Precision Electro-Optic and Laser Technologies

D2-105 Laser Controller

Contact Vescent



  • New! Modified PID parameters for easier temperature control over low thermal mass lasers
  • Lowest noise current source commercially available
  • Two-stage PID temperature control
  • High-speed servo and RF inputs
  • Current limit and safe turn-on
  • High modulation bandwidth





The D2-105 is a precision diode laser current source based on the Libbrecht-Hall* circuit. With a current noise density <100 pA/√Hz, the D2-105 has lower noise than any other commercially available laser controller. This ultra-low current noise is ideally suited for precision spectroscopy and metrology applications. Furthermore, two-stages of temperature control provide sub-mK stability, ensuring long-term frequency stability.

A front panel current servo BNC input enables high-speed (>10 MHz) servo control of the laser frequency. Additionally, extremely high speed modulation is enabled by a front panel RF port, which is connected directly to the laser current output SMA. This enables the user to directly write sidebands onto the laser via injection current, which can save the use of expensive AOMs and EOMs. To keep 60 Hz harmonics off the output current, the D2-105 is powered with either the linear D2-005 power supply or user-provided power via a breakout board (D2-001).

The D2-105 features two independent PID loop filters for controlling the temperature of your diode laser. The range of parameters one of these loops is expanded to make it especially easy to temperature control low thermal mass lasers such as the Photodigm TOSA.

*Libbrecht and Hall, A Low-Noise, High-Speed Current Controller, Rev. Sci. Inst. 64, pp. 2133-2135 (1993).

The D2-105 is designed to integrate  into our Rackless Rack.  As such, it may be powered with our D2-005  or from an adjacent D2 electronics module.  If used as a stand-alone product it may be powered with either a D2-005 or from a user-supplied power supply via a breakout board.

D2-105-200 D2-105-500 Units
Current Source
Current Range 0-200 0-500 mA
Current Noise Density <100 <200 pA/√ Hz
RMS Noise (10Hz – 100 kHz) <50 <100 nA
RMS Noise (10Hz – 1 MHz) <100 <150 nA
RMS Noise (10Hz – 10MHz) < 300 < 500 nA
Monitor Resolution (Display) 0.1 1 mA
Absolute Accuracy 2 2 %
Temperature Coefficient <1 <5 μA/oC
Current Servo Input
Input Impedance 1000 1000 Ω
Bandwidth >10 >10 MHz
Modulation Coefficient 1 1 mA/V
Input Modulation Range ±10 ±10 V
RF Input Bandwidth 0.5 to >1,500 0.5 to >1,500 MHz
Temperature Servo Input
Input Impedance 100 100
Temp. Modulation Coefficient
Gain = Low -20 -20 mK/V
Gain = High -600 -600 mK/V
Temperature Control
Temperature Setpoint Range 1 to 50 1 to 50 oC
Long-term Stability (T2) mK/day
Max. TEC Current (Voltage) 1 (4) 1 (4) A (V)