The laser-producing tubes found in many modern cutting and engraving machines are available in two distinct varieties. One commonly seen type of laser tube uses direct current (DC) electricity to excite the gases found within it.

The other style of tube employs radio frequency (RF) energy to achieve the same basic effect. Although both generate the required photons by elevating the energy levels of gases, these two kinds of tubes differ in some significant respects.

Two Types of Tubes, Each With Characteristic Strengths

Many laser machines can accept either type of tube, with all the relevant internals in each part varying to suit its particular mode of operation. As such, laser cutter and engraver owners can generally choose either kind of tube when a replacement for an existing one becomes needed.

Deciding which type of tube will suit a particular machine and owner the best typically comes down to a few issues. Some of the most useful factors to take into consideration when choosing between DC and RF tube technology include:

• Cutting performance. DC-based laser tubes produce a beam of energy as steady as the electric current that flows through them. While even a DC tube will eventually need a rest, this general style of laser generation can be advantageous. RF tubes, by contrast, generate short bursts of laser energy with consistent gaps between them. When cutting relatively soft, heat-sensitive materials like acrylic, that can contribute to a bit of raggedness along the edges.

• Engraving ability. Many laser machines can just as well be used for engraving surfaces as for cutting clean through materials. RF laser tubes focus the photons they emit on smaller areas, which will allow them to produce finer engraving. This generally only becomes an issue, however, when the desired size of engraved details will be smaller than the cross-sectional profile of a DC laser.

Pricing and Lifespan Differ, as Well

These two basic types of tubes also differ significantly with regard to the price typical of each. A 60 watt laser tube that uses RF energy can be expected to cost several times more than one which employs DC electricity. As the former will also normally last quite a bit longer, the additional investment that is required, though, can easily pay off.