A method to form a three-dimensional photonic crystal template with a gradient structure involves irradiating a photoresist composition of a thickness of at least 15 μm from at least four laser beams to yield a periodic patterned with a percolating matrix of mass in constructive volumes of a cured photoresist composition and destructive volumes of voids free of condensed matter where the proportion of constructive volume displays a gradient from the irradiated surface to the substrate after development. For a given light intensity, photoinitiator concentration in the photoresist composition, and a given thickness, by irradiating for a relatively short period, a three-dimensional photonic crystal template displaying a gradient having greater constructive volume proximal the air interface forms and a relatively long irradiation period results in a gradient having greater constructive volume proximal the substrate.

A method for producing a volume hologram with at least one first area in a first color and at least one second area in a second color includes, providing a volume hologram layer made of a photopolymer; arranging a master with a surface structure on the volume hologram layer; exposing the master using coherent light, wherein light which is incident on at least one first partial area of the surface of the master is diffracted or reflected in the direction of the at least one first area of the volume hologram layer and light which is incident on at least one second partial area of the surface of the master is diffracted or reflected in the direction of the at least one second area of the volume hologram, and wherein the light diffracted or reflected by the first and second partial areas differs in at least one optical property.

A method to form a three-dimensional photonic crystal template with a gradient structure involves irradiating a photoresist composition of a thickness of at least 15 μm from at least four laser beams to yield a periodic patterned with a percolating matrix of mass in constructive volumes of a cured photoresist composition and destructive volumes of voids free of condensed matter where the proportion of constructive volume displays a gradient from the irradiated surface to the substrate after development. For a given light intensity, photoinitiator concentration in the photoresist composition, and a given thickness, by irradiating for a relatively short period, a three-dimensional photonic crystal template displaying a gradient having greater constructive volume proximal the air interface forms and a relatively long irradiation period results in a gradient having greater constructive volume proximal the substrate.

A method for producing a volume hologram with at least one first area in a first color and at least one second area in a second color includes, providing a volume hologram layer made of a photopolymer; arranging a master with a surface structure on the volume hologram layer; exposing the master using coherent light, wherein light which is incident on at least one first partial area of the surface of the master is diffracted or reflected in the direction of the at least one first area of the volume hologram layer and light which is incident on at least one second partial area of the surface of the master is diffracted or reflected in the direction of the at least one second area of the volume hologram, and wherein the light diffracted or reflected by the first and second partial areas differs in at least one optical property.

Provided is a method and apparatus for generating a binary hologram. More particularly, provided is a method and apparatus that may decrease or, alternatively, minimize quality degradation of a binary hologram by employing a silhouette mask of a target object to reduce or, alternatively, minimize background noise occurring around the target object to be reproduced when generating the binary hologram.

Provided is a method and apparatus for generating a binary hologram. More particularly, provided is a method and apparatus that may decrease or, alternatively, minimize quality degradation of a binary hologram by employing a silhouette mask of a target object to reduce or, alternatively, minimize background noise occurring around the target object to be reproduced when generating the binary hologram.

A method for integrating a synthetic hologram in an image of a scene, including: forming, from a first image of the scene, a first matrix including pixels of two shades according to the gray level of the corresponding pixel of the first image, and a second matrix, image of the gray level difference between the corresponding pixels of the first image and of the first matrix; forming a third matrix based on a second image; forming a fourth matrix having each pixel including a central area with a surface area determined by the corresponding element of the second matrix and off-centered in the pixel according to the corresponding pixel of the third matrix; and performing a lithography of an opaque layer at the surface of a plate according to the pattern defined by the fourth pixel matrix.

Provided are a method and apparatus for optimizing a holographic display. The holographic display back-propagates target field data including generating a predicted hologram by a plurality of planes in a depth direction to a complex plane of a space light modulator (SLM), converts the predicted hologram into a binary hologram, generates predicted field data by forward-propagating the binary hologram to a reproduction plane through an optical system simulation model, calculates a loss function between the predicted field data and the target field data, generates a new predicted hologram for the predicted field data by using a stochastic gradient descent (SGD) method to reduce a value of the loss function, and repeats the generation of the new predicted hologram until the value of the loss function is less than a predefined threshold.