A method and system for converting one frequency into another include a MOPA configuration radiating a light at a first frequency which is coupled into a frequency conversion unit. Further included are a control unit operative to monitor the other frequency and a pump unit operative to vary its output power provided that the monitored frequency does not substantially match a reference value stored in the control unit. The output power of the pump unit varies while the master oscillator scans its cavity in search for the desired resonant frequency.