Tunable laser oscillator

摘要

A laser oscillator having a laser which produces a laser output signal tuned to a desired frequency as a result of at least two tuning (i.e., frequency control) signals applied to inputs thereof from a control unit. The control unit receives a frequency difference signal which is a measure of the difference between the laser output signal and a reference signal, and uses that frequency difference signal together with present values to derive the tuning signals. The control unit stores a variety of different values for the preset values so that the laser output signal can be tuned to a variety of different desired frequencies. To avoid undesired frequency jumps of the laser output signal due to mode hopping, the control unit assures that the tuning signal will have a predetermined disproportional relationship. The control unit is able to correct the preset values (and the values used therefor) on the basis of the frequency difference signal.