Stanford Research LDC500 – Laser Diode Controller

The Stanford Research LDC500 is a precision laser diode controller combining low-noise current sourcing with high-stability temperature control in a single instrument. It delivers current outputs to 100 mA with 1 µA resolution and ±0.02% full-scale accuracy, while the integrated TEC controller maintains temperature stability to 0.0005 °C/°C with 0.001 °C setpoint resolution. Designed for scientific and industrial laser systems requiring exceptional stability and low noise across DC to 1 MHz modulation frequencies.

Technical Specifications

• Output range: 0–100 mA (0–50 mA option available)


• Setpoint resolution: 1 µA


• Accuracy: ±0.02% of full scale


• Output impedance: >1 MΩ (DC)


• Noise floor (10 Hz–1 MHz): 0.3–0.9 µA rms depending on bandwidth and range selection


• Thermal stability: <10 ppm/°C


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


• Long-term stability (24 hours): <15 ppm full scale Temperature Controller


• Output power: 36 W


• Temperature stability: 0.0005 °C/°C


• Setpoint resolution: 0.001 °C


• Measurement accuracy: 0.01 °C (with calibrated sensor)


• Supported sensor types: Thermistor, RTD, IC sensors Power & Electrical


• AC line voltage: 100V, 120V, 220V, or 240V nominal (50–60 Hz)


• Fuses: 5 × 20 mm fast-blow (4 A for 100V/120V; 2 A for 220V/240V)

Key Features

• Dual-mode current operation: Constant Current (CC) and Constant Power (CP) with dynamic bumpless transfer


• Temperature control modes: Constant Temperature (CT) and Constant Current (CC) with automatic mode switching


• Auto-tuning of temperature loop parameters


• Analog modulation input supporting up to 1 MHz current modulation


• RF injection capability for higher-frequency modulation


• Adjustable current limits and compliance voltage


• Slow-start turn-on with fast clamping and shutdown protection


• Front-panel two-line blue alphanumeric display and dual 5-digit green LED readouts

Typical Applications Advanced laser systems, quantum optics, spectroscopy, and precision metrology requiring synchronized current and thermal stabilization.

Compatibility & Integration GPIB, RS-232, and Ethernet interfaces for remote instrument control and data logging.