Polymer aerogel optical waveguide
A head-up display, such as found in smart glasses, may include a light source configured to project light for display. A heads-up display may include a polymer aerogel optical waveguide configured to receive the light from the light source, guide the received light to an area in front of an eye of a user, and project the light to the eye of the user. The polymer aerogel optical waveguide can include a core portion made from a glass having a relatively high index of refraction and a cladding portion made from a polymer aerogel having a relatively low index of refraction so that light is guided in the core portion by total internal reflection at an interface between the core portion and the cladding portion.
1 . A heads-up display comprising:
a light source configured to project light for display; and
an optical waveguide including:
a core portion including a glass layer having a first index-of-refraction;
an in-coupling grating configured to couple light from the light source into the core portion; and
a cladding portion including a polymer aerogel layer having a second index-of-refraction, the glass layer and the polymer aerogel layer having an interface configured to provide total internal reflection so that the coupled light is guided in the core portion between the in-coupling grating and an out-coupling grating, the out-coupling grating configured to couple the guided light out of the core portion and towards an eye of a user, wherein the in-coupling grating and the out-coupling grating define gaps in a surface of the glass layer of the core portion, the gaps being filled with the polymer aerogel layer of the cladding portion, wherein the polymer aerogel layer has an adhesive property such that the polymer aerogel layer is adhered to the surface of the glass layer, without an intervening adhesive layer.
2 . The heads-up display according to claim 1 , wherein the light source and the optical waveguide are included in smart glasses.
3 . The heads-up display according to claim 1 , wherein the polymer aerogel layer is substantially transparent at visible wavelengths of the optical spectrum.
4 . The heads-up display according to claim 3 , wherein the polymer aerogel layer is colorless.
5 . The heads-up display according to claim 1 , wherein the polymer aerogel layer is at least 50 microns thick.
6 . The heads-up display according to claim 1 , wherein the second index-of-refraction (n aerogel ) of the polymer aerogel layer is in a range between 1.1 and 1.3, inclusive (1.1≤n aerogel ≤1.3).
7 . The heads-up display according to claim 6 , wherein the first index-of-refraction (n glass ) of the glass layer is greater than or equal to 1.5 (n glass ≥1.5).
8 . The heads-up display according to claim 1 , wherein the polymer aerogel layer is fabricated from a sol-gel including a poly(meth)acrylate polymer, a polycarbonate polymer, a polyester polymer, a cyclic olefin polymer (COP), a cyclic olefin copolymer (COC), or a silicone polymer.
9 . A head-worn device comprising:
a light source configured to project light; and
a lens including:
an optical waveguide configured to receive the light from the light source, the optical waveguide including:
a core portion including a glass layer having a first index-of-refraction;
an in-coupling grating configured to couple the light from the light source into the core portion of the optical waveguide; and
a cladding portion including a polymer aerogel layer having a second index-of-refraction, the glass layer and the polymer aerogel layer having an interface configured to provide total internal reflection so that the coupled light is guided by the optical waveguide in the core portion between the in-coupling grating and an out-coupling grating, the out-coupling grating configured to couple the guided light out of the core portion of the optical waveguide and towards an eye of a user, wherein the in-coupling grating and the out-coupling grating define gaps in a surface of the glass layer of the core portion, the gaps being filled with the polymer aerogel layer of the cladding portion, wherein the polymer aerogel layer has an adhesive property such that the polymer aerogel layer is adhered to the surface of the glass layer without an intervening adhesive layer.
10 . The head-worn device according to claim 9 , wherein the polymer aerogel layer is substantially transparent at visible wavelengths of the optical spectrum.
11 . The head-worn device according to claim 10 , wherein the polymer aerogel layer is colorless.
12 . The head-worn device according to claim 9 , wherein: the head-worn device is smart glasses.
13 . The head-worn device according to claim 9 , wherein the polymer aerogel layer is at least 50 microns thick.
14 . The head-worn device according to claim 9 , wherein the second index-of-refraction (n aerogel ) of the polymer aerogel layer is in a range between 1.1 and 1.3, inclusive (1.1≤n aerogel ≤1.3).
15 . The head-worn device according to claim 14 , wherein the first index-of-refraction (n glass ) of the glass layer is greater than or equal to 1.5 (n glass ≥1.5).
16 . The head-worn device according to claim 9 , wherein the polymer aerogel layer is fabricated from a sol-gel including a poly(meth)acrylate polymer, a polycarbonate polymer, a polyester polymer, a cyclic olefin polymer (COP), a cyclic olefin copolymer (COC), or a silicone polymer.