How To Make A Laser Pointer
This video is designed to show you what fun science can be by giving you a cheap and easy way to make a laser pointer at home with basic everyday items.
Today we're going to make a laser pointer out of household materials, things you can find in your house. There's one thing you have to buy but most things you can find in your house. I'm going to make a laser pointer and this would be useful for doing presentations and pointing at things.
So the sort of things that we are going to need are we are going to need an old torch or a cheap torch like this that we can pull apart, a DVD player that we can take apart, some batteries that we can test it with, some crocodile clips, and you need to buy something here this is called a laser body which is costs about 2 or 3 pounds on EBay, they're very cheap to buy, and those are all bits you need. Also you need some screwdrivers, quite a lot of different screwdrivers, including some very small ones like jewellers screwdrivers and some little pliers like these that hold everything. And you're also going to need a soldering iron and some solder and all those sort of things.
So to start with, you need to have a DVD player, because if we are going to make a laser we need a laser and you can find lasers in a couple of places in your house and one of them is a DVD player. Make sure you use an old DVD player that's lying around or broken, often they break and it's not the laser that breaks in them it's something else. So get an old DVD player, it doesn't work with a CD player.
Ok, so you do get lasers in CD players but the lasers in CD players are infrared lasers which means you can't see them so they're no good for making laser pointers. The lasers in DVD players are red lasers so they're good for making laser pointers with. So we are going to open up the DVD player, you need your screwdriver to unscrew it, unscrew the one side here and the back.
Take the lid off and this is what's inside the DVD player, you've got the bit that the DVD sits on and you've got lots of electronics. You're going to have to unscrew the DVD bit, normally some screws on the side like that that I've unscrewed to take that out. And if you turn the DVD player over you will see various motors that make the DVD player spin.
And you can see those are the motors and then there's a bit here which is the bit that reads the DVD and this has a laser in it. Somehow you have got to get the laser out. OK so you can use the various screwdrivers and you need to the bit here that reads the DVD, and it's usually on two rails that makes it move across the DVD.
So you will want to unscrew that, get the rails out and then it will come out nicely. Then you get that bit out and don't need all those other bits. This is the head that reads the DVD player, its got a laser in it and its got various mirrors and lenses and things like that in it as well.
So to get this one out first of all you need a small screwdriver because it has some small screws in it, and also you need your soldering iron because they're usually stuck in with a bit of glue and the soldering iron melts the glue nicely to get it out. So you would use the soldering iron, I've already done this one, but you would use the soldering iron and you'd melt the glue around it like that and pull the laser diode, that's what it's called a laser diode, you'd pull that out. So you don't really need the rest of the DVD player so you can get rid of that now.
The laser diode is the bit we need and it's this gold bit inside and it's usually protected by a metal casing and that's because when you put a voltage across it gets quite hot. Alright you've got your laser diode, the next thing we need to do is we need to put it in a body, a metal body to protect it so that it doesn't overheat when you put a battery, when a touch a battery to it. So this is a very cheap laser body, it's just a little thing like this, I bought it off the internet.
So if you take one of these laser bodies apart it gives you a gap that you can get the laser diode that you've picked out of your DVD player right inside and that gives it