Method and apparatus for fabrication of large three-dimensional single colloidal crystals for bragg diffraction of infrared light
A three-dimensional Bragg grating may include a single colloidal crystal that includes a plurality of repeated layers of material having different refractive indexes. A sample cell for producing a volume Bragg grating may include an internal shape that forms at least one capillary cell having a flat surface and rounded edges. A method of producing a three-dimensional Bragg grating may include: suspending insoluble particles in a host fluid to form a suspension; and exposing the suspension to a sustained microgravity environment.
1 . A three-dimensional Bragg grating, comprising:
a single colloidal crystal that:
includes periodic particles and interstitial material, and
due to having been grown in a micro-gravity environment:
is topological defect free; and
lacks a high-density glass phase.
2 . The three-dimensional Bragg grating of claim 1 , wherein the periodic particles are formed from fluorescent poly ethyl methacrylate.
3 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal is a Face Centered Cubic crystal.
4 . The three-dimensional Bragg grating of claim 1 , wherein the three-dimensional Bragg grating is a volume Bragg grating, and has a volume on the order of millimeters cubed.
5 . The three-dimensional Bragg grating of claim 1 , wherein the periodic particles are micron-sized spheres.
6 . The three-dimensional Bragg grating of claim 5 , wherein the micron-sized spheres have a particle size variation of less than 5%.
7 . The three-dimensional Bragg grating of claim 5 , further comprising:
at least one stabilization layer or coating configured to stabilize the micron-sized spheres against aggregation.
8 . The three-dimensional Bragg grating of claim 7 , wherein the at least one stabilization layer or coating is formed from a graft copolymer including an insoluble anchor group and soluble side chains.
9 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal lacks dendritic growth instabilities.
10 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal has a lateral dimension of about 100 microns and a volume of about 20 mm{circumflex over ( )}3.
11 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal has a volume with:
a first dimension on the order of tens of millimeters;
a second dimension on the order of millimeters; and
a third dimension on the order of tenths of millimeters.
12 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal has dimensions of 27 mm×1.5 mm×0.15 mm.
13 . The three-dimensional Bragg grating of claim 1 , wherein the interstitial material includes air, such that the single colloidal crystal is a direct lattice.
14 . The three-dimensional Bragg grating of claim 1 , wherein the periodic particles are configured to be dissolvable such that the interstitial material is configured to form a back-filled or inverse lattice.
15 . The three-dimensional Bragg grating of claim 14 , wherein the interstitial material includes TiO 2 .
16 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal has been solidified or crosslinked with a solvent.
17 . The three-dimensional Bragg grating of claim 16 , wherein the single colloidal crystal further includes a photocross-linker incorporated into constituent polymer chains.
18 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal is configured to withstand about 6g's of gravity acceleration.
19 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal is a photonic crystal.
20 . The three-dimensional Bragg grating of claim 1 , wherein the single colloidal crystal has a bandgap in the infrared range.