As I showed in my video blog in my last post, infrared light is invisible to the naked eye. You can detect its presence with an infrared viewer or infrared camera, but not many people carry those around with them. My green laser pointer emits infrared light in addition to the green light. This can be dangerous because that infrared light adds to the power of the total beam, and it makes the beam more capable of causing eye injury. That means the user has to be extra careful to not shine the laser toward people.
Infrared light isn't all bad though. Many high powered lasers, like CO2 or Nd:YAG lasers, use infrared light (a lot of it) to cut through materials. For CO2 lasers and Nd:YAG lasers, the output wavelength is 1064 nm, which happens to be the same wavelength of infrared light that my green laser pointer emits. The Nd:YAG laser is used for 3D engraving. Check out the video below to see how that works!
What else can infrared light be used for? Here is a project for those do-it-yourself-ers out there!
*************** AS ALWAYS, SAFETY FIRST! ***************
You can order an infrared laser* or LED (or buy a green laser pointer like mine and block only the green) and shine it toward an IR photodiode.
So what? What does this accomplish?
Well the photodiode will sense when the laser is shining on it AND WHEN IT ISN'T! If an object or person passes through the laser, the photodiode will know! People won't be able to see the beam or spot on the photodiode, so the system can be used for security purposes. Ever see laser trip alarms in movies or video games? This is how they would work!
*You could get away with a cheap red laser. Check out this link that shows the steps for the DIY project.
Many garage doors have a system like this (probably using an infrared LED) to detect whether there is an object or person under the garage door as it closes. You have probably seen this and may have, like me, had to jump over the beam while ducking your head if you want to close the door and get out at the same time!
*************** AS ALWAYS, SAFETY FIRST! ***************
You can order an infrared laser* or LED (or buy a green laser pointer like mine and block only the green) and shine it toward an IR photodiode.
So what? What does this accomplish?
Well the photodiode will sense when the laser is shining on it AND WHEN IT ISN'T! If an object or person passes through the laser, the photodiode will know! People won't be able to see the beam or spot on the photodiode, so the system can be used for security purposes. Ever see laser trip alarms in movies or video games? This is how they would work!*You could get away with a cheap red laser. Check out this link that shows the steps for the DIY project.
Many garage doors have a system like this (probably using an infrared LED) to detect whether there is an object or person under the garage door as it closes. You have probably seen this and may have, like me, had to jump over the beam while ducking your head if you want to close the door and get out at the same time!
Cool simple project. I have totally done the run and jump, especially as a kid without a key to the house. I never really thought of how the garage sensors works but it makes sense that it is an IR beam. Great post!
ReplyDeleteThanks Carlos. It's funny to think that the technology was there the whole time, and I am just now figuring out exactly how it works.
ReplyDelete