I will start my mini physics lesson with the visible light spectrum. It makes up an incredibly small portion of the entire EM spectrum.
Everything from X-rays having an extremely high frequency to radio waves having extremely low frequency are made up of the same "material" called photons. However, as humans we are only able to detect a small interval of these frequencies with our eyes known as visible light. Keep in mind that "black" is the absence of light and "white" is the presence of all visible light frequencies "mixed" together. Everything we can see that has color is reflecting (NOT emitting) certain frequencies of light. For instance a flashlight(that is emitting all colors of light making it white) shining on an object that appears red is reflecting only red colored light and is absorbing all the other colors. What happens to all the other colors? The object absorbs them in the energy form of heat. This is why black objects that have been in the sun for a while become hot. Since black doesn't reflect any light, all of that light energy from the sun is absorbed and stored as heat, as opposed to white objects which reflect all frequencies of light and therefore no energy is absorbed.
Here is a chart that displays what colors of light make up other colors. Green, Red, and Blue are the Primary LIGHT colors. With them we can make any other visible color. Except black or course. So, if I were to emit a perfectly green light at a perfectly red or blue object, the object would absorb all the light as heat energy and heat up. If I were to shine that same green light at something green, then the object would reflect all of that light and remain a certain temperature. What does perfect mean? Well, a perfect red light would have a wavelength of 700nm (nanometers). Blue is 470nm, and green is 530nm.
Imagine if you had a device that could emit a perfect and consistent frequency of light(flashlights emit all frequencies of light so not too much help there). You could shine it on objects that you know would absorb all or most of its energy and transfer tons heat energy with light! Even to the point where the object couldn't handle that much energy and combusted! Well, these devices are actually very common and they are called lasers.
Lasers(Light Amplification by Stimulated Emission of Radiation) emit a single wavelength of light, and the light is concentrated into a very little diverging beam. As you probably already know, lasers have a million uses but some of those uses(that I'm interested in) require a very high powered laser. To give you an idea of what a high power laser is; some companies actually use lasers to cut material for products. They can even cut through thick steel! Just remember that all that energy is from a simple beam of light or in some cases Infared, but that has just a slightly lower frequency than light.
The lasers you can buy from pet stores or office supply stores are lasers that have a power of 5mw(milliwatts) or less. These are called class IIIa lasers. Their only use is to project a colored dot on a nearby surface. Like the one pictured above. These have applications such as pointing out something on screen or tricking your pet into thinking is a small animal to chase. You may have seen or heard of people popping balloons or lighting match heads with lasers but those lasers are MUCH more powerful. 11 times more powerful to be exact. Yes, with our atmosphere and its contents it will normally require a laser of at least 55mw to burn an object that is darkly colored. This is because the heat energy being generated will be transferred to the air around the object, and in order to "burn" the object must absorb energy faster than it can dissipate it back in to the atmosphere. For instance, if you wanted to pop a balloon you would need to color a black spot on it so the balloon can absorb more energy. However thats if you only had a 55-100mw laser. What if you had a laser that was 100 times or more powerful! I mean, a laser so powerful that it has laws against their usage and transportation and is in a whole separate class! A class IV laser means that the output power is 500mw or more(this is the highest class of lasers).
Like I said earlier, I would be taking this science to an EXTREME. So, I've ordered a class 4 laser which will be arriving two days from now! It is has a peak output of 600mw and will be able to burn just about everything thats not white. In which case I will color it with a sharpie. If you are familiar with the laser world, you would probably ask if it was actually 600mw and I would tell you that it is a Laserglow Technologies product. So yes it definitely will attain 600mw. Its called the Hercules-500
It requires a key to power it up and safety glasses are a must! I've also ordered the detachable lens along with the tripod mount, AC power adaptor and extra safety glasses. The laser it self weighs over 3 pounds and has its own cooling system with an auto shut-off if it starts over heating. And for us laser fanatics… 532nm, Beam divergence is .8-1.2 mrad. Or .08-.12 mrad with 10X beam expander. 2.5 watt Pump diode. And 100% duty cycle!
All of this together makes this the most powerful portable/handheld laser available(its in the Guinness book of world records)
I will be posting many follow up videos and pictures once I get it. If you have any ideas of stuff to burn, leave a comment!