A wavelength sensor by optical directional coupler

A wavelength sensor based on the optical directional coupler is proposed in the paper. The finite-difference time-domain (FDTD) method is used to calculate of the light intensity propagating thorough the structure, and to find the appropriate dimensions of the structure. A particular dimension of the device has shown the coupling efficiency varying linearly with wavelengths. Thus, the structure could be employed as the wavelength sensor for the wavelength in a range between 1.2 /spl mu/m and 1.6 /spl mu/m.