Backplane, printed wiring board, and/or multi-chip module-level optical interconnect layer having embedded air-gap technologies and methods of fabrication

Abstract

Optical interconnect layers and methods of fabrication thereof are described. In addition, the optical interconnect layers integrated into devices such as backplane (BP), printed wiring board (PWB), and multi-chip module (MCM) level devices are described. A representative optical interconnect layer includes a first cladding layer, a second cladding layer, one or more waveguides having a waveguide core and an air-gap cladding layer engaging a portion of waveguide core, wherein the first cladding layer and the second cladding layer engage the waveguide.

Therefore, having thus described the invention, at least the following is claimed:  
     
         1 . A device, comprising: 
 an optical interconnect layer including: 
 a first cladding layer;  
 a second cladding layer;  
 at least one waveguide having a waveguide core; and  
 an air-gap cladding layer engaging a portion of waveguide core, wherein the first cladding layer and the second cladding layer engage the waveguide.  
   
     
     
         2 . The device of  claim 1 , wherein the device is chosen from a backplane, a printed wiring board, and a multi-chip module.  
     
     
         3 . The device of  claim 1 , further comprising, 
 at least one coupler element disposed adjacent to the waveguide core.    
     
     
         4 . The device of  claim 1 , further comprising: 
 a first sacrificial layer that can be removed to form the air-gap cladding layer.    
     
     
         5 . The device of  claim 4 , wherein the first sacrificial layer is chosen from polynorborenes, polyoxymethylene, polycarbonates, polyethers, and polyesters.  
     
     
         6 . An optical interconnect layer, comprising: 
 a first cladding layer;    a second cladding layer;    at least one optical dielectric waveguide having a waveguide core; and    an air-gap cladding layer engaging a portion of waveguide core, wherein the first cladding layer and the second cladding layer engage the waveguide.    
     
     
         7 . The optical interconnect layer of  claim 6 , further comprising a substrate made of a dielectric material.  
     
     
         8 . The optical interconnect layer of  claim 6 , wherein the first cladding layer is chosen from polyimides, polynorborenes, epoxides, polyarylenes, ethers, and parylenes.  
     
     
         9 . The optical interconnect layer of  claim 6 , wherein the second cladding layer is chosen from polyimides, polynorborenes, epoxides, polyarylenes, ethers, and parylenes.  
     
     
         10 . The optical interconnect layer of  claim 6 , wherein the air-gap cladding layer has a height from about 1 to about 100 micrometers.  
     
     
         11 . A method for monolithically fabricating an optical interconnect layer comprising: 
 (a) disposing at least one waveguide core on a portion of a first cladding layer;    (b) disposing a sacrificial layer onto at least one portion of the first cladding layer and a portion of the waveguide core;    (c) disposing an second cladding layer onto the first cladding layer and the sacrificial layer; and    (d) removing the sacrificial layer to define an air-gap cladding layer within the first cladding layer and the second cladding layer, and wherein the air-gap cladding engages a portion of the waveguide core.    
     
     
         12 . The method of  claim 11 , further including: 
 forming a volume grating layer adjacent to the waveguide core after (a) and before (b).    
     
     
         13 . The method of  claim 12 , further including: 
 forming at least one volume grating coupler element.    
     
     
         14 . The method of  claim 11 , further including: 
 integrating the optical interconnect layer into a device chosen from a backplane, a printed wiring board, and a multi-chip module.    
     
     
         15 . A method for fabricating a device having an optical interconnect layer comprising: 
 disposing at least one waveguide core on a portion of a first cladding layer;    forming at least one volume grating coupler element adjacent the waveguide core;    disposing a sacrificial layer onto at least one portion of the first cladding layer and a portion of the waveguide core;    disposing a second cladding layer onto the first cladding layer and the sacrificial layer;    removing the sacrificial layer to define an air-gap cladding layer within the first cladding layer and the second cladding layer, and wherein the air-gap cladding engages a portion of the waveguide core; and    attaching the optical interconnect layer to a device chosen from a backplane, printed wiring board, and a multi-chip module.    
     
     
         16 . The method of  claim 15 , wherein the sacrificial layer is chosen from polynorborenes, polyoxymethylene, polycarbonates, polyethers, and polyesters.  
     
     
         17 . The method of  claim 15 , wherein the waveguide core includes a transparent dielectric material.  
     
     
         18 . The method of  claim 15 , wherein the first cladding layer is chosen from polyimides, polynorborenes, epoxides, polyarylenes, ethers, and parylenes.  
     
     
         19 . The method of  claim 15 , wherein the second cladding layer is chosen from polyimides, polynorborenes, epoxides, polyarylenes, ethers, and parylenes.