Since I could be on to something here the following maybe-formal text describes what I believe really is a new invention:
Inside a laser waveguide where laser light is 'folded' in a zig-zag pattern using mirrors, the intensity of the beam is increased by effectively lengthening the optical resonator with the mirrors. This is commonly done with multiple mirrors where the beam bounces once per mirror, which results in a requirement to align a multitude of mirrors to a high degree of accuracy. Even in large industrial lasers this alignment is done manually, often by a man with a wrench, which is costly and time-consuming.
Invention and some theory:
None of the patents for waveguide lasers I have reviewed mention that; putting one pair of parallel mirrors at nλ ± ½λ and at a small angle to them another pair of parallel mirrors at nλ means that only the nλ pair causes light amplification, as the other pair interferes destructively. This lets the beam that is stabilized by the nλ pair of mirrors be folded a large number of times between the pair of mirrors at nλ ± ½λ.
Prior art, and such:
I assume that the reason the industry has not adopted this approach lies in the perceived difficulty of maintaining a pair of mirrors at a set half-wavelength from each other while the entire device flexes, expands and contracts from thermal expansion. It is however possible to have this degree of accuracy and control for laser light; which is especially true at the longer, mid-infrared wavelength of the CO2 laser where it can be done cheaply.
Piezoelectric devices respond with small movement to high voltage, which translates to a ultra-fine precision when the voltage is well-behaved. Usually piezoelectric actuators built for the purpose cost hundreds of dollars, but according to my interpretation of https://www.comsol.com/offers/conference2012papers/papers/file/id/13148/file/13943_garcia_paper.pdf the degree of control needed for laser mirror alignment of a CO2 laser can be had for a mere pittance.
Conclusion / claims:
My plan, (should some soulless greyface attempt to claim this invention as their own...) is to actuate the mirrors of a CO2 laser with piezo disks and to drive the actuators with e.g. a 8051 microcontroller. To alleviate friction the mirrors can be mounted on an air cushion. The distance between the mirrors is constantly monitored,e.g. by a laser beam power meter, and the output of the sensor is fed back through the automation system to adjust the voltage of the actuators and keep the laser's power at the desired power level.