A process for the preparation of a frequency doubling structure in an optically not - linear medium, and apparatus for the frequency doubling

摘要

A frequency doubling structure composed of an alternatingly poled NLO polymer is incorporated into an optically non-linear (NLO) polymeric material. This structure is made by forming a layer of a first NLO polymer, partially removing it by etching after it has been poled with the aid of a first electric field or not, such that a grating structure is formed composed of etched grooves in the polymer, and applying a layer of a second NLO polymer, such that the etched grooves are backfilled, after which the resulting alternating structure of the two NLO polymers is subjected either to a second electric field oppositely directed to the first one, or in the case of poling of the first polymer not yet having taken place, to two oppositely directed electric fields in succession. The second electric field is applied at a temperature which will not affect the poling of one NLO polymer effected by the first electric field. Further, a frequency doubler comprising an alternating structure of oppositely poled NLO polymer is provided.