SOA-based quad-wavelength ring laser

A quad-wavelength fiber ring laser using a semiconductor optical amplifier (SOA) as a gain medium and an array waveguide grating (AWG) as a selective wavelength filter is proposed and demonstrated. The quad-wavelength fiber ring laser is capable of generating four laser wavelengths at 1531.0 nm, 1533.3 nm, 1535.7 nm, and 1538.0 nm with a peak power at –20 dBm and a channel spacing of 0.24 nm (300 GHz) corresponding to the channel spacing of the selected AWG ports. The quad-wavelength ring laser shows stable operation over time with negligible fluctuations in the peak power of the lasing wavelengths. The separation of the two lasing wavelengths can be tuned over several nanometers by changing the ports of the AWG. The proposed laser configuration has the advantage of stable quad-wavelength output at room temperature as well as a simple and compact design with many potential DWDM and sensor applications.