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4201-DR LaserSource, 50mA/100mA

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4201-DR LaserSource, 50mA/100mA Click here for larger image(s)

The 4201-DR LaserSource is well suited for low power applications, offering an excellent combination of low noise, accuracy, and resolution. If your working with VCSELs, quantum dot lasers, or other low power devices, the 4201-DR provides a very precise, very accurate driver well suited for these types of devices.

Dual Range
One of the key new features of the 4201-DR is the dual range capability, which allows operation in either a 50mA range or 100mA range. For applications that need less than 50mA, the lower range offers higher accuracy, lower noise, and improved stability, while still maintaining the 100mA range for higher power devices.

Simple User Interface
The 4201-DR’s user interface is remarkably simple… so easy to use, you’ll have it up and running in no time. Unlike other instruments which rely on 7-segment LED displays and a confusing array of indicators and buttons, the 4201-DR instead presents the information on a high contrast VFD display in an easy-to-read format. The 4201-DR displays current, voltage, and photodiode current simultaneously… no need to toggle though the readings like on most instruments. Settings and error messages are in clear English, not cryptic codes and flashing status lights.

Programmable PD Bias Voltage
Unlike other laser drivers, the 4201-DR includes a software programmable PD bias voltage, from 0 to -5V, so selecting your bias voltage has never been easier. Simply adjust the voltage in the user menu or via a software command… no more fumbling around with a DMM and screwdriver to adjust the trim pot.

  • User selectable 50mA or 100mA range
  • 0.002mA resolution (50mA range)
  • <1uA noise
  • USB interface


USB Interface Standard
The 4201-DR includes a USB computer interfaces, allowing for quick and easy connection to a PC for remote operation. In addition, the LaserSource’s command set is compatible with ILX and Newport controllers, allowing you to leverage any existing software you may have already developed.

Ground Loops Eliminated
Like all LaserSources, the 4201-DR includes isolated inputs and outputs. In technical terms, this means that every input and output signal is electrically isolated, so that offset voltages, ground connections, and AC noise will not “bleed” into other parts of the electronics. Even the photodiode input is fully isolated from the laser output, ensuring full isolation of the laser output. In practical terms, this means it’s impossible to create a ground loop through the LaserSource, a common problem in laboratory setups where several different instruments are used in the same test. No other driver on the market has this capability.

Analog Modulation
The 4201-DR's analog interface supports modulation via the rear BNC jack.



CW Mode Specifications

    LASER CURRENT (Low / High)
    Range (mA)

0 – 50 / 0 – 100

    Resolution (mA)

0.002 / 0.005

    Setpoint Accuracy (±[% set+mA])

0.025% + 0.02 / 0.025% + 0.03

    Measurement Accuracy (±[% reading+mA])

0.025% + 0.02 / 0.025% + 0.03

    Stability (ppm, time)

< 10, 1 hour

    Temperature Coeff (ppm/°C)


    Noise/Ripple (μA rms, low BW)

< 1 / < 1

    Transients (μA)

< 50

    Compliance Voltage (V)


    Modulation Bandwidth (kHz)


    Modulation Input Range

0 – 10V, 10kΩ

    Range (μA)

5 – 5,000

    Resolution (μA)


    Setpoint Accuracy (±[% set+μA])

0.05% + 1

    Measurement Accuracy (±[% reading+μA])

0.05% + 1

    Stability (ppm, time)

< 200, 24 hours

    Temperature Coeff (ppm/°C)

< 200

    PD Bias (V)

0 to -5V, software programmable

    Range (V)

0 – 10

    Resolution (V)


    Setpoint Accuracy (±[% set+V])

0.05% + 0.005

    Measurement Accuracy (±[% reading+V])

0.05% + 0.005

    Stability (ppm, time)

< 50, 1 hour

    Temperature Coeff (ppm/°C)

< 100



    Current Limit Accuracy (mA)


    Voltage Limit Accuracy (±% FS)




    Display Type

2x20 VFD

    Laser Connector

DB-9, female

    Computer Interface

USB 2.0 Full Speed (Type B)

    Input Power

100V / 120V / 230V
50 / 60Hz

    Size (H x W x D) [inches (mm)]

1.82 (47) x 8.5 (215) x 11.13 (283)

    Operating Temperature

+10°C to +40°C

    Storage Temperature

-20°C to +60°C