Stable 120-mW green output tunable over 2 THz by a second-harmonic generation process in a KTP crystal at room...

We report on 120-mW directly measured cw power at 532 nm from a tunable alpha -distributed-feedback laser diode near 1.064 microm frequency doubled in a KTP crystal operating room temperature inside a ring cavity. Our experimental setup allows us to scan frequencies up to 2 THz in the green-light domain and thus is extremely useful for iodine spectroscopy. We show good agreement between experimental results and theoretical predictions for the second-harmonic generation process.