Optical structures including nanocrystals

Abstract

An optical structure can include a nanocrystal on a surface of an optical waveguide in a manner to couple the nanocrystal to the optical field of light propagating through the optical waveguide to generate an emission from the nanocrystal.

1 . An optical structure comprising a layer of nanocrystals on a surface of an optical waveguide, the nanocrystal being positioned to be optically coupled to an optical field propagating through the optical waveguide, the layer having a thickness selected to minimize nanocrystal light self-absorption. 
     
     
         2 . The optical structure of  claim 1 , wherein the waveguide is an optical fiber. 
     
     
         3 . The optical structure of  claim 1 , wherein the waveguide is a planar waveguide. 
     
     
         4 . The optical structure of  claim 1 , wherein the nanocrystal is a semiconductor nanocrystal. 
     
     
         5 . The optical structure of  claim 2 , wherein the optical fiber has a cladding layer that allows light to escape at a selected amount along the length of the fiber. 
     
     
         6 . The optical structure of  claim 4 , wherein the semiconductor nanocrystal includes a core including a first semiconductor material. 
     
     
         7 . The optical structure of  claim 6 , wherein the semiconductor nanocrystal includes an overcoating on a surface of the core including a second semiconductor material. 
     
     
         8 . The optical structure of  claim 1 , further comprising a plurality of nanocrystals distributed at a first portion of the surface. 
     
     
         9 . The optical structure of  claim 8 , further comprising a plurality of nanocrystals distributed at a second portion of the surface. 
     
     
         10 . The optical structure of  claim 9 , wherein the plurality of nanocrystals distributed at the first portion of the surface has a composition different from the plurality of nanocrystals distributed at the first portion of the surface. 
     
     
         11 . A light emitting structure comprising:
 a light source arranged to introduce light including an excitation wavelength into an optical waveguide; and   a layer nanocrystals on a surface of the optical waveguide, the nanocrystal being positioned to be optically coupled to an optical field propagating through the optical waveguide and capable of absorbing the excitation wavelength of light and emitting an emission wavelength of light, the layer having a thickness selected to minimize nanocrystal light self-absorption.   
     
     
         12 . The light emitting structure of  claim 11 , wherein the waveguide is an optical fiber. 
     
     
         13 . The light emitting structure of  claim 11 , wherein the waveguide is a planar waveguide. 
     
     
         14 . The light emitting structure of  claim 11 , wherein the nanocrystal is a semiconductor nanocrystal. 
     
     
         15 . The light emitting structure of  claim 12 , wherein the optical fiber has a cladding layer that allows light to escape at a selected amount along the length of the fiber. 
     
     
         16 . The light emitting structure of  claim 14 , wherein the semiconductor nanocrystal includes a core including a first semiconductor material. 
     
     
         17 . The light emitting structure of  claim 16 , wherein the semiconductor nanocrystal includes an overcoating on a surface of the core including a second semiconductor material. 
     
     
         18 . The light emitting structure of  claim 11 , further comprising a plurality of nanocrystals distributed at a first portion of the surface. 
     
     
         19 . The light emitting structure of  claim 18 , further comprising a plurality of nanocrystals distributed at a second portion of the surface. 
     
     
         20 . The light emitting structure of  claim 19 , wherein the plurality of nanocrystals distributed at the first portion of the surface has a composition different from the plurality of nanocrystals distributed at the first portion of the surface. 
     
     
         21 .- 32 . (canceled) 
     
     
         33 . An optical structure comprising a layer of nanocrystals on a surface of an optical waveguide, the nanocrystals being positioned to be optically coupled to an optical field propagating through the optical waveguide, the layer having a thickness selected to minimize nanocrystal light self-absorption, a plurality of nanocrystals distributed at a first portion of the surface, and a plurality of nanocrystals distributed at a second portion of the surface. 
     
     
         34 . The optical structure of  claim 33 , wherein the plurality of nanocrystals distributed at the first portion of the surface has a composition different from the plurality of nanocrystals distributed at the first portion of the surface. 
     
     
         35 . A light emitting structure comprising:
 a light source arranged to introduce light including an excitation wavelength into an optical waveguide; and   a layer of nanocrystals on a surface of the optical waveguide, the nanocrystal being positioned to be optically coupled to an optical field propagating through the optical waveguide and capable of absorbing the excitation wavelength of light and emitting an emission wavelength of light, the layer having a thickness selected to minimize nanocrystal light self-absorption, a plurality of nanocrystals distributed at a first portion of the surface, and a plurality of nanocrystals distributed at a second portion of the surface.   
     
     
         36 . The light emitting structure of  claim 35 , wherein the plurality of nanocrystals distributed at the first portion of the surface has a composition different from the plurality of nanocrystals distributed at the first portion of the surface. 
     
     
         37 . The optical structure of  claim 1 , wherein the mixture of different nanocrystals comprises a combination of nanocrystals for generating a white light spectrum. 
     
     
         38 . The light emitting structure of  claim 11 , wherein the mixture of different nanocrystals comprises a combination of nanocrystals for generating a white light spectrum. 
     
     
         39 . The optical structure of  claim 33 , wherein the mixture of different nanocrystals comprises a combination of nanocrystals for generating a white light spectrum. 
     
     
         40 . The light emitting structure of  claim 35 , wherein the mixture of different nanocrystals comprises a combination of nanocrystals for generating a white light spectrum.