Friday, July 22, 2011

A Laser Pointer It's Not!

As per Request by anonymous ... July 18, 2011 at 8:40 pm.

For those of us who don’t already know, he term "laser" is an acronym for Light Amplification Stimulation Emission of Radiation (LASER); a medium, which is either gaseous or solid, and is excited to emit a single wavelength or consistent source of light. This laser light can be focused upon a point source resulting in high power densities, capable of vaporizing various materials. By controlling this power density, through the laser beam, and by utilizing the assistance of certain gases, laser cutting and welding can be achieved.

The not so common process of Laser cutting is the technology / expertise used to cut materials, such as various types of steel, wood, plastics, or paper. This process is typically used in industrial manufacturing applications, but of recent date, is also starting to be used by schools, small businesses and even hobbyists.  Another popular use that has become quite common in recent years: laser surgery.  Corrective eye surgery, such as the removal of eye cataracts, has become quite common.    The laser cutting process works by directing the yield of a high-power laser, by computer, at the material to be cut. The material then melts, burns, or is vaporized away, leaving a smooth high-quality finish on the edge of the cut.

 
Laser cutting and engraving applications are tremendously varied.

In the industrial market they are used for cutting and marking parts for:

·                     Medical and scientific components
·                     Point of sale displays
·                     Signage
·                     Architectural model making
·                     Electronic components
·                     Supplying the art and craft industry
·                     General engraving
·                     Rubber stamp industry
·                     Woodworking
·                     Musical instrument manufacture
·                     Textile and embroidery industry
·                     Pharmaceutical industry
·                     Defense industry
·                     Aerospace industry
The above list names only a few of the many possibilities.
Beyond industry, laser cutting and engraving are finding many applications within schools, colleges and universities particularly in departments for design and technology, and or the arts and engineering.

In other words, new uses seem to evolve with almost every machine that is sold.  It may be true to say that an example of laser engraving or laser cutting exists somewhere within every organization.

There are several advantages to utilizing the laser for cutting. (a) Due to the rapid rate of operation, the (heat) distortion to the base materials being cut is small. (b) The narrowness and accuracy of the cut are major advantages of this process. (c) Most complicated profiles can be cut. (d) Very hard material like silicon carbide, fragile materials like glass, or sticky material such as confectionery etc., can be cut by laser. (e) Laser cutting is also a quicker process compared to sawing and it is very efficient.
But there are Limitations.  The limit on thickness of selected material (for example a bit less than ¼ inch in plain carbon steel; for other metals it is even less). Current technology requires laser beam cutting to be coupled with “gas-jet” technology. … (Lasing Gases: N2 / CO2 / He) … then there is the potential radiation exposure danger.

In recent years, a few hobbyists have developed an interest in laser technology. Lasers devices used by these hobbyists are not only expensive (as much as $25,000) but they have radiation risks as well.  Compared to other hobby fields, laser hobbyists are much less common, obviously due to the high cost and probable radiation dangers implicated with the process.

Here is a cost projection for a “wealthy” hobbyist … An entry level laser with a 12" x 24" bed will run you about $11,000 to $15,000 depending on the brand and the options that are offered. They are self contained units that weight about 300 lbs and require and exhaust blower. Don't worry about the laser beams emitting radiation on this unit, these smaller lasers have coated glass that reflect the beam and will not operate with the top open, thus eliminating that risk.

Laser beams have been most famously exploited as weapon systems in numerous science fiction flicks, but actual laser weapons are still in the experimental stage. The general idea of laser-beam weaponry is to hit a target with a bunch of brief pulses of light. The rapid evaporation and expansion on the beam on the surface of object targeted, then causes shockwaves that damage the objective. The power required to project a high-powered laser beam of this kind is currently beyond the limit of technology as you might guess.

Currently, lasers of all but the lowest powers can potentially be used as incapacitating weapons, by utilizing their ability to produce temporary or permanent vision loss to varying degrees when aimed at the eyes. The nature and extent of vision impairment caused by eye exposure to laser light changes with regard to the power of the laser being used, the wavelength(s), the alignment of the beam, the exact orientation of the beam, and the duration of the experience. Lasers of even a small fraction of a watt in power are capable of causing immediate or permanent vision loss under certain conditions. Lasers used as weapons can be potential non-lethal but devastating weapons.

Here’s my attempt at summarizing or describing the laser cutting process.  Laser beam cutting (LBC) can currently be achieved by utilizing the radiation emitted by a focused beam of consistent light with the assistance of a high pressure gas. An assist gas, of a sort, is used to remove the melted and vaporized materials from the laser beam path. Both metallic and non-metallic materials can be cut by this laser beam process.


http://www.solarlasers.co.uk/applications.php                       

No comments:

Post a Comment