Triggering of Pressurized Gas Switches With a Class I Laser

Abstract

The use of lasers to initiate the closure of high-power gas switches was initially explored soon after the development of suitable high-power pulsed lasers in the 1960s. The low jitter, excellent triggering range, and galvanic isolation provided by laser triggering have been extensively exploited in the triggering of megavolt switches in large pulsed power machines. The fact that the lasers and optical systems used in these machines are very large, complex, and expensive and have led to the perception that these are unavoidable characteristics of laser triggered gas switches, leading to a reluctance among the directed energy and compact pulsed power community to consider their use in compact pulsed power systems. The Advanced Pulsed Energy, Ionization, and Discharge Center (APERIODIC) Research Group at The University of New Mexico (UNM), Albuquerque, NM, USA, has been investigating novel triggering technologies for compact pulsed power. One of the technologies under investigation is a system we have named the microintegrated laser switch (MILS) [1]. This system holds the potential to overcome the limitations of traditional laser triggering of gas switches in compact applications. As part of the preliminary work on developing the MILS concept, UNM has collaborated with MegaWatt Lasers, Hilton Head Island, SC, USA, to conduct laser triggering experiments using a commercial off-the-shelf (COTS) erbium-doped glass passively Q-switched microlaser. This 28 mm × 9 mm laser produces 4-ns pulses at 1535 nm with an average energy per pulse of 244 μJ. One of the principal advantages of this laser is that, due to the wavelength and energy, it is a class 1 laser and can be operated without the stringent controls necessary for the lasers typically used for laser triggering.