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.