Multi-watt 589nm fiber laser source

We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichio-metric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938mn fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to > 15W using cladding pumped Nd3+ fiber amplifiers. The fiber amplifiers operate at 938nm and minimize amplified spontaneous emission at 1088nm by employing a specialty fiber design, which maximizes the core size relative to the cladding diameter. This design allows the 3-level laser system to operate at high inversion, thus making it competitive with the 1088nm 4-level laser transition. At 15W, the 938nm laser has an M-2 of 1.1 and good polarization (correctable with a quarter and half wave plate to > 15: 1). The 1583nm fiber laser consists of a Koheras 1583nm fiber DFB laser that is pre-amplified to 100mW, phase modulated and then amplified to 14W in a commercial IPG fiber amplifier. As a part of our research efforts we are also investigating pulsed laser formats and power scaling of the 589nm system. We will discuss the fiber laser design and operation as well as our results in power scaling at 589nm.