Multi-wavelength fiber optical parametric oscillator with ultra-narrow wavelength spacing.

We propose a novel multi-wavelength fiber optical parametric oscillator (MW-FOPO) based on a ring cavity. A highly nonlinear fiber and a Mach-Zehnder interferometer formed by two 3-dB optical couplers are used as the gain medium and the comb filter, respectively. Multi-wavelength lasing of the MW-FOPO with an ultra-narrow wavelength spacing of about 0.08 nm is achieved. The output spectrum of the MW-FOPO covers a wavelength regime from 1510 nm to 1615 nm (for lasing wavelengths with the power that exceeds -60 dBm). The stability of the MW-FOPO is discussed and experimentally demonstrated. A comparison of the output spectra between the MW-FOPO and the multi-wavelength Erbium-doped fiber laser is also presented.