Systems and methods for manufacturing waveguide cells
Systems for the manufacturing of waveguide cells in accordance with various embodiments can be configured and implemented in many different ways. In many embodiments, various deposition mechanisms are used to deposit layer(s) of optical recording material onto a transparent substrate. A second transparent substrate can be provided, and the three layers can be laminated to form a waveguide cell. Suitable optical recording material can vary widely depending on the given application. In some embodiments, the optical recording material deposited has a similar composition throughout the layer. In a number of embodiments, the optical recording material spatially varies in composition, allowing for the formation of optical elements with varying characteristics. Regardless of the composition of the optical recording material, any method of placing or depositing the optical recording material onto a substrate can be utilized.
1. A method for manufacturing waveguide cells, the method comprising;
providing a first substrate;
determining a predefined grating characteristic;
depositing a layer of optical recording material onto the first substrate using at least one deposition head; and
holographically exposing the layer of optical recording material on the first substrate, wherein the optical recording material deposited over the grating region is formulated to achieve the predefined grating characteristic after holographic exposure.
2. The method of claim 1 , further comprising:
providing a second substrate;
placing the second substrate onto the deposited layer of optical recording material; and
laminating the first substrate, the layer of optical recording material, and the second substrate.
3. The method of claim 1 , wherein depositing the layer of optical recording material comprises:
providing a first mixture of optical recording material;
providing a second mixture of optical recording material; and
depositing the first and second mixtures of optical recording material onto the first substrate in a predetermined pattern using the at least one deposition head.
4. The method of claim 3 , wherein:
the first mixture of optical recording material comprises a first bead; and
the second mixture of optical recording material comprises a second bead that is a different size from the first bead.
5. The method of claim 3 , wherein the first mixture of optical recording material has a different percentage by weight of liquid crystals than the second mixture of optical recording material.
6. The method of claim 3 , further comprising defining a grating region and a nongrating region on the first substrate, wherein:
the first mixture of optical recording material comprises a liquid crystal and a monomer;
the second mixture of optical recording material comprises a monomer; and
depositing the first and second mixtures of optical recording material onto the first substrate in the predetermined pattern comprises:
depositing the first mixture of optical recording material over the grating region; and
depositing the second mixture of optical recording material over the nongrating region.
7. The method of claim 3 , wherein the first mixture of optical recording material is a polymer dispersed liquid crystal mixture comprising:
a monomer;
a liquid crystal;
a photoinitiator dye; and
a coinitiator.
8. The method of claim 7 , wherein the polymer dispersed liquid crystal mixture comprises an additive selected from the group consisting of: a photoinitiator, nano particles, low-functionality monomers, additives for reducing switching voltage, additives for reducing switching time, additives for increasing refractive index modulation, and additives for reducing haze.
9. The method of claim 1 , wherein the at least one deposition head comprises at least one inkjet print head.
10. The method of claim 9 , wherein depositing the layer of optical recording material comprises:
providing a first mixture of optical recording material;
providing a second mixture of optical recording material;
printing a first dot of the first mixture of optical recording material using the at least one inkjet print head; and
printing a second dot of the second mixture of optical recording material adjacent to the first dot using the at least one inkjet print head.
11. The method of claim 9 , wherein:
the at least one inkjet print head comprises a first inkjet print head and a second inkjet print head; and
depositing the layer of optical recording material comprises:
providing a first mixture of optical recording material;
providing a second mixture of optical recording material;
printing the first mixture of optical recording material onto the first substrate using the first inkjet print head; and
printing the second mixture of optical recording material onto the first substrate using the second inkjet print head.
12. The method of claim 1 , wherein the predefined grating characteristic comprises a characteristic selected from the group consisting of: refractive index modulation, refractive index, birefringence, liquid crystal director alignment, and grating layer thickness.
13. The method of claim 1 , wherein the predefined grating characteristic comprises a spatial variation of a characteristic selected from the group consisting of: refractive index modulation, refractive index, birefringence, liquid crystal director alignment, and grating layer thickness.
14. The method of claim 1 , wherein the predefined grating characteristic results in a grating after exposure, the grating having a spatially varying diffraction efficiency.