Triaxial photoconductive switch module
Methods, systems, and devices describe triaxial photoconductive switch modules that include a center conductor, an inner conductor, an outer conductor, a high voltage capacitor that is formed between the center conductor and the inner conductor, and a photoconductive switch that is formed between the center conductor and a section of the outer conductor. The disclosed triaxial photoconductive switch modules include low inductance current paths that lead to high current efficiencies. Furthermore, the disclosed triaxial photoconductive switch modules eliminate or reduce parasitic capacitance problems of existing systems.
1. A triaxial photoconductive switch module, comprising:
an outer conductor;
an inner conductor;
a center conductor;
a dielectric material positioned between the center conductor and at least a section of the inner conductor to form a high voltage capacitor; and
a photoconductive switch formed between the center conductor and a section of the outer conductor, wherein upon activation of the photoconductive switch, an electrical connection is formed between the center conductor and the outer conductor that enables a current to flow through the inner conductor, across the high voltage capacitor, through the center conductor, through the photoconductive switch and to the outer conductor.
2. The triaxial photoconductive switch module of claim 1 , further comprising a light source coupled to the photoconductive switch to enable activation of the photoconductive switch.
3. The triaxial photoconductive switch module of claim 2 , wherein the outer electrode includes an opening to allow light from the light source to be coupled to photoconductive material of the photoconductive switch.
4. The triaxial photoconductive switch module of claim 3 , wherein the opening enables free space propagation of the light through the opening and onto the photoconductive material.
5. The triaxial photoconductive switch module of claim 3 , wherein the light source includes an optical fiber that couples light from the light source to the photoconductive material through the opening.
6. The triaxial photoconductive switch module of claim 5 , wherein the optical fiber includes an asymmetric concave end that is positioned inside the opening to allow the light from the optical fiber to enter the photoconductive switch at a non-normal angle of incidence.
7. The triaxial photoconductive switch module of claim 1 , wherein each of the outer conductor, the inner conductor and the high voltage capacitor forms an axially symmetric structure about an axis that runs through a center of the central electrode.
8. The triaxial photoconductive switch module of claim 7 , wherein:
the cylindrically symmetric structure of the high voltage capacitor is characterized by a base radius and a height, wherein the height of the symmetric structure of the high voltage capacitor is smaller than a height of the cylindrically symmetric structure formed by the inner conductor.
9. The triaxial photoconductive switch module of claim 1 , wherein the section of the outer conductor forming a portion of the photoconductive switch is configured as a cold plate to allow dissipation of heat generated by resistive loss in the photoconductive switch.
10. The triaxial photoconductive switch module of claim 1 , wherein the photoconductive switch further includes one or more surfaces having a high reflectance coating to allow confinement of light within a photoconductive material of the photoconductive switch.
11. The triaxial photoconductive switch module of claim 1 , wherein the section of the outer conductor forming a portion of the photoconductive switch includes a reflective surface to allow confinement of light within a photoconductive material of the photoconductive switch.
12. The triaxial photoconductive switch module of claim 1 , wherein the high voltage capacitor is formed as a cast-in-place capacitor.