Organic solid crystal—method and structure
A method of forming an organic solid crystal (OSC) thin film includes forming a layer of a non-volatile medium material over a surface of a mold, forming a layer of a molecular feedstock over a surface of the non-volatile medium material, the molecular feedstock including an organic solid crystal precursor, forming crystal nuclei from the organic solid crystal precursor, and growing the crystal nuclei to form the organic solid crystal thin film. An organic solid crystal (OSC) thin film may include a biaxially-oriented organic solid crystal layer having mutually orthogonal refractive indices, n 1 ≠n 2 ≠n 3 .
1. A method comprising:
forming a layer of a non-volatile medium material over a surface of a mold;
forming a layer of a molecular feedstock over a surface of the non-volatile medium material, the molecular feedstock comprising an organic solid crystal precursor;
forming crystal nuclei from the organic solid crystal precursor; and
growing the crystal nuclei to form a biaxially-oriented organic solid crystal thin film having mutually orthogonal refractive indices, n 1 ≠n 2 ≠n 3 , wherein in-plane refractive indices (n 2 , n 3 ) of the biaxially-oriented organic solid crystal thin film are related according to |n 2 −n 3 |>0.05.
2. The method of claim 1 , wherein the non-volatile medium material comprises a liquid selected from the group consisting of silicone oil, paraffin oil, a fluorinated polymer, a polyolefin and polyethylene glycol.
3. The method of claim 1 , wherein the molecular feedstock comprises a process enhancer selected from the group consisting of polymers, oligomers, and small molecules, the process enhancer having a melting onset temperature of at least approximately 20° C. less than a melting onset temperature of the organic solid crystal precursor.
4. The method of claim 1 , wherein the organic solid crystal precursor comprises a crystallizable organic molecule.
5. The method of claim 1 , wherein forming the layer of molecular feedstock comprises injecting the molecular feedstock into the mold.
6. The method of claim 1 , wherein the crystal nuclei are formed within a nucleation region of the layer of the molecular feedstock.
7. The method of claim 6 , wherein forming the crystal nuclei comprises heating the layer of the molecular feedstock to a temperature less than a melting onset temperature of the organic solid crystal precursor within the nucleation region.
8. The method of claim 6 , wherein forming the crystal nuclei comprises melting selected crystal nuclei outside of the nucleation region.
9. The method of claim 1 , further comprising separating the organic solid crystal thin film from the surface of the non-volatile medium material.
10. A thin film comprising a biaxially-oriented organic solid crystal layer having mutually orthogonal refractive indices, n 1 ≠n 2 ≠n 3 , wherein in-plane refractive indices (n 2 , n 3 ) of the biaxially-oriented organic solid crystal layer are related according to |n 2 −n 3 |>0.05.
11. The thin film of claim 10 , wherein the biaxially-oriented organic solid crystal layer comprises a single crystal.
12. The thin film of claim 10 , wherein in-plane refractive indices (n 2 , n 3 ) of the biaxially-oriented organic solid crystal layer are related according to (n 2 +n 3 )/2>1.5.
13. The thin film of claim 10 , wherein an out-of-plane refractive index (n 1 ) of the biaxially-oriented organic solid crystal layer is related to in-plane refractive indices (n 2 , n 3 ) of the biaxially-oriented organic solid crystal layer according to
n
1
=
1
2
π
∫
0
2
π
(
n
2
sin
φ
)
2
+
(
n
3
cos
φ
)
2
d
φ
.
14. The thin film of claim 10 , wherein a major surface of the thin film comprises a periodic array of structures.
15. An optical element comprising the thin film of claim 10 , wherein the optical element comprises a passive component selected from the group consisting of a waveguide substrate, a grating, a microlens, a prismatic lens, a Fresnel lens, a reflective polarizer, a Pancharatnam-Berry phase (PBP) lens, an ophthalmic lens, and a photonic integrated circuit.
16. An optical element comprising the thin film of claim 10 , wherein the optical element comprises an active component selected from the group consisting of a phase modulator, a photonic integrated circuit, a polarization modulator, and an amplitude modulator.
17. A method comprising:
providing a layer of a non-volatile medium material;
forming a layer of a molecular feedstock over a surface of the non-volatile medium material, the molecular feedstock comprising an organic solid crystal precursor;
forming crystal nuclei from the organic solid crystal precursor within a nucleation region of the layer of the molecular feedstock; and
growing the crystal nuclei to form a biaxially-oriented organic solid crystal thin film having mutually orthogonal refractive indices, n 1 ≠n 2 ≠n 3 , wherein in-plane refractive indices (n 2 , n 3 ) of the biaxially-oriented organic solid crystal thin film are related according to |n 2 −n 3 |>0.05.
18. The method of claim 17 , wherein the organic solid crystal precursor comprises a crystallizable organic molecule.
19. The method of claim 17 , wherein forming the crystal nuclei comprises heating the layer of the molecular feedstock to a temperature less than a melting onset temperature of the organic solid crystal precursor within the nucleation region.