4300 Series LaserSource

The 4300 Series LaserSource is a high-accuracy laser driver capable of supplying up to 20A for low and medium-power laser and LED applications. This laser driver offers features typically found in only more expensive units, such as overlapping laser protection systems and an optional QCW mode.


Current Ranges:

  • 2 Amp / 15 Volt
  • 4 Amp / 8 Volt
  • 8 Amp / 4 Volt
  • 20 Amp / 5 Volt
  • Custom Configurations

High Accuracy

  • Up to 0.025% of reading + 0.025% of scale

Low Noise

  • As Low as <20 μA

Compliance Voltages

  • Up to 24 Volts available
4302-QCW LaserSource, 2A, QCW2 A15 V0.05% + 0.4 mA< 20 uA65 kHzYes
4304-QCW LaserSource, 4A, QCW4 A8 V0.05% + 0.8 mA< 30 uA50 kHzYes
4308-QCW LaserSource, 8A, QCW8 A4 V0.05% + 1.6 mA< 60 uA40 kHzYes
4320-QCW LaserSource, 20A, QCW20 A5 V0.05% + 4 mA< 5 mA10 kHzYes
4302 LaserSource, 2A2 A15 V0.05% + 0.4 mA< 20 uA65 kHzNo
4304 LaserSource, 4A4 A8 V0.05% + 0.8 mA< 30 uA50 kHzNo
4308 LaserSource, 8A8 A4 V0.05% + 1.6 mA< 60 uA40 kHzNo
4320 LaserSource, 20A20 A5 V0.05% + 4 mA< 5 mA10 kHzNo


The 4300 Series LaserSource is the ideal laser driver for medium power applications, including high power pump lasers, freespace lasers, and high power fiber-pigtailed devices and it works well with many high power LED devices. Our compact enclosure takes up very little of your workspace, and the price offers excellent value.

The LaserSource has all the features you would expect from a laser driver, such as safety interlock, ESD protection, and hardware limit circuits for current and voltage. In addition, the LaserSource has unique features not found on competing products including optically isolated modulation and photodiode inputs, programmable PD bias, and a constant voltage control mode.

The 4300 Series also offers an optional Quasi-CW (QCW) mode, a feature only found on far more expensive units. Using QCW mode, you can operate the device at a low duty cycle, mitigating the thermal loading on the device, and allowing you to run at higher output powers than CW operation allows. The special measurement circuitry in the 4300 even allows you to take measurements in QCW mode, which would not be possible with external triggering.


Including safety interlock, ESD protection, hardware limits for current & voltage, soft power-on, and intermittent contact safeguards.


QCW mode provides low duty cycle, high current pulses to manage thermal loading. Rise times less than 20μs. Pulse widths as narrow as 100 μs.


Bandwidths up to 65 kHz.


Choose from: Constant Current, Constant Power, Constant Voltage


Easy to Read, High Contrast VFD Display with all messages and settings in plain English. View All 3 At Once:

  • Current Set Point
  • Photodiode Current
  • Laser Voltage


Menu-selectable PD bias voltage, from 0 to -5 Volts.