Patent ID: 7177072

Claim:
An optical wavelength converting device having a periodic domain inversion structure, in which a periodic electrode is formed on one surface of a single-polarized ferroelectric substance having nonlinear optical effects, and an electric field is applied across the ferroelectric substance by the utilization of the periodic electrode in order to set regions of the ferroelectric substance, which stand facing the periodic electrode, as local area limited domain inversion regions, the optical wavelength converting device produced by a process comprising the steps of: i) forming a first resist layer and a second resist layer in this order on the one surface of the ferroelectric substance, the first resist layer being removable by etching, the second resist layer being photosensitive and having properties such that, when light is irradiated to the second resist layer, only exposed areas of the second resist layer or only unexposed areas of the second resist layer become soluble in a developing solvent, ii) exposing the second resist layer to near-field light in a periodic pattern with means, which receives exposure light and produces the near-field light in the periodic pattern, iii) developing the second resist layer, which has been exposed to the near-field light, to form a periodic pattern in the second resist layer, iv) etching the first resist layer by utilizing the periodic pattern of the second resist layer as an etching mask to form a periodic pattern composed of the first resist layer and the second resist layer, and v) forming the periodic electrode on the one surface of the ferroelectric substance by utilizing the periodic pattern, which is composed of the first resist layer and the second resist layer, as a mask, the periodic electrode being formed at positions corresponding to opening areas of the mask.