A high-efficiency tunable cw Raman oscillator

Abstract

Continuously tunable cw Raman oscillation has been achieved in the visible by pumping a single‐mode fused silica fiber with several lines from an argon ion laser. The 100‐m‐long fiber has a core diameter of 3.3 μm and a loss of 17 dB/km at 5145 Å. Threshold was achieved with ∼1.0 W of pump power in the fiber. With 4 W of 5145‐Å power coupled into the fiber, the Raman oscillator was prism tuned over 80 Å. Typical linewidths were ∼2 Å. At 5280 Å, net input to output power conversion efficiencies of ∼9% and pump depletion of over 80% have been achieved. The simplicity, efficiency, and broadband tunability of fiber Raman oscillators both in the visible and in the near infrared make them potential rivals to other coherent sources of tunable radiation, such as dye lasers and parametric oscillators.