ILX Lightwave LDC-3724B: 200/500 mA Laser Diode Controller, LDC-3700 Series

The ILX Lightwave LDC-3724B is a microprocessor-based laser diode controller delivering precise, low-noise current and temperature management for laser diode testing and characterization. Part of the LDC-3700 Series, this instrument combines a dual-range current source (0–200 mA or 0–500 mA) with a 32 W temperature controller, addressing applications requiring stable operation of low to medium power laser diodes. Selectable current ranges, four-wire forward voltage measurement, and photodiode feedback capability enable flexible experimental configurations. Built-in protection includes slow start, adjustable current and compliance voltage limits, and intermittent contact protection for extended diode life.

## Technical Specifications

**Laser Diode Current Source**
• Output current ranges: 0–200 mA or 0–500 mA (user selectable)
• Setpoint resolution: 4 µA (200 mA range) / 10 µA (500 mA range)
• Accuracy: ±0.05% of Full Scale
• Current stability: < 40 ppm/°C
• Noise and ripple: < 1.5 µA
• Drive current limit: 1–202 mA (200 mA range) or 1–505 mA (500 mA range), ±2 mA / ±5 mA accuracy respectively
• Compliance voltage: 0–10 V adjustable, ±2.5% accuracy, 50 mV resolution
• Operating modes: Constant Current or Constant Power
• Analog modulation bandwidth: DC to 1 MHz

**Temperature Controller**
• Output power: 32 W maximum
• Temperature control range: −100°C to 199.9°C
• Setpoint resolution: 0.01°C or 0.1°C
• Measurement accuracy: 0.05°C (with calibrated sensor)
• Temperature stability: ±0.004°C
• TEC output current: −4 A to +4 A
• TEC current limit: 0 to 4 A
• Control modes: Constant Temperature, Constant Sensor, or Constant TE Current

**Photodiode Feedback**
• Monitor photodiode measurement range: 5 to 5000 µA
• Setpoint accuracy: ±0.05%

**Power Requirements**
• Input: 100–120 VAC (±10%)

## Key Features

• Four-wire laser forward voltage measurement for accurate diode characterization
• Multiple temperature sensor compatibility: thermistor, IC, and RTD
• Adjustable compliance voltage with 50 mV resolution
• Integrated photodiode feedback for closed-loop optical power control
• Multi-layer laser diode protection architecture

## Typical Applications

• Laser diode characterization and testing
• Research and development of semiconductor lasers
• Optical communication component evaluation
• Precision optical power stabilization

## Compatibility & Integration

The LDC-3724B accepts thermistor, IC, and RTD temperature sensors. Forward voltage measurement employs four-wire topology for improved accuracy over extended cable runs. Photodiode feedback enables optical power monitoring and regulation across the 5–5000 µA measurement range.