A digital control system for the iodine stabilized He–Ne laser

A digital control system has been developed for the iodine stabilized He–Ne laser. The system is based on a digital signal processor and a general purpose microprocessor. The hardware is briefly described. The algorithms used for laser frequency locking are presented and new methods which are made possible by this system are discussed. An improved way of locking the laser to the fifth or seventh harmonic of the modulation frequency has been implemented digitally.