Company releases first-of-its-kind laser technology

14th March 2014

The first-ever 1 000 Hz transversely excited atmospheric pressure (TEA) pulsed carbon dioxide (CO2) laser, built for commercial applications, was launched in January by laser manufacturer PaR Systems’ Centre of Excellence (CoE) for SDI Lasers, based in Pretoria.

In contrast to the well-known continuous wave (CW) low-pressure carbon dioxide lasers, transversely excited (TE) CO2 lasers are operated at atmospheric and higher gas pressures and emit short bursts of energy durations of about 100 nanoseconds and peak powers of 10 MW at relatively high repetition rates.

TE CO2 lasers can be used in a number of highly specialised industrial and scientific processes, including the aerospace industry, atmospheric physics, isotope separation and accelerator technology.

Previously, TEA lasers, offered at atmospheric pressure, provided pulse energies of up to 5 J with pulse durations of 60 to 150 nanoseconds and at a maximum repetition rate of 600 Hz.

These lasers can be made to emit energy on a large number of individual fixed laser lines spanning the wavelength range from 9 µm to 11 µm in the mid-infrared.

Using the agile grating control system – also a proprietary component developed at PaR Systems – fully integrated into the laser control, single pulse wavelength selection is possible at repetition rates up to 100 Hz.

PaR’s scientists and engineers, in cooperation with the Laser Research Institute at the University of Stellenbosch, have developed enhancements such as the sidearm catalyst, the solid state switch and corona preionisation, now standard on the new 1 kHz TEA laser.

A sidearm catalyst system recombines the small amounts of carbon and oxygen created in the discharge and prolongs the gas lifetime.

In applications where extremely long gas lifetimes of more than one-billion laser shots are needed, this system saves on operating costs and reduces or eliminates frequent gas load changes.

A solid-state switched laser excitation circuit with a PaR-patented circuit topology replaces the conventional thyratron-based high voltage switching units.

The circuit has already demonstrated long-term reliable operation in excess of five-billion laser shots and PaR now estimates that this solid-state switch will prove to have a life in excess of ten-billion laser pulses.

A novel corona preionisation technique replaces conventionally employed spark preionisation and improves laser stability, extends gas life and provides long-term reliability.

The result of this partnership between industry and research institutions holds promise for many additional new developments presently being considered.