Optical coupling device with a holographic diffraction structure

A method for making an optical system, comprising at least:

• making a first optical guide device configured to emit and/or receive a first light beam according to a first direction,
• making a second optical guide device on the substrate over which the first optical guide device is arranged, the second optical guide device being configured to receive and/or emit the first light beam according to a second direction;
• making an optical coupling device including the following steps:
• depositing a holographic material layer over at least one region of the substrate at which a holographic diffraction structure is intended to be made;
• emitting a first write light beam by the first optical guide device according to the first direction, and a second write light beam according to a third direction which is not parallel to the first direction and which meets the first write light beam in a first region of the holographic diffraction structure which is representative of the interferences produced between the first and second write light beams;
• emitting a third write optical beam by the second optical guide device parallel to the second direction, and a fourth write light beam, corresponding to a light beam conjugated with the second write light beam, according to a fourth direction opposite to the third direction and which meets the third write light beam in a second region of the holographic diffraction structure which is representative of the interferences produced between the third and fourth write light beams.