Provided are a method for generating polarization orthogonal dual-
wavelength optical signals with a large tuning range for a
frequency interval, and a device thereof. The method comprises: two parallel double-parallel Mach-zehnder modulators forming an integrated modulator, a Sagnac ring being embedded with a narrow-band
fiber bragg
grating, under a large-
signal modulation mode, one double-parallel Mach-zehnder modulator generating carrier
waves and a high-order
nonlinear optical edge band, and the other double-parallel Mach-zehnder modulator performing non-
microwave local oscillation modulation, two output optical signals being polarized orthogonal coupled, and the polarized orthogonal coupled two paths of optical signals projecting to a same direction, restraining optical carrier, to obtain a high-order dual-
wavelength optical edge band, inputting the Sagnac ring which is embedded with the
fiber bragg
grating and a polarization coupler, using characteristics of reflection of a
fiber bragg
grating narrow band and transmission of a
wide band, to realize
wavelength separation, using a characteristic of polarization selection of the polarization coupler, to realize polarization orthogonal
coupling of dual-wavelength optical signals, and on the output end of the Sagnac ring, the polarization orthogonal dual-wavelength optical signals are obtained. The method is advantaged by high
clock multiplier factor and large tuning range.