Frequency tracking twin-channel waveguide lasers

An array of RF-excited waveguide lasers provides the means of producing independent laser sources whose frequencies naturally track to high accuracy. A two-channel array system with active locking of the difference frequency to a tunable electrical oscillator, giving further improvement in stability and rapid control of the offset, is presented. It has been demonstrated that this approach makes available laser sources with exceptional stability in their frequency offset. Variation (e.g., chirping) of the interchannel frequency can be achieved by tuning the oscillator. Further control over the absolute frequency can be implemented using traditional methods acting on one of the channels, if required. The concept is scalable to 2-D multiple channels to produce an array of different frequencies with predetermined precise offsets.