pdh_servo_v2

PDH servo v2

pdh_servo_v2 is a servo controller for locking lasers to high finesse optical cavities using the Pound-Drever-Hall technique. The board features the following:

• A PI^2D controller for > 1MHz locking bandwidth.
• Microcontroller controlled analog switches to turn the servo as well as the integrator switches on and off.
• Auto relocking sequence that detects when laser is out of lock, starts scanning the laser frequency to find resonance and re-engages the servo when the laser is in the capture region of the lock.
• WiFi enabled microcontroller for remote monitoring and control.

Pics of the assembled PCB and box:

This repository is arranged as follows:

• /kicad: board schmetic and pcb layout files
• /kicad/gerber/: gerber and drill files sent out to the PCB manufacturer
• /code/microcontroller: Particle photon controller code
• /qucs: Qucs simulation of the servo transfer function
• /docs: Bill of materials and misc. notes on board design.