You are here

Compact Laser Drivers for Photoconductive Semiconductor Switches



The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 5.4.c.(8) of the solicitation.

OBJECTIVE: The objective is to develop low-cost, compact, fast-rise-time, low-jitter pulse charging and laser trigger systems for photoconductive semiconductor switches (PCSSs) (ref. 1-15) to enable their application to many DoD applications including Electromagnetic Pulse (EMP) (ref. 6) and High Power Microwave (HPM) (ref. 7) systems. Cost of the technology will be a driver for the feasibility of scaling to large arrays and to multiple pulsed power system applications.

DESCRIPTION: Gallium arsenide (GaAs) PCSS technology has been demonstrated with switching and timing jitter times under 1 nanosecond (ns) for voltages up to 100 kV (ref. 1-2). The low timing jitter enables the development of planar or phased arrays of modular EMP or HPM sources. Each module is anticipated to fit within a 1 meter cube, most of which is filled by the radiating antenna structure. To enable the development of arrays of high voltage pulsers based on PCSS technology, it is preferable to have charging/triggering systems that are fully electrically isolated. Existing GaAs PCSS cannot sustain DC voltages without breaking down. This requires that the switched storage capacitors must be pulse charged in a few microseconds to ±50 kV or 100 kV total. For an EMP test capability and many pulsed power applications, a shot rate of a few per hour is adequate, but higher shot rates would be needed for many HPM applications. A compact, battery-powered pulse charging system is desired for an EMP test capability to avoid the requirement for power cables that will cause loading and reflections on the antenna array. The pulse charging system can be based on spark gaps, MOSFETs, inductive technologies, or any other approach that can achieve the needed size, efficiency, and reliability. Triggering a GaAs PCSS requires ~10-100 microJoules (µJ) of 840-880 nanometer (nm) laser energy per cm2 of switch area delivered in ~1 ns. Many laser technologies can achieve this, but rendering the system compact and low cost will require research and innovation. For an initial EMP demonstration it will take ~3 cm2 of switch area to conduct 1 kA with at an initial voltage of 100 kV. The timing jitter of the laser trigger system must be <0.3 ns 1σ. For maximum scalability and safety for an EMP array, it is desirable to have the laser trigger system integrated into each module. However, a single laser driving multiple fiber optic cables with adjustable relative timing may be adequate for an initial demonstration.

PHASE I: The minimum objective for Phase I will be the design of compact pulse charging and laser triggering systems adequate to drive an EMP array module based on GaAs PCSS technology. The pulse charging system should be capable of charging a 1 nFd capacitor to 100 kV in <10 µS. The laser trigger system should be capable of delivering 300 µJ of 840-880 nm light uniformly to a 1.5 cm by 2 cm switch area with <0.3 ns 1 σ timing jitter. Bread boarding and demonstration of any high risk components or the complete systems would be preferable.

PHASE II: For Phase II the objective will be to fabricate and demonstrate pulse charging and laser triggering systems adequate for 9-module EMP array based on GaAs PCSS. Each module should fit within a 1 meter cube and have an initial pulse charge of 100 kV across the PCSS. The test objective is to demonstrate that the timing jitter of the individual modules is <0.3 ns 1σ.

PHASE III DUAL USE APPLICATIONS: For Phase III the initial application is anticipated to be a transportable EMP test array that can be easily configured for either vertical or horizontal polarization. The contractor will have to work with DoD and civilian agencies to customize the test capability for various mission critical system and infrastructure applications. Other applications of the PCSS triggering systems are expected to include future large-scale pulsed power systems requiring many thousands of high reliability spark gap triggering systems (ref. 2-4). The contractor will have to work with the National Nuclear Security Administration to define the detailed requirements.


    • “Fiber-Optic Controlled PCSS Triggers for High Voltage Pulsed Power Switches”, Zutavern, F.J.; Reed, K.W.; Glover, S.F.; Mar, A.; Ruebush, M.H.; Horry, M.L.; Swalby, M.E.; Alexander, J.A.; Smith, T.L.; Pulsed Power Conference, 2005 IEEE, 13-17 June 2005 Page(s):810–813.


    • . “Optically Activated Switches for Low Jitter Pulsed Power Applications”, Zutavern, F.J.; Armijo, J.C.; Cameron, S.M.; Denison, G.J.; Lehr, J.M.; Luk, T.S.; Mar, A.; O'Malley, M.W.; Roose, L.D.; Rudd, J.V.; Pulsed Power Conference, 2003. Digest of Technical Papers. PPC-2003. 14th IEEE International, Volume 1, 15-18 June 2003 Page(s):591-594 Vol.1.


    • . “PCSS Lifetime Testing for Pulsed Power Applications”, Saiz, T.A.; Zutavern, F.J.; Glover, S.F.; Reed, K.W.; Cich, M.J.; Mar, A.; Swalby, M.E.; Horry, M.L.; Pulsed Power Plasma Science, 2007. PPPS 2007. Conference Record - Abstracts. IEEE, 17-22 June 2007 Page(s):189–189.


    • . “A Novel Application of GaAs Photoconductive Semiconductor Switch in Triggering Spark Gap”, Wei Shi; Linqing Zhang; Liqiang Tian; Lei Hou; Zheng Liu; Plasma Science, IEEE Transactions on, Volume 37, Issue 4, Part 2, April 2009 Page(s):615-619.


    • “Fiber-Optically Controlled Pulsed Power Switches”, Zutavern, F.J.; Glover, S.F.; Reed, K.W.; Cich, M.J.; Mar, A.; Swalby, M.E.; Saiz, T.A.; Horry, M.L.; Gruner, F.R.; White, F.E.; Plasma Science, IEEE Transactions on, Volume 36, Issue 5, Part 3, Oct. 2008 Page(s):2533–2540.


    • “Photoconductive, Semiconductor Switch Technology for Short Pulse Electromagnetics and Lasers”, Zutavern, F.J.; Loubriel, G.M.; Mar, A.; Hjalmarson, H.P.; Helgeson, W.D.; O'Malley, M.W.; Denison, G.J.; Pulsed Power Conference, 1999. Digest of Technical Papers. 12th IEEE International, Volume 1, 27-30 June 1999 Page(s):295-298 vol.1.


    • “Development and Testing of Bulk Photoconductive Switches Used for Ultra-Wideband, High-Power Microwave Generation”, Burger, J.W.; Schoenberg, J.S.H.; Tyo, J.S.; Abdalla, M.D.; Ahern, S.M.; Skipper, M.C.; Buchwald, W.R.; Pulsed Power Conference, 1997. Digest of Technical Papers. 1997 11th IEEE International, Volume 2, 29 June-2 July 1997 Page(s):965-969 vol.2.


    • “3C-Silicon Carbide Photoconductive Switches”, Senpeng Sheng; Xiao Tang; Spencer, M.G.; Peizhen Zhou; Wongchotigul, K.; Device Research Conference, 1996. Digest. 54th Annual, 24-26 June 1996 Page(s):190–191.


    • Charge Transport and Persistent Conduction in High Gain Photoconductive Semiconductor Switches Used in Pulsed Power Applications, Islam, N.E.; Schamiloglu, E.; Plasma Science, 2000. ICOPS 2000. IEEE Conference Record


    • “On-State Characteristics of a High-Power Photoconductive Switch Fabricated From Compensated 6-H Silicon Carbide”, Kelkar, K.S.; Islam, N.E.; Kirawanich, P.; Fessler, C.M.; Nunnally, W.C.; Plasma Science, IEEE Transactions on, Volume 36, Issue 1, Part 2, Feb. 2008 Page(s):287–292.


    • “Pulsed and DC Charged PCSS Based Trigger Generators”, Glover, S.F.; Zutavern, F.J.; Swalby, M.E.; Cich, M.J.; Loubriel, G.; Mar, A.; White, F.E.; Pulsed Power Conference, 2009. PPC '09. IEEE, June 28 2009-July 2 2009 Page(s):1444–1447.


    • “Development of a Lateral, Opposed-Contact Photoconductive Semiconductor Switch”, Richardson, M.A.; Stoudt, D.C.; Abdalla, M.D.; Skipper, M.C.; Schoenberg, J.S.H.; Pulsed Power Conference, 1999. Digest of Technical Papers. 12th IEEE International, Volume 1, 27-30 June 1999, Page(s):307-310 vol.1.


    • . “Optically-Activated GaAs Switches For Compact Accelerators and Short Pulse Sensors”, Zutavern, F.J.; Loubriel, G.M.; Helgeson, W.D.; O'Malley, M.W.; Ruebush, M.H.; Hjalmarson, H.P.; Baca, A.G.; Power Modulator Symposium, 1996., Twenty- Second International, 25-27 June 1996, Page(s):31–34.


    • “30 kV and 3 kA Semi-insulating GaAs Photoconductive Semiconductor Switch”, Shi, Wei; Tian, Liqiang; Liu, Zheng; Zhang, Linqing; Zhang, Zhenzhen; Zhou, Liangji; Liu, Hongwei; Xie, Weiping; Applied Physics Letters Volume 92, Issue 4, Jan 2008 Page(s):043511-043511-3.


    • “Multi-Filament Triggering of PCSS for High Current Utilizing VCSEL Triggers”, Mar, A.; Serkland, D.K.; Keeler, G.A.; Roose, L.D.; Geib, K.M.; Loubriel, G.M.; Zutavern, F.J.; Pulsed Power Plasma Science, 2007. PPPS 2007. Conference Record - Abstracts.


KEYWORDS: Photoconductive Semiconductor Switch (PCSS), Laser Driver, Gallium Arsenide, pulse charging, Electromagnetic Pulse, High Power Microwave

  • TPOC-1: Major Andrew Lerch
  • Phone: 703-767-2780
  • Email:
  • TPOC-2: Steven W. Seiler
  • Phone: 703-767-2877
  • Email:
  • TPOC-3: John F. Davis III
  • Phone: 703-767-6362
  • Email:
  • TPOC-4: Hoa Nguyen
  • Phone: 703-767-2947
  • Email:
US Flag An Official Website of the United States Government