公开(公告)号：US20220268983A1

公开(公告)日：2022-08-25

申请号：US17628998

申请日：2020-08-27

Applicant: University of Southampton

Inventor： Masaaki SAKAKURA ,  Lei WANG ,  Peter KAZANSKY ,  Yanhao YU ,  Yuhao LEI

IPC: G02B5/30 ,  C03C23/00 ,  G11B7/0045

Abstract: A method of fabricating an optical element comprises: providing a substrate (1, 50) of a transparent material in which is to be formed a plurality of birefringent nanostructures spaced apart in plane substantially parallel to a surface of the substrate in a first direction (2) by a distance X and in a second direction (3) by a distance Y; generating from the output of a source (20) of femtosecond laser pulses a laser beam group comprising a plurality of focused seeding beams (44) having a circular polarisation and spaced apart along a line by the distance X and a focused writing beam (26) having a non-circular polarisation and spaced apart from one of the seeding beams by the distance Y or the distance X; directing the laser beam group onto the surface of the substrate at a first position and applying one or more femtosecond laser pulses from each beam to corresponding volumes in the substrate; repeatedly translating the laser beam group relative to the substrate parallel to the line of seeding beams and along the first direction by the distance X to a next position and applying one or more femtosecond laser pulses from each beam, in order to deliver a plurality of femtosecond laser pulses from the seeding beams to each corresponding volume to create substantially optically isotropic nanostructures in the corresponding volumes; translating the laser beam group relative to the substrate along the second direction by the distance Y and repeating the repeated translation and application of the femtosecond laser pulses along the first direction; wherein the relative translation of the laser beam group and the substrate aligns the writing beam with successive corresponding volumes in which substantially optically isotropic nanostructures have been created, so that the one or more femtosecond laser pulses applied from the writing beam transform the optically isotropic nanostructure in each corresponding volume into an optically isotropic nanostructure with optical birefringence.

公开(公告)号：US20210265798A1

公开(公告)日：2021-08-26

申请号：US17181472

申请日：2021-02-22

Applicant: University of Southampton

Inventor： Masaaki SAKAKURA ,  Yanhao YU ,  Peter KAZANSKY ,  Lei WANG

IPC: H01S3/00 ,  G02B27/09 ,  G02B5/30

Abstract: A method of delivering optical pulses to a substrate comprises directing a focused beam from a source of optical pulses along a propagation direction onto a substrate; moving the substrate relative to the beam in a plane substantially orthogonal to the propagation direction and continuously along a first direction that includes spaced apart row locations on the substrate, and delivering a plurality of optical pulses from source as the beam reaches each row location; and between delivering the optical pulses at consecutive row locations, moving the beam relative to the substrate in one or more successive discrete movements along a second direction in the plane orthogonal to the first direction, to direct the beam to one or more spaced apart column locations on the substrate, and delivering a plurality of optical pulses from the source at each column location.

公开(公告)号：US20210265797A1

公开(公告)日：2021-08-26

申请号：US17181414

申请日：2021-02-22

Applicant: University of Southampton

Inventor： Masaaki SAKAKURA ,  Yanhao YU ,  Peter KAZANSKY ,  Lei WANG

IPC: H01S3/00 ,  B23K26/0622

Abstract: A method of delivering optical energy to a substrate comprises applying a temporal group of optical pulses to a region of the substrate, wherein the temporal group comprises twenty or fewer pulses of a femtosecond pulse duration, arranged as a first subgroup of pulses comprising up to three pulses followed by a second subgroup of pulses comprising the remaining pulses in the temporal group; and wherein energies of the pulses are controlled such that pulses in the first subgroup have a first energy per pulse and pulses in a second subgroup of pulses have a second energy per pulse which is less than the first energy.