A Tunable $S$ -Plus $L$ -Band Continuous-Wave Single-Longitudinal-Mode Fiber-Optical Parametric Oscillator

We demonstrate an all-fiber continuous-wave single-longitudinal-mode fiber-optical parametric oscillator. The output tuning range extends from 1487 to 1541 nm and from 1570 to 1630 nm, which covers the
S
- and
L
-bands. Single-longitudinal-mode oscillation with a side-mode suppression ratio greater than 43 dB is achieved while the linewidth of the output is 1.5 kHz. This scheme has the potential to be a useful source in wavelength-division-multiplexing networks and optical communications in the nonconventional wavelength bands.