Image By User:Eino81 – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=8003112
The original LASER invention (as I recall) was a glass like mineral ruby rod with a photo (xeon) flash tube wound around the outside. One end of ruby rod was reflective. The firing end was semi-reflective. I don’t think these were used as industrial LASERs. More like a scientific curiosity.
Today there are three major engraving/burning small format industrial LASER types. One of the oldest is the CO2 LASER using a glass tube containing CO2 gas. The LASER tube is large and fragile and needs water cooling for sustained firing of the LASER. The beam travels long through the air path of several 90-degree direction changes reflected by mirrors, the last mirror is on the moveable print head. Benefit is high power (>40 watt) energy levels but with short <2000-hour tube life.
The next popular type is called the fiber LASER. It uses a LASER diode and amplifies the light through bundled flexible glass fibers to concentrate and amplify the laser pulse. Generally used for engraving metal. A fiber LASER can have long LASER life due in part to short period intermittent use.
The last type is the blue LASER diode. Low power diodes of this color are used in “blue ray” DVD systems. It uses optical lens to focus and concentrate the LASER beam.
Higher power LASER diodes are now popular for use in hobby level engravers and cutting systems. Power out level are between 1 watt to about 8 watts output. Generally advertised by input power (watts) to make them appear to be 4 to 5 times more powerful (7-to-40-watt input) compared to a CO2 LASER rated by output power. (A form of false/trick advertising but not necessarily unlawful)
Some of the lower power blue Diode LASERs are rated for 20.000 hours of use. However, many application variables and user abuse can shorten the diode life considerably.
For hobbyist use the range of Diode LASER power (1w -8w) is adequate for most hobby desktop engraving/cutting applications. The cost of ownership is on par with the current low end 3D printers from China. ($150 – $600)
Any greater power the cost will increase significantly. I found one low-end CO2 40 Watt LASER priced at $500. Ten watts higher at 50 watt was $1000 additional ($1500). Commercial engraving systems are commonly in the $4k-$5k and higher range.
High power metal cutting, and LASER weapons are a totally different class of LASER.
Hobbyist Use
I have given LASER cutters and engraver ownership occasional consideration for well over a decade. CO2 lasers were always just far too expensive as a hobbyist toy. It was easy to realize the marketing hype to sell them to hobbyists was just a lot of smoke and mirrors. It still is today.
Owning a single LASER engraver doesn’t suddenly put one into a high paying business or profitable hobby as the marketing presentation often portrays. When I have considered the customer potential of LASER burned items, I always discover it is simply a tool that can produce added decorative value to the products to which it is applied.
If I were making and selling boxes, I could decorate the boxes with burned in designs. I would not be selling just the designs, but rather the more attractive boxes that incorporate the design. The epiphany in this is that it is not the engraving but what is being engraved that has the whole value. A LASER engraver with nothing to engrave is nothing at all.
Pyrogravure
When I was a kid, I had a craft/hobby called “Wood Burning” A tool was sold by Ungar which is a hot soldering iron with a sharp tip used to burn decorations into a “paint-by-number” design printed on a wood sheet. It’s called Pyrography today. LASER engraving is automated pyrography. It gets a mention in Wikipedia as a form of pyrography.
What has changed is the cost of low power LASER hardware is now extremely low. I no longer require a personal justification for a return on the investment of thousands of dollars. I don’t need to have a clear and present use application.
My expectation is to discover creative ways to LASER burn decorations. It’s a type of “playing with fire” The LASER is a tool, just like a pencil. What it produces is no better than the abilities of person who can fully understand how it works and to what extent that person applies that knowledge.
As I have discovered with 3D printing. It is not the tool that is creative but the person who knows how to use it.
My goal with an investment in a low cost LASER is to learn and experience what can be produced with CNC pyrography and utilizing the creative advantage of computer applications required.