An Orthogonal-Polarization Dual-Wavelength Fiber Laser with Stable Output

A new orthogonal-polarization dual-wavelength fiber laser by fabricating a uniform FBG and a chirped FBG in a polarization-maintaining erbium-doped fiber (PM-EDF) is proposed and demonstrated. The wavelength space is 0.18 nm and the optical signal-to-noise ratio is greater than 50 dB with pump power of 246-mW. Chirped FBG is used to make the reflectivity wavelengths match between two PM-FBGs much easier. Since both EDF and FBGs are polarization-maintaining without splices and the two wavelengths operate with two orthogonal polarizations, the maximum amplitude variation and wavelength shifts for both lasing wavelength with 3-min intervals over a period of six hours were less than 0.2 dB and 0.005 nm, which shows stable dual-wavelength output.