setpoint resolution: 0.1 mA


• Accuracy: ±0.02% of full scale


• Thermal stability: <10 ppm/°C


• Short-term stability (1 hr): <5 ppm of full scale


• Long-term stability (24 hr): 1 MΩ (DC)


• Operating modes: Constant Current (CC) and Constant Power (CP) with dynamic mode switching


• Modulation bandwidth: Up to 1 MHz (CC mode) or 10 kHz (CP mode) Temperature Controller (TEC)


• Output power: 36 W


• Control range: −55 °C to +150 °C (IC sensors); −150 °C to +250 °C (resistor sensors, 10 Ω to 500 kΩ)


• Setpoint resolution: 0.001 °C


• Accuracy: 0.01 °C (calibrated sensor)


• Stability: 0.0005 °C/°C typical


• Sensor types: Thermistor, RTD, and IC sensors supported


• Auto-tuning for PID loop optimization Additional Outputs


• Compliance voltage: 0 to 10 V programmable (10 mV resolution, ±0.2 V accuracy)


• Photodiode monitor: 0 to 5 V bias, 0 to 10,000 µA range


• Rise/fall time: <20 µs

Key Features

• Slow-start turn-on with adjustable current limits and compliance voltage


• Multi-voltage AC input: 100 V, 120 V, 220 V, or 240 V nominal (50/60 Hz)


• Fast clamping protection for laser diode safeguarding

Typical Applications Fiber optics, telecommunications, spectroscopy, laser metrology, and precision optical instrument calibration.

Compatibility & Integration Supports standard thermistor, RTD, and integrated-circuit temperature sensors over extended operating ranges.