System and method for bi-directional optical communication using stacked emitters and detectors

Abstract

Disclosed is a bi-directional optical link and method to facilitate bi-directional optical communications with a single optical fiber. Briefly described, the bi-directional optical link comprises a thin film detector having an upper surface facing a predetermined direction to receive incident light. Also, the link includes a thin film emitter stacked over the upper surface and oriented to direct a beam of light toward the predetermined direction. The thin film detector is relatively wide and flat, where the thin film emitter can be placed on the thin film detector while occluding only a portion of the thin film detector. Thus, the thin film detector can receive incident light from a single optical fiber facing the emitter/detector from the predetermined direction while at the same time emitting a beam of light into the same single optical fiber.

1 . A bi-directional optical link, comprising: 
 a thin film detector having an upper surface facing a predetermined direction to receive incident light; and    a thin film emitter stacked over the upper surface and oriented to direct a beam of light toward the predetermined direction.    
   
   
       2 . The link of  claim 1 , wherein the thin film emitter is a vertical cavity surface emitting laser.  
   
   
       3 . The link of  claim 1 , wherein the thin film emitter is a light emitting diode.  
   
   
       4 . The link of  claim 1 , wherein the thin film emitter further comprises a pair of electrical connectors for electrically coupling the thin film emitter to a circuit.  
   
   
       5 . The link of  claim 1 , wherein the thin film detector is an inverted metal-semiconductor-metal photodetector.  
   
   
       6 . A method establishing a bi-directional communications link, comprising the steps of: 
 positioning a thin film detector having an upper surface so as to face a predetermined direction to receive incident light;    stacking a thin film emitter over the upper surface; and    orienting the thin film emitter to direct a beam of light toward the predetermined direction.    
   
   
       7 . The method of  claim 6 , wherein the step of stacking a thin film emitter over the upper surface further comprises the step of stacking a vertical cavity surface emitting laser over the upper surface.  
   
   
       8 . The method of  claim 6 , wherein the step of stacking a thin film emitter over the upper surface further comprises the step of stacking a light emitting diode.  
   
   
       9 . The method of  claim 6 , further comprising the step of providing a pair of electrical connectors for electrically coupling the thin film emitter to a circuit.  
   
   
       10 . The method of  claim 6 , wherein the step of positioning a thin film detector further comprises the step of positioning an inverted metal-semiconductor-metal photodetector.  
   
   
       11 . The method of  claim 6 , wherein the thin film detector and the thin film emitter comprise a substrate-removed semiconductor material.  
   
   
       12 . The method of  claim 6 , wherein the step of stacking comprises stacking to occlude a portion of the thin film detector.  
   
   
       13 . The method of  claim 6 , wherein the step of orienting comprises orienting the thin film emitter to emit the beam of light while the detector receives the incident light.