Pound-Drever-Hall Signal Unit: PDH-1000-5C

The Pound-Drever-Hall error signal is a pillar of modern laser frequency stabilization.

Our fully-integrated PDH unit helps you achieve ultralow noise error signals without the need for bulky RF generators or long, lossy RF delay lines. We’ve combined a fast transimpedance amplifier, an RF output signal driving an EOM phase modulator, and lock-in detection in an RF-shielded enclosure to generate a crisp, clean PDH error signal. We offer full customization, from choice of fiber-coupled or free-space photodetector in silicon, InGaAs, or extended InGaAs.

The best cavity locking starts with the best error signals

Performance & Specs

Operating Wavelengths 500-2050 nm Chosen at time of order
Photodetector input noise < 7 pA/ √Hz
Modulation output frequency 5 MHz standard Up to 50 MHz custom
Modulation output amplitude 4 Vpp Adjustable via front panel
Error Signal amplitude 300 mVpp (typical) Some board adjustment of gain is available.
Error Signal ripple < 15 mV Includes components from fmod and 2xfmod
Dimensions 75 x 125 x 70 mm (H) M6 mounting hole provided


  • Compatible with any laser stabilization system
  • Fully-integrated detector, RF oscillator, and filter in a compact, RF-shielded package
  • Generates RF output signal to drive an external EOM phase modulator
  • Phase of local oscillator adjustable over 160 degrees from front panel
  • Generate robust, ultralow noise PDH error signals


  • Cavity frequency stabilization
  • Can be modified for residual amplitude modulation detection

Customization Options

  • Fiber-coupled or free-space photodetector
  • Choice of silicon, InGaAs, or extended InGaAs photodetector
  • Modulation frequency may be chosen at time of order, up to 50 MHz