Systems and methods of making polymeric optical layers for optical layering
The present disclosure relates to systems and methods of making polymeric optical layers for optical layering applications. In an aspect, a waveguide device for a head mounted display is provided. The waveguide device may include a waveguide die having a first refractive index range and a polymeric optical layer. The polymeric optical layer may include a second refractive index range that is different from the first refractive index range and a thiol-containing polymer. For example, the thiol-containing polymer may include thiourethane. In some embodiments, the thiol-containing polymer may be formed from a monomer mixture including a thiol-containing compound and an isocyanate. For example, the thiol-containing compound may include 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (MDTODT) and/or the isocyanate may include m-xylylene diisocyanate (XDI). In some embodiments, the monomer mixture may include a second thiol-containing compound, such as, for example, 1,3-benzene dithiol (1,3-BDT).
1 . A waveguide device for a head mounted display, the waveguide device comprising:
a waveguide die, wherein the waveguide die comprises a first refractive index range; and
a polymeric optical layer, wherein the polymeric optical layer comprises:
a second refractive index range that is different from the first refractive index range; and
a thiol-containing polymer.
2 . The waveguide device of claim 1 , wherein the thiol-containing polymer comprises thiourethane.
3 . The waveguide device of claim 1 , wherein the thiol-containing polymer is formed from a monomer mixture comprising:
a thiol-containing compound; and
an isocyanate.
4 . The waveguide device of claim 3 , wherein the thiol-containing compound comprises 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (MDTODT).
5 . The waveguide device of claim 3 , wherein the isocyanate comprises m-xylylene diisocyanate (XDI).
6 . The waveguide device of claim 3 , wherein the monomer mixture further comprises a second thiol-containing compound.
7 . The waveguide device of claim 6 , wherein the second thiol-containing compound comprises 1,3-benzene dithiol (1,3-BDT).
8 . The waveguide device of claim 4 , wherein the polymeric optical layer comprises a varying index optical layer having a refractive index gradient across a thickness of the polymeric optical layer.
9 . The waveguide device of claim 1 , wherein the polymeric optical layer comprises a plurality of polymeric optical layers, wherein each of the plurality of polymeric optical layers is a discretized layer having a different refractive index than an adjacent polymeric optical layer.
10 . A method for forming a waveguide device, the method comprising:
segmenting a wafer to obtain a waveguide die;
dispensing a monomer mixture onto the waveguide die, wherein the monomer mixture comprises:
a thiol-containing compound; and
an isocyanate; and
curing monomer mixture to form a polymeric optical layer on the waveguide.
11 . The method of claim 10 , wherein the thiol-containing compound comprises MDTODT.
12 . The method of claim 10 , wherein the isocyanate comprises XDI.
13 . The method of claim 10 , wherein the method further comprising adding a second thiol-containing compound to the monomer mixture prior to dispensing the monomer mixture onto the waveguide die.
14 . The method of claim 10 , wherein segmenting the wafer comprises dicing the wafer to obtain the waveguide die.
15 . The method of claim 10 , wherein the monomer mixture further comprises a catalyst.
16 . The method of claim 15 , wherein the catalyst comprises dibutyltin dichloride (DBTDC).
17 . The method of claim 10 further comprising installing the waveguide device in a head-mounted display.
18 . The method of claim 10 further comprising applying a planarization stamp to the dispensed monomer mixture before curing to set a thickness of the polymeric optical layer.
19 . A polymeric optical layer for optical applications, wherein the polymeric optical layer comprises a thiol-containing polymer, wherein the thiol-containing polymer is formed from a monomer mixture comprising:
a thiol-containing compound, wherein the thiol-containing compound comprises at least one of:
4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (MDTODT);
bis(2-mercaptoethyl)sulfide (BMES); or
1,3-benzene dithiol (1,3-BDT); and
an isocyanate, wherein the isocyanate comprises at least one of:
m-xylylene diisocyanate (XDI); or
tetravinyl silane (TVSi),
wherein the polymeric optical layer comprises:
a thickness from 200 to 500 μm;
a refractive index from 1.4-1.7 across the thickness of the polymeric optical layer; and
an absorption, α, that is less than or equal to 0.02 cm −1 .
20 . The polymeric optical layer of claim 19 , wherein the polymeric optical layer further comprises:
a density, ρ, in a range from 0.1 to 2 g/cm 3 ; and
a bidirectional scattering distribution function (BSDF) that is less than or equal to 0.001 sr −1 .