High speed optical sub-assembly with ceramic carrier

Abstract

A multilayer ceramic carrier for an optical element includes a terraced cavity for retaining a vertically receiving or vertically emitting optical element. The multilayer ceramic carrier includes conductive traces interposed between the ceramic layers and which extend into the terraced cavity along the trenches formed in the cavity. A vertical cavity surface emitting laser or vertically receiving optical element is wire bonded to the conductive traces which extend into the cavity. In one embodiment, the terraced cavity of the multilayer ceramic carrier includes a VCSEL and photodetector therein, the photodetector capable of monitoring the output optical power of the VCSEL. The method for forming the multilayer ceramic carrier includes forming a plurality of layers of ceramic tape, joining the layers, then co-firing the stacked layers. The multilayer ceramic carrier is joined to a plastic optical housing which includes an aperture for securing an optical fiber. The fiber launch direction is generally orthogonal to the optical surface of the vertically emitting or vertically receiving optical element secured within the ceramic carrier. The optical subassembly comprising the plastic optical housing and ceramic carrier is mounted on the surface of a printed circuit board or adjacent the edge of a printed circuit board, such that the light emitted or detected by the optical element, preferably travels along a fiber launch direction parallel to the surface of the printed circuit board. The optical assembly may be joined to the printed circuit board using various connectors capable of carrying an electrical signal.

1 - 43 . (canceled)  
   
   
       44 . An optical element comprising a carrier containing an optical source therein and adapted to be joined to an optical housing, said carrier including a top surface and an opposed bottom surface being generally parallel to said top surface, a terraced cavity extending down from said top surface and including interior sidewalls and a base surface, said terraced cavity including: terraces formed at different heights on opposed interior sidewalls; said optical source disposed on said base surface, capable of emitting light along a direction generally orthogonal to said top surface, and wire bonded to a conductive trace formed along a terrace of said terraced cavity; and a photodetector disposed therein and being capable of detecting light emitted by said optical source.  
   
   
       45 . The optical element as in  claim 44 , wherein said carrier is formed of one of a dielectric material and a polymeric material.  
   
   
       46 . The optical element as in  claim 44 , wherein said carrier is formed of ceramic.  
   
   
       47 . The optical element as in  claim 44 , wherein said optical source comprises a VCSEL.  
   
   
       48 . A multilayer ceramic carrier formed of a plurality of stacked ceramic layers and including a photodetector therein, said multilayer ceramic carrier including a bottom surface and an opposed top surface being generally parallel to said bottom surface, a terraced cavity extending down from said top surface and including interior sidewalls and a base surface, said photodetector disposed on said base surface and oriented to detect light directed into said terraced cavity and generally perpendicular to said base surface, said terraced cavity including at least one terrace formed on at least one of said interior sidewalls, at least one of said plurality of ceramic layers including conductive traces thereon, such that said multilayer ceramic carrier therefore includes conductive traces interposed between at least a pair of adjacent stacked ceramic layers, at least a part of one of said conductive traces extending along a terrace of said terraced cavity and terminating within said terraced cavity.  
   
   
       49 . The multilayer ceramic carrier as in  claim 48 , wherein said photodetector is wire bonded to said part of one of said conductive traces which extends along said terrace of said terraced cavity and terminates within said terraced cavity.  
   
   
       50 . The multilayer ceramic carrier as in  claim 48 , further comprising a further electronic device disposed within said terraced cavity, said further electronic device being electrically coupled to said photodetector and wire bonded to at least one of said conductive traces.  
   
   
       51 . The multilayer ceramic carrier as in  claim 50 , wherein said further electronic device comprises one of a transimpedance amplifier and a limiting amplifier integrated circuit.  
   
   
       52 . The multilayer ceramic carrier as in  claim 48 , in which said photodetector includes an absorbing surface and further comprising an optical housing attached to said ceramic carrier, said optical housing retaining an optical fiber therein, said optical fiber oriented generally perpendicularly to said absorbing surface.  
   
   
       53 . The multilayer ceramic carrier as in  claim 48 , wherein said photodetector comprises a p-i-n photodiode.  
   
   
       54 - 135 . (canceled)