Patent ID: 6931031

Claim:
An optical system, comprising: a dual wavelength optical waveguide laser comprising a first optical waveguide containing an optical gain medium, the first optical waveguide including a first grating section in which a first optical waveguide grating device is provided, the first optical waveguide grating device having a periodic refractive index variation which gives the first optical waveguide grating device a spectral profile having two passbands located within a stopband, the first grating section being birefringent, the first optical waveguide grating device defining at least one distributed optical waveguide laser cavity, the first optical waveguide being optically coupled at one end to a second optical waveguide including a second grating section in which a second optical waveguide grating device is provided, the first optical waveguide grating device, in combination with the first birefringent grating section, giving rise to two potential lasing modes of a first polarization state and two potential lasing modes of a second polarization state orthogonal to the first polarization state, each potential lasing mode being of a different wavelength, the second optical waveguide grating device selecting one of the potential lasing modes of the first polarization state and one of the potential lasing modes of the second polarization state for oscillation; and a pump laser, operable to generate a pump optical signal, in optical communication with the first optical waveguide.