Indirect monitoring of semiconductor light source within a photonic package

Abstract

A photonic package includes a housing having a semiconductor light source disposed within the housing. The semiconductor light source has a first output and a second output. A reflective surface is disposed inside the housing to reflect the second output from the semiconductor light source. A photodetector is also disposed within the housing and is adapted to indirectly receive the second output of the semiconductor light source reflected off the reflective surface. As a result, interior surface of a housing of an optical transponder may be utilized to provide reflected light to a photodetector to monitor the semiconductor light source.

1. A photonic package comprising:
 a housing; 
 a semiconductor light source disposed within the housing, the semiconductor light source having a first output and a second output; 
 a first reflective surface disposed inside the housing selected from one of a side wall of the housing and an interior surface of a cover of the housing to reflect said second output; 
 a second reflective surface to deflect the second output to the first reflective surface; and 
 a photodetector disposed within the housing adapted to indirectly receive said second output of the semiconductor light source reflected off said first reflective surface. 
 
     
     
       2. The photonic package of  claim 1 , wherein the photonic package comprises an optical transponder. 
     
     
       3. The photonic package of  claim 1 , wherein the first reflective surface comprises an exterior surface of an elevated substrate angularly disposed relative to the second output, to reflect said second output to said photodetector. 
     
     
       4. The photonic package of  claim 1 , wherein the second reflective surface comprises a reflective mirror to angularly reflect the second output. 
     
     
       5. The photonic package of  claim 4 , wherein the first reflective surface is optically coupled to said reflective mirror to further reflect the second output to said photodetector. 
     
     
       6. The photonic package of  claim 1 , wherein the first output is provided from a front facet of the semiconductor light source. 
     
     
       7. The photonic package of  claim 1 , wherein the second output is provided from a back facet of the semiconductor light source. 
     
     
       8. The photonic package of  claim 1 , wherein the photodetector comprises a photodiode. 
     
     
       9. The photonic package of  claim 8 , wherein the photodiode comprises a p-i-n junction photodiode. 
     
     
       10. The photonic package of  claim 1 , wherein said first reflective surface comprises a reflective coating. 
     
     
       11. The photonic package of  claim 10 , wherein the reflective coating comprises paint having a pigment of titanium dioxide. 
     
     
       12. A method for forming a photonic package comprising:
 providing a semiconductor light source to provide a first and a second output; 
 providing a first reflective surface to reflect the second output of the semiconductor light source, wherein said providing of a first reflective surface comprises providing a reflective interior surface to a housing of the photonic package; 
 providing a second reflective surface and disposing said second reflective surface in a manner such that said second reflective surface reflects said second output of the semiconductor light source to said reflective interior surface of the housing, for reflection to said a photodetector; and 
 adapting a said photodetector to indirectly receive the second output of the semiconductor light source reflected from the interior surface. 
 
     
     
       13. The method of  claim 12 , wherein said providing of a reflective surface comprises providing a substrate having an angular exterior surface, and the method further comprises disposing said substrate in a manner such that said angular exterior surface of the substrate reflects said second output of the semiconductor light source to said photodetector. 
     
     
       14. The method of  claim 12 , wherein said providing of a second reflective surface comprises of providing a mirror and disposing said mirror in a manner such that said mirror reflects said second output of the semiconductor light source to said reflective interior surface of the house housing, for reflection to said photodetector. 
     
     
       15. The photonic package of  claim 14 , wherein said at least one of said first and said second reflective surfaces comprises a mirror. 
     
     
       16. A photonic package comprising:
 a housing; 
 a semiconductor light source disposed within the housing, the semiconductor light source having a first output and a second output; 
 a first reflective surface disposed inside the housing to reflect said second output; 
 a second reflective surface to deflect the second output to the first reflective surface, at least one of said first and said second reflective surfaces is selected from one of a side wall of the housing and an interior surface of a cover of the housing; and 
 a photodetector disposed within the housing adapted to indirectly receive said second output of the semiconductor light source reflected off said first reflective surface. 
 
     
     
       17. A method of monitoring a semiconductor light source substantially enclosed in a housing, the method comprising:
 generating a light output signal from the semiconductor light source;   deflecting the light output signal from a back facet of the semiconductor light source toward an interior surface of the housing;   reflecting the light output signal from the interior surface toward a photodetector; and   receiving, at the photodetector, the light output signal reflected from the interior surface.   
     
     
       18. The method of claim 17, wherein said deflecting comprises deflecting the light output signal toward an interior surface selected from one of a side wall of the housing or an interior surface of a cover of the housing. 
     
     
       19. The method of claim 18, wherein the selected interior surface comprises a reflective surface. 
     
     
       20. The method of claim 17, wherein said deflecting comprises deflecting the light output signal toward an interior surface having a reflective surface. 
     
     
       21. The method of claim 20, wherein the reflective surface comprises a silicon mirror. 
     
     
       22. The method of claim 20, wherein the reflective surface comprises a reflective sheet. 
     
     
       23. The method of claim 20, wherein the reflective surface comprises a dielectric coating surface. 
     
     
       24. The method of claim 17, further comprising:
 generating an electrical signal at the photodetector in response to said receiving the light output signal.   
     
     
       25. The method of claim 24, further comprising:
 comparing, by a processor, the electrical signal to characterization data to facilitate calibration of the received light output signal by the photodetector.   
     
     
       26. The method of claim 25, further comprising:
 facilitating, by the processor, an adjustment of a bias voltage of the photodetector in response to said comparing.