Scalable thermally efficient pump diode systems

Abstract

Scalable, thermally efficient pump diode systems. These systems may include an arrangement of pump diodes and thermally conductive spacers mounted within a single indentation in a substrate or substrate clamps, so as to provide enhanced heat removal from the system. These systems also may include a plurality of such pump diode assemblies mounted, in a symmetric or partially symmetric arrangement, around a lasing medium in a diode pumped laser system, to improve heat removal and/or excitation of the medium.

1 . A pump diode assembly for a diode pumped laser, comprising:
 a substrate defining an indentation;   a plurality of diode bars disposed within the indentation; and   a plurality of thermally conductive spacers disposed within the indentation and separating the diode bars.   
     
     
         2 . The pump diode assembly of  claim 1 , wherein the indentation is a substantially rectangular notch, and wherein the diode bars and the spacers are substantially rectangular and sized to fit within the notch. 
     
     
         3 . The pump diode assembly of  claim 1 , wherein the spacers are constructed from a high thermal conductivity material chosen from the set consisting of gold, copper, copper tungsten alloy, sapphire, beryllium oxide, and diamond. 
     
     
         4 . The pump diode assembly of  claim 1 , wherein the spacers are coated with metallic solder to provide an electrically conductive path between the diode bars and the spacers. 
     
     
         5 . A four-fold symmetric pump head assembly for a diode pumped laser, comprising first, second, third, and fourth pump diode assemblies, wherein the first and second pump diode assemblies are oriented substantially orthogonally to each other, and wherein the third and fourth pump diode assemblies are oriented substantially parallel to the first and second pump diode assemblies, respectively. 
     
     
         6 . The four-fold symmetric pump head assembly of  claim 5 , wherein the first, second, third, and fourth pump diode assemblies each include a substrate defining a substantially planar indentation, a plurality of diode bars disposed within the indentation, and a plurality of thermally conductive spacers disposed within the indentation and separating the diode bars. 
     
     
         7 . The four-fold symmetric pump head assembly of  claim 5 , further comprising first, second, third, and fourth optical heat spreaders disposed adjacent to the first, second, third, and fourth pump diode assemblies, respectively. 
     
     
         8 . The four-fold symmetric pump head assembly of  claim 7 , further comprising a lasing medium slab having four sides, each side adjacent to one of the optical heat spreaders, wherein the optical heat spreaders each are configured to conduct heat away from the lasing medium slab and to allow substantial transmission of radiation from one of the diode bars to the lasing medium slab, and wherein the pump diode assemblies are disposed sequentially along a longitudinal axis of the slab and are substantially nonoverlapping. 
     
     
         9 . An n-fold symmetric pump head assembly for a diode pumped laser, comprising a plurality of pump diode assemblies, wherein at least one pump diode assembly is oriented substantially parallel to each side of an n-sided nonrectangular regular polygon. 
     
     
         10 . The n-fold symmetric pump head assembly of  claim 9 , wherein the pump diode assemblies each include a substrate defining a substantially planar indentation and including a thermally conductive diamond spacer defining a floor of the indentation, a plurality of diode bars disposed within the indentation, and a plurality of thermally conductive spacers disposed within the indentation and separating the diode bars.