Raman effects in a highly nonlinear holey fiber: amplification and modulation

We experimentally demonstrate that a short length of highly nonlinear holey fiber (HF) can be used for strong L+-band (1610~1640nm) Raman amplification and ultra-fast signal modulation. We use a pure silica HF with an effective area of just 2.85µm2 at 1550nm, which yields an effective nonlinearity ~15 times higher than in conventional silica dispersion-shifted fiber. Using a 75m length of this fiber, we obtained internal Raman gains of over 42dB and a noise figure of ~6dB under a forward single pump scheme, and the Raman gain coefficient was experimentally estimated to be 7.6 x 10-14 m/W. Also, an 11dB signal extinction ratio in a Raman induced all-optical modulation experiment was achieved using the same fiber