ILX Lightwave LDC-3736 – 4 Amp Laser Diode Controller

The ILX Lightwave LDC-3736 is a 4 A laser diode controller combining a high-stability, low-noise current source with a high-power thermoelectric temperature controller. Engineered for precision laser control in research, production, and specialized applications including Quantum Cascade Lasers, the instrument delivers independent management of laser current and temperature with multiple protection layers against transients, over-current conditions, and electrostatic discharge.

## Technical Specifications

**Laser Current Source**
• Maximum output current: 4 A across three selectable ranges (1 A, 2 A, 4 A)
• Compliance voltage: 18 V
• Current resolution: 0.1 mA (display), 80 µA (remote, 4 A range)
• Current accuracy: ±0.15% of setpoint ± 1 mA or ±0.1% FS
• 1-hour stability: <20 ppm FS; 24-hour stability: <40 ppm FS
• Output noise/ripple (low bandwidth): <30 µA or <50 µA (rms)
• Output noise/ripple (high bandwidth): <30 µA or <60 µA (rms)
• Analog modulation bandwidth: Up to 250 kHz; supports up to 1 MHz modulation in high-bandwidth mode
• Temperature coefficient: <50 ppm/°C
• Laser forward voltage measurement via 4-wire configuration

**Thermoelectric Temperature Controller**
• TE current range: −8.00 to +8.00 A
• TE voltage range: −16.00 to +16.00 V
• Output power: 128 W
• Temperature stability: Typically ±0.003°C
• 1-hour current stability: ±0.002°C; 24-hour stability: ±0.003°C
• TEC ripple/noise: <2.5 mA (rms)
• Compatible sensors: Thermistor, IC, RTD

**Photodiode Monitoring**
• Photodiode current range: 0 to 10 mA
• Current resolution: 1 µA; accuracy: ±4 µA
• Responsivity range: 0.00–1000.00 µA/mW

**Optical Power Measurement**
• Range: 0.00–20000.0 mW; resolution: 0.1 mW

## Key Features

• Three operating modes: constant current (low and high bandwidth) and constant optical power via rear-facet or external photodiode feedback
• Slow-start routine protecting against over-current and turn-on transients
• Adjustable current and voltage limits with clamping under modulated conditions
• Intermittent contact and electrostatic discharge protection
• Output shorting relays (mechanical and MOSFET) for power-up safety

## Typical Applications

Research and development, production environments, Quantum Cascade Laser systems, and wavelength/power tuning applications requiring modulation.

## Compatibility & Integration

Supports thermistor, IC, and RTD temperature sensors. Accepts rear-facet or external photodiode feedback for constant optical power control.