Method and apparatus for maintaining alignment of a laser diode with an optical fiber

Abstract

A method and apparatus for maintaining an alignment of a laser diode with an optical fiber is disclosed. A mounting plate is made of a first material, and mounted on the mounting plate is a first substrate made of a second material. A semiconductor laser, with a light emitting side, is mounted on the first substrate. Separated from the first substrate by a predetermined distance is a second substrate made of a third material, and mounted on the second substrate is an optical fiber. The optical fiber is mounted, such that, the optical fiber is adjacent to and aligned with the light emitting side of the semiconductor laser. The first, second, and third materials making up the mounting plate, the first substrate, and the second substrate respectively, facilitate maintenance of the alignment between the optical fiber and the light emitting side of the semiconductor laser.

1. An apparatus comprising:
 a mounting plate comprising a first material;  
 a first substrate mounted on the mounting plate, the first substrate comprising a second material;  
 a semiconductor laser mounted on the first substrate, the semiconductor laser having a light emitting side;  
 a second substrate mounted on the mounting plate and separated from the first substrate by a predetermined distance, the second substrate material including a shelf formation above the mounting plate, the second substrate comprising a third material; and  
 an optical fiber mounted on the second substrate, the optical fiber being adjacent to and aligned with the light emitting side of the laser, wherein the first, second and third materials being complementary in thermal characteristic to facilitate maintenance of the alignment between the optical fiber and the light emitting side of the laser.  
 
     
     
       2. The apparatus of  claim 1 , wherein the first material is a conductor of heat. 
     
     
       3. The apparatus of  claim 1 , wherein the first material comprises at least one of a CuW alloy, a CuMo alloy, and pure Mo. 
     
     
       4. The apparatus of  claim 1 , wherein the first material comprises a thermal conductivity value:
 the thermal conductivity value being at least 160 W/m 2 K/m; and  
 the thermal conductivity value being no more than 185 W/m 2 K/m.  
 
     
     
       5. The apparatus of  claim 1 , wherein the first material comprises a coefficient of thermal expansion (CTE) value, and the CTE being linear and measured at 20° C.:
 the CTE value being at least 6.1 μm/m° C.; and  
 the CTE value being no more than 7.36 μm/m° C.  
 
     
     
       6. The apparatus of  claim 1 , wherein the first material comprises a thermal conductivity value:
 the thermal conductivity value being at least 140 W/m 2 K/m; and  
 the thermal conductivity value being no more than 175 W/m 2 K/m.  
 
     
     
       7. The apparatus of  claim 1 , wherein the first material comprises a CTE value, and the CTE value being linear and measured at 20° C.:
 the CTE value being at least 6.5 μm/m° C./; and  
 the CTE value being no more than 7.2 μm/m° C.  
 
     
     
       8. The apparatus of  claim 1 , wherein the first material comprises a thermal conductivity value of 138 W/m 2 K/m. 
     
     
       9. The apparatus of  claim 1 , wherein the first material comprises a CTE value of 5.35 μm/m° C., and the CTE value being linear and measured at 20° C. 
     
     
       10. The apparatus of  claim 1 , wherein the second material is a conductor of heat. 
     
     
       11. The apparatus of  claim 1 , wherein the second material comprises at least one of an AIN and BeO. 
     
     
       12. The apparatus of  claim 1 , wherein the second material comprises a thermal conductivity value:
 the thermal conductivity value being at least 90 W/m 2 K/m; and  
 the thermal conductivity value being no more than 170 W/m 2 K/m.  
 
     
     
       13. The apparatus of  claim 1 , wherein the second material comprises a CTE value, and the CTE value being linear and measured at 20° C.:
 the CTE value being at least 4.2 μm/m° C.; and  
 the CTE value being no more than 4.3 μm/m° C.  
 
     
     
       14. The apparatus of  claim 1 , wherein the second material comprises a thermal conductivity value of 248 W/m 2 K/m. 
     
     
       15. The apparatus of  claim 1 , wherein the second material comprises a CTE value of 6.4 μm/m° C., and the CTE being linear and measured at 20° C. 
     
     
       16. The apparatus of  claim 1 , wherein the third material is a thermally insulating material. 
     
     
       17. The apparatus of  claim 1 , wherein the third material is an aluminum oxide. 
     
     
       18. The apparatus of  claim 1 , wherein the third material comprises a thermal conductivity value of no more than 28 W/m 2 K/m. 
     
     
       19. The apparatus of  claim 1 , wherein the third material comprises a CTE value of no more than 7.4 μm/m° C., and the CTE being linear and measured at 250° C. 
     
     
       20. The apparatus of  claim 1 , wherein the apparatus is an optical networking module. 
     
     
       21. The apparatus of  claim 1  wherein the optical fiber is mounted upon the shelf formation of the second substrate material. 
     
     
       22. An apparatus comprising:
 a mounting plate, the mounting plate comprising a first material;  
 a first substrate mounted on the mounting plate, the first substrate comprising a second material; an semiconductor laser mounted on the first substrate, the semiconductor laser having a light emitting side;  
 a second substrate mounted on the mounting plate substantially in contact with the first substrate, the second substrate material including a shelf formation above the mounting plate, the second substrate comprising a third material; and  
 an optical fiber mounted on the second substrate, the optical fiber being adjacent to and aligned with the light emitting side the laser.  
 
     
     
       23. The apparatus of  claim 22 , wherein the first material comprises at least one of a CuW alloy, a CuMo alloy, and pure Mo. 
     
     
       24. The apparatus of  claim 22 , wherein the first material comprises a thermal conductivity value:
 the thermal conductivity value being at least 160 W/m 2 K/m; and  
 the thermal conductivity value being no more than 185 W/m 2 K/m.  
 
     
     
       25. The apparatus of  claim 22 , wherein the first material comprises a coefficient of thermal expansion (CTE) value, and the CTE being linear and measured at 20° C.:
 the CTE value being at least 6.1 μm/m° C.; and  
 the CTE value being no more than 7.36 μm/m° C.  
 
     
     
       26. The apparatus of  claim 22 , wherein the first material comprises a thermal conductivity value:
 the thermal conductivity value being at least 140 W/m 2 K/m; and  
 the thermal conductivity value being no more than 175 W/m 2 K/m.  
 
     
     
       27. The apparatus of  claim 22 , wherein the first material comprises a CTE value, and the CTE value being linear and measured at 20° C.:
 the CTE value being at least 6.5 μm/m° C./; and  
 the CTE value being no more than 7.2 μm/m° C.  
 
     
     
       28. The apparatus of  claim 22 , wherein the first material comprises a thermal conductivity value of 138 W/m 2 K/m. 
     
     
       29. The apparatus of  claim 22 , wherein the first material comprises a CTE value of 5.35 μm/m° C., and the CTE value being linear and measured at 20° C. 
     
     
       30. The apparatus of  claim 22 , wherein the second material comprises at least one of an AIN and BeO. 
     
     
       31. The apparatus of  claim 22 , wherein the second material comprises a thermal conductivity value:
 the thermal conductivity value being at least 90 W/m 2 K/m; and  
 the thermal conductivity value being no more than 170 W/m 2 K/m.  
 
     
     
       32. The apparatus of  claim 22 , wherein the second material comprises a CTE value, and the CTE value being linear and measured at 20° C.:
 the CTE value being at least 4.2 μm/m° C.; and  
 the CTE value being no more than 4.3 μm/m° C.  
 
     
     
       33. The apparatus of  claim 22 , wherein the second material comprises a thermal conductivity value of 248 Wm 2 K/m. 
     
     
       34. The apparatus of  claim 22 , wherein the second material comprises a CTE value of 6.4 μm/m° C., and the CTE being linear and measured at 20° C. 
     
     
       35. The apparatus of  claim 22 , wherein the third material is an aluminum oxide. 
     
     
       36. The apparatus of  claim 22 , wherein the third material comprises a thermal conductivity value of no more than 28 W/m 2 K/m. 
     
     
       37. The apparatus of  claim 22 , wherein the third material comprises a CTE value of no more than 7.4 μm/m° C., and the CTE being linear and measured at 250° C. 
     
     
       38. The apparatus of  claim 22  wherein the apparatus is an optical networking module. 
     
     
       39. The apparatus of  claim 22  Wherein the optical fiber is mounted upon the shelf formation of the second substrate material. 
     
     
       40. An apparatus, comprising:
   a mounting plate, the mounting plate comprising a first material;        a first substrate mounted on the mounting plate, the first substrate comprising a second material;        a laser device mounted on the first substrate, the laser device having a light emitting side;        a second substrate mounted on the mounting plate, the second substrate material including a shelf formation above the mounting plate, the second substrate comprising a third material; and        an optical fiber mounted on the second substrate, the optical fiber being aligned with the light emitting side of the laser device.     
     
     
       41. The apparatus of  claim 40 , wherein said laser device comprises a semiconductor laser. 
     
     
       42. The apparatus of  claim 40 , wherein said second substrate is substantially in contact with said first substrate. 
     
     
       43. The apparatus of  claim 40 , wherein said first and second substrates are separated by a predetermined distance. 
     
     
       44. The apparatus of  claim 40 , wherein said first material comprises a conductor of heat. 
     
     
       45. The apparatus of  claim 40 , wherein the first, second and third materials are complementary in thermal characteristic to facilitate maintenance of the alignment between the optical fiber and the light emitting side of the laser device. 
     
     
       46. The apparatus of  claim 40 , wherein said second material comprises a conductor of heat. 
     
     
       47. The apparatus of  claim 40 , wherein said optical fiber is mounted on said shelf. 
     
     
       48. The apparatus of  claim 40 , wherein said optical fiber is mounted adjacent to said light emitting side of said laser device.