Introduction: Laser Pointer

Picture of Laser Pointer

Lasers these days come in many different shapes and sizes. Building your own, you also have the option of making it almost any color laser you want. There are new laser diodes that output violet, green, two shades of blue, three shades of red, and even infrared (IR), but you cannot see near IR very well, so you probably would not want that. (It's good for some other things, though.) Unfortunately, there are no yellow and orange laser diodes as yet; but you can purchase a DPSS module that will output those if you want, though they are a little pricey.

Step 1: The Stuff

Picture of The Stuff

Parts

  • Laser host (the outside, body, casing)

This one is up to you. The cheapest, easiest way is to buy a 650nm or 660nm (red cat toy color we have all seen) Chinese pointer from eBay and just swap out with a better, more exotic color (wavelength) of your choice. You can get as creative as you want. Use a toy gun, a real gun, or even 3D print the entire laser. Use your imagination!

Please vote at the top of the page. I really need a 3D printer!

This build uses the 685nm 35mW HLD685035K5J. If you want to use this one, just search for that part number on eBay. It is a beautiful deep red with an ever so slight purplish hue. If red isn't your thing, just search for 'laser diode'.

5.6mm 12x30mm AixiZ style module
There are also 3.8mm and 9mm laser diodes, as well as some other packages you won't want to use if this is your first build.

Avoid LED drivers! They can send current spikes that kill laser diodes!
Buy one that has the right current range and input voltage for your diode, and input voltage to match your cell(s).

  • Switch (If the driver does not have one)
  • Lens (If not included w/module)
  • Lithium ion or LiMn cell or cells (Depending on the voltage you need)

I highly recommend buying from lrsales on eBay to get the best cells.

  • Battery spacer (If your host is longer than your cells)

Try searching for 'battery spacer' on eBay.

This build used one from an old TV remote or something.

Tools

  • Safety Glasses

    These aren't absolutely necessary If you are careful, unless you decide to go with a diode >35mW. Any more than this and you will need them. Don't buy eBay or Amazon glasses, as most of them do not work. Never ever intentionally look directly into any laser, even with safety glasses, even if it seems like it's not working correctly.

    Even 2mW directly into an eye is enough to cause damage if left there long enough. Please, Please be safe! You only get one set of eyes.

  • 5 Minute epoxy
  • ESD strap (MUST be worn at all times when handling laser diodes and associated wiring)
  • Soldering iron
  • Solder
  • Soldering Flux
  • Diode press set
  • Vise or arbor press
  • Screwdrivers/allen keys/torx drivers (Some hosts may need these)
  • Needle nose pliers (Bending, forming leads)
  • Tweezers (For handling the diode without touching the window and lenses)
  • Hammer (For when things really go wrong)

Step 2: Surface Prep

Picture of Surface Prep

Most laser diodes have what is called a case pin - a pin that is connected to the outer metal casing and everything in good electrical contact with it. Since the HLD685035K5J does not have a case pin, some method must be devised to attach a wire to the host body (positive in this case).

The type of module pictured is chrome plated. If you tried to solder to it as-is, you would discover just how well solder will stick to chrome, or rather how it does not. So 120 and 220 grit sandpaper is used to expose a little bare brass. It then gets washed thoroughly inside and out with soap and water and then rinsed with isopropanol to remove all traces of grit and oils residue.

Step 3: Soldering the Case Connection

Picture of Soldering the Case Connection

Flux is then applied and the wire is soldered on. Be careful not to get any solder in the threads if you plan to thread the back on again. This takes a lot of patience and iron "seat time" to do it right.

Step 4: Soldering the Other Connections

Picture of Soldering the Other Connections

Press the diode into the module with a genuine Flaminpyro diode press set and a vise or arbor press. Bend the leads in an attractive fashion and solder them to the driver board. Be sure to observe all polarities and always wear a grounded ESD wrist strap when handling laser diodes and associated wiring. Use a little flux on every joint and only enough heat to melt the solder and no more.

If your iron is not temperature controlled, regulate the temperature by unplugging it when the liquid solder begins to get so hot that it becomes dull from oxidation. Again, only use as much heat as is absolutely necessary. These are thermally sensitive components.

Step 5: Support Frame

Picture of Support Frame

When you press the button, there needs to be a firm support underneath it. Otherwise, the board will flex and eventually connections will become loose and break.

This wood bee the prefect place to use a 3D printer. The board slides in and locks in place with a small integrated plastic hook. If you are with me on this and do not have access 3D printing, a 1/2" wooden dowel rod makes an acceptable substitute. One must merely cut it in such a way as to provide support underneath the switch so that it doesn't move when it is pressed.

Seal the wood with polyurethane and epoxy the switch and support in place once it dries.

Step 6: Enjoy Your New Laser!

Picture of Enjoy Your New Laser!

Congratulations. You've now accomplished something very few people in the world have done - built a working laser! My assistant here is very proud of you.

But it isn't over yet
There are so many thigs you can do with lasers! See lots of other great Instcrutables and you will begin to get an idea. There's a good chance you will find something yourself and write your own Instructable about it!

Comments

Chinasaur (author)2015-04-16

Be careful with an infrared laser; you can't see it or feel it, but it can still blind you.

Zolf (author)2015-05-05

there is a step seven with nothing in it!

Fixed!

cool!

tinyweasel (author)2015-04-16

Can I ask you a bit of advice? I bought a 50mW green laser from eBay, and it is supposed to run off 3V, but I can't get it to. I ran it off 9V for a second but I didn't want to kill it. Any advice?

It probably needs a slightly higher voltage, like 3.7 - 4.2V from a lithium cell. Most of the Chinese lasers actually prefer them. The build above actually uses a 10440 cell (AAA size) and a spacer.

Thanks! I'll try a lithium one.

Kiteman (author)2015-04-12

Do I understand you correctly; you have dismantled a laser-pointer and rebuilt it into a laser-pointer?

Yes, basically, I changed the color of the laser.

Actually, it came to me completely gutted and missing its switch. Only an empty tube and a tail cap

A host can be made from anything. :D

This exchange made me laugh. The project reminds me of up-cycling plastic bags into crocheted plarn or fused-plastic bags: from one point of view, it's absurd, but if you tilt your head slightly, it's just cool. My head is sufficiently tilted: this is cool.

+1 to The Lightning Stalker for the project and +1 to Kiteman for pithily expressing the other point of view.

Thanks for your vote in the contest!
I need the 3D printer to make parts for a FirePick Delta.
Then there will be plenty of drivers for all of these lasers, and other things too,
like a temperature regulated medicine cabinet.

magnus.distefano (author)2015-04-15

What kind of diode is best fit for the laser? Is a diode >35mW recommended?

It depends greatly who will be using it and what is legal in your area.
I am in the United States, for instance, and handheld lasers above 5mW are legal to build and own, but not to sell inside the US. Here we cannot use ANY laser outdoors within 10mi of an airport under current law. (Not even a cat toy!)

There are also other considerations like security, for instance will there be children around? A child under 18 should not use a laser above 5mW. Of course this is up to the discretion of the parent, but a responsible child can be pressured to give it to another child who will put it in someone's eye. Even 1mW is enough to cause eye damage with some wavelengths.

It also depends on the size of your host and materials of construction. Aluminum and copper offer the best cooling. A pen like this can only cool well up to about 100mW. It depends on the diode, though some are more efficient than others. An 808nm diode might be able to do 500mW, but the output is infrared and barely visible. Any more would require a cool-down period we call a duty cycle.

jmarkw (author)2015-04-15

When making the laser how can you bump up the power to heat the target to the point of combustion.

Select a more powerful diode/driver combination.
You must also consider the power source and cooling for both the diode and driver.

baecker03 (author)2015-04-13

led drivers actually would work, just have to avoid the cheap Chinese ones with out proper filtering. another precaution I would take would be adding a low dropout regulator such as a 1117 adj

LED drivers are just too iffy. I don't recommend them unless they have been used in builds before or you know how to test with an oscilloscope.

pfred2 (author)baecker032015-04-13

Can you add filtering to LED drivers? I have a laser pointer project coming up I plan on doing. I am making my own current regulator for it though.

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