Towards a triggerable switchless TEA CO2 laser

On the operation of switch-less transversely excited atmosphere CO2 lasers in the oscillator and amplifier configurations

“…We have demonstrated the possibility of optically triggering a switch-less laser by transporting UV photons originating from another high voltage discharge (be it a spark gap or another mutually coupled parallel spark preionizer) through an optical fibre into the vicinity of one of the gaps of its parallel spark pre-ionizer. This preconditions the gap causing its closure followed by the closure of the remaining gaps of the parallel pre-ionizer resulting in the operation of the self-switched laser in synchronism with the external high voltage discharge [5]. In this paper we experimentally demonstrate the satisfactory operation of two self-switched lasers in the oscillator-amplifier configuration wherein the delay between the two can be varied as desired to obtain the best results.…”

Repetitive operation of switchless transverse flow transversely excited atmosphere CO2 lasers

“…[15][16][17][18][19][20][21][22] In this method, the preionising spark array, an integral part of the laser head, was made to serve the dual role; that of a switch as well as of a source of UV photons essential for the preconditioning of the inter-electrode volume. The sequential preionising spark array used in the initial stage of this study was constructed by segmenting the main spark gap into smaller adjustable gaps and then placing them in series along the length and to one side of the discharge.…”

“…[17][18][19] that, in turn, allowed perfecting this switchless operation technique by way of extending the operation to include wider discharge width 19 and conventional sized systems 20 that could also be operated in triggered mode. 21,22 Repetitive operation, which was the prime motivation for moving towards switchless configuration, has so far eluded us primarily due to the following reason. As the operating voltage of a switchless laser is governed by the preioniser gap length, 17 in order to have an independent control on the operating voltage of the laser and the composition of the laser gas mixture, the preionisation chamber is isolated from the main discharge by means of LiF windows 16,19,20 that offer high transmission to the UV photons in the 110-130 nm range known to cause effective photo preconditioning.…”