A Scalable, Self-Analyzing Digital Locking System for use on Quantum   Optics Experiments
  Digital control of optics experiments has many advantages over analog control systems, specifically in terms of scalability, cost, flexibility, and the integration of system information into one location. We present a digital control system, freely available for download online, specifically designed for quantum optics experiments that allows for automatic and sequential re-locking of optical components. We show how the inbuilt locking analysis tools, including a white-noise network analyzer, can be used to help optimize individual locks, and verify the long term stability of the digital system. Finally, we present an example of the benefits of digital locking for quantum optics by applying the code to a specific experiment used to characterize optical Schrodinger cat states. 
B. M. Sparkes, H. M. Chrzanowski, D. P. Parrain, B. C. Buchler, P. K.   Lam, and T. Symul
physics.ins-det quant-ph