Patent ID: 11899316
Assignee: NAGAOKA UNIVERSITY OF TECHNOLOGY
Field: Optics (Instruments)
Classification: CPC G  C | IPC G

Claim 12:
13. A method for producing a terahertz wave control element, comprising the step of:
(I) preparing a first substrate capable of transmitting a terahertz wave, the first substrate having one surface provided with a first electrode capable of transmitting a terahertz wave;
(II) preparing a first liquid crystal aligning agent comprising a photoreactive polymer having a photoreactive side chain that causes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization;
(III) applying the first liquid crystal aligning agent on the first electrode of the first substrate, to form a first liquid crystal alignment film;
(IV) (i) a 1st light irradiation step: irradiating the first liquid crystal alignment film with a first polarized light through a photomask having a 1st region with a first width that transmits the first polarized light and a second region with a second width that does not transmit the first polarized light alternately in a predetermined cycle, to cause the reaction in the photoreactive polymer in a first portion corresponding to the first region of the first liquid crystal alignment film; and
(ii) a 2nd light irradiation step: disposing the photomask so that a second portion different from the first portion in the 1st light irradiation step is formed as a region capable of transmitting a second polarized light orthogonal to the first polarized light, and irradiating the first liquid crystal alignment film with the second polarized light through the photomask to cause the reaction in the photoreactive polymer in the second portion of the first liquid crystal alignment film;
(V) performing heat treatment on the substrate obtained after the 1st and 2nd light irradiation steps, to obtain a first flat plate;
(I′) preparing a second substrate capable of transmitting a terahertz wave, the second substrate having one surface provided with a second electrode capable of transmitting a terahertz wave;
(II′) preparing a second liquid crystal aligning agent comprising a photoreactive polymer having a photoreactive side chain that causes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization;
(III′) applying the second liquid crystal aligning agent on the second electrode of the second substrate, to form a second liquid crystal alignment film;
(IV′) (i′) a 1′st light irradiation step: irradiating the second liquid crystal alignment film with a first polarized light through the photomask, to cause the reaction in the photoreactive polymer in a 1′st portion corresponding to the first region of the second liquid crystal alignment film; and
(ii) a 2′nd light irradiation step: disposing the photomask so that a 2′nd portion different from the 1′st portion in the 1′st light irradiation step is formed as a region capable of transmitting a second polarized light orthogonal to the first polarized light, and irradiating the second liquid crystal alignment film with the second polarized light through the photomask to cause the reaction in the photoreactive polymer in the 2′nd portion of the second liquid crystal alignment film;
(V′) performing heat treatment on the substrate obtained after the 1′st and 2′nd light irradiation steps, to obtain a second flat plate;
(VI) locating the first flat plate and the second flat plate in parallel with a predetermined distance therebetween so that the first and second liquid crystal alignment films are opposite to each other, the 1st portion of the first liquid crystal alignment film and the 1′st portion of the second liquid crystal alignment film are opposite to each other, and the 2nd portion of the first liquid crystal alignment film and the 2′nd portion of the second liquid crystal alignment film are opposite to each other, to provide a space between the first flat plate and the second flat plate; and
(VII) filling the space with a liquid crystal;, thereby to obtain the terahertz wave control element.