Gradient refractive index lenses and methods of fabricating the same
AssigneeThe Florida International University Board of Trustees
InventorsOmena Okpowe, Nezih Pala, Chunlei Wang
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Abstract
Gradient refractive index lenses (GRI-Ls) and methods of fabricating the same are provided. GRI-Ls can be fabricated by stereolithography (SLA) and/or photo-assisted, thermal-assisted, and/or other laser-based curing from at least two precursors with a preset refractive index gradation along the planar axis. These lenses are self-focusing lenses and may be convergent or divergent for decreasing and increasing refractive indices from the center, respectively. Rather than a gradation in lens thickness from the center, the GRI-Ls can have a gradation of composition from the center.
Claims20
A method of fabricating a gradient refractive index lens (GRI-L), the method comprising:
- preparing a sol gel precursor comprising a first material;
- preparing a resin sludge comprising a second material and a polymer material, the second material being different from the first material, and a refractive index of the first material being different from a refractive index of the second material;
- performing a three-dimensional (3D) printing process in a vat platform using the resin sludge to give a green body;
- performing a calcination process on the green body at a first temperature high enough to eliminate the polymer material, to give a calcinated body;
- flooding the sol gel precursor into the vat platform with the calcinated body to give an intermediate lens body, the flooding of the sol gel being performed in such a manner so as to allow for control of concentration of the sol gel precursor along a vertical axis of the intermediate lens body and a horizontal axis of the intermediate lens body;
- performing a densification step on the intermediate lens body at a second temperature to give the GRI-L.
A method of fabricating a gradient refractive index lens (GRI-L), the method comprising:
- preparing a sol gel precursor comprising a first material;
- preparing a resin sludge comprising a second material and a polymer material, the second material being different from the first material, and a refractive index of the first material being different from a refractive index of the second material;
- performing a three-dimensional (3D) printing process in a vat platform using the resin sludge to give a green body;
- adding a dopant to the green body to give a doped green body;
- performing a calcination process on the doped green body at a first temperature high enough to eliminate the polymer material, to give a calcinated body;
- flooding the sol gel precursor into the vat platform with the calcinated body to give an intermediate lens body, the flooding of the sol gel being performed in such a manner so as to allow for control of concentration of the sol gel precursor along a vertical axis of the intermediate lens body and a horizontal axis of the intermediate lens body;
- performing a densification step on the intermediate lens body at a second temperature to give the GRI-L.
A method of fabricating a gradient refractive index lens (GRI-L), the method comprising:
- preparing a sol gel precursor comprising a first material;
- preparing a resin sludge comprising a second material and a polymer material, the second material being different from the first material, and a refractive index of the first material being different from a refractive index of the second material;
- thickening the resin sludge with fumed silica nanoparticles;
- performing a three-dimensional (3D) printing process in a vat platform using the thickened resin sludge to give a green body;
- performing a calcination process on the green body at a first temperature high enough to eliminate the polymer material, to give a calcinated body;
- flooding the sol gel precursor into the vat platform with the calcinated body to give an intermediate lens body, the flooding of the sol gel being performed in such a manner so as to allow for control of concentration of the sol gel precursor along a vertical axis of the intermediate lens body and a horizontal axis of the intermediate lens body;
- performing a densification step on the intermediate lens body at a second temperature to give the GRI-L,
- the GRI-L being planar,
- a thickness of the GRI-L being constant from the center of the GRI-L to the edge of the GRI-L,
- the first material being a ceramic material,
- the second temperature being below a softening temperature of silica,
- the second material being a ceramic material,
- the first temperature being below the softening temperature of silica,
- the method further comprising adding a dopant either before or after performing the calcination process, and
- the thickness of the GRI-L being in a range of from 1 millimeter (mm) to 12 centimeters (cm).
Dependencies are inferred from the claim text.