Patent ID: 8582611

Claim:
A method for operating a pulsed MOPA including a polarization-maintaining fiber-amplifier having one or more fiber-amplifier stages, the method comprising: generating a plane-polarized pulse to be amplified by the fiber-amplifier, the pulse having a fundamental frequency; dividing the pulse into first and second plane-polarized pulse-components having polarization orientations at 90-degrees to each other; amplifying the first and second plane-polarized pulse-components in the polarization-maintaining fiber-amplifier thereby providing first and second amplified plane-polarized pulse-components; directing the first and second amplified plane-polarized pulse-components along respectively first and second separate optical paths; and frequency-doubling the first amplified plane-polarized pulse-component in the first optical path, thereby generating a first frequency-doubled plane-polarized pulse-component having a frequency which is the second harmonic of the fundamental frequency.