R, G & B Laser General

[trevorboultwood]

Hello!

I've just stumbled across this forum due to inspiration to create my next project; Laser projector. As a bit of a background im an electronics engineer now software developer and so therefore my physics/optics knowledge is very limited!

I've looked through a handful of pages and found it most useful however I am a bit concerned with the safety of the projector I have in mind! Ideally this project will be used in the house and at parties so i dont want ANYONE to injure themselves.

I need each R G & B/C to be safe for drawing on the wall and the potential of being shon on people for effects and whilst looking through the internet for a blue laser I came across the exact sort of form factor I am after such as the one below. Right size, TTL, heatsink and a decent price. However 100mW!!! I probably only need 20mw for each laser right?

What sort of lasers would you guys suggest for a project like this? Its also the same for red and probably green. Should i just get three laser pointers?


Enjoying the thought of this all coming together!

Trevor


bangood . com /405nm-100180300mW-Blue-Violet-Dot-Laser-Module-Variable-Focus-TTLPWM-Modulation-w-Heat-Sink-2_54-3P-for-DIY-Laser-Engraver-p-1594449.html?rmmds=search&ID=6280286&cur_warehouse=CN

 

[gazer101]

Hello!

I've just stumbled across this forum due to inspiration to create my next project; Laser projector. As a bit of a background im an electronics engineer now software developer and so therefore my physics/optics knowledge is very limited!

I've looked through a handful of pages and found it most useful however I am a bit concerned with the safety of the projector I have in mind! Ideally this project will be used in the house and at parties so i dont want ANYONE to injure themselves.

I need each R G & B/C to be safe for drawing on the wall and the potential of being shon on people for effects and whilst looking through the internet for a blue laser I came across the exact sort of form factor I am after such as the one below. Right size, TTL, heatsink and a decent price. However 100mW!!! I probably only need 20mw for each laser right?

What sort of lasers would you guys suggest for a project like this? Its also the same for red and probably green. Should i just get three laser pointers?


Enjoying the thought of this all coming together!

Trevor


bangood . com /405nm-100180300mW-Blue-Violet-Dot-Laser-Module-Variable-Focus-TTLPWM-Modulation-w-Heat-Sink-2_54-3P-for-DIY-Laser-Engraver-p-1594449.html?rmmds=search&ID=6280286&cur_warehouse=CN

If you want your projector to be eye-safe you should 3 mW laser diodesl blue, green, and red and create an monitor of some sort that reduces their power inputs so that at any given time only 5mw of laser light is emitted by the 3 combined lasers. The other option is to buy more powerful diodes but greatly disperse the beam

 

[Giannis_TDM]

Hello!

I've just stumbled across this forum due to inspiration to create my next project; Laser projector. As a bit of a background im an electronics engineer now software developer and so therefore my physics/optics knowledge is very limited!

I've looked through a handful of pages and found it most useful however I am a bit concerned with the safety of the projector I have in mind! Ideally this project will be used in the house and at parties so i dont want ANYONE to injure themselves.

I need each R G & B/C to be safe for drawing on the wall and the potential of being shon on people for effects and whilst looking through the internet for a blue laser I came across the exact sort of form factor I am after such as the one below. Right size, TTL, heatsink and a decent price. However 100mW!!! I probably only need 20mw for each laser right?

What sort of lasers would you guys suggest for a project like this? Its also the same for red and probably green. Should i just get three laser pointers?


Enjoying the thought of this all coming together!

Trevor


bangood . com /405nm-100180300mW-Blue-Violet-Dot-Laser-Module-Variable-Focus-TTLPWM-Modulation-w-Heat-Sink-2_54-3P-for-DIY-Laser-Engraver-p-1594449.html?rmmds=search&ID=6280286&cur_warehouse=CN

1rst of all sorry to disappoint you but making a laser projector is hard and totally not beginner friendly I can still give you some info on the most basic laser projector you can create (ps if the beam is not stationary and is moving you can get away with using more powerful LD without harming anybody) This are the parts needed for a basic projector:
1 single mode red diode Sharp GHG0631IA2G ( you want all the diodes to be single mode for optimal beam specs)
1 single mode blue diode Osram PLT5 450B
1 single mode green diode Osram PL520B
A pair of calibrated X and Y galvos (sorry I dont have links for that)
Amplifiers for those galvos
3 LD drivers
2 dicros ( one reflect blue and pass green and red Reflect blue pass green and red and reflect red pass green Reflect red pass green)
And a controller (sorry no links here)
as you can see a laser projector needs a lot of different parts and connecting them, Aligning the optics setting up the controller is a whole other ordeal I suggest you build some lasers first to get familiar with them and then trying.

 

[trevorboultwood]

If you want your projector to be eye-safe you should 3 mW laser diodesl blue, green, and red and create an monitor of some sort that reduces their power inputs so that at any given time only 5mw of laser light is emitted by the 3 combined lasers. The other option is to buy more powerful diodes but greatly disperse the beam

That’s an interesting thought and wow, ok I will probably buy some LDs with a custom driver to get them working. I suppose one benefit is the cost; the LD will be super cheap at this power.

I would of thought I needed more power if the beam was moved all over the place.

 

[trevorboultwood]

1rst of all sorry to disappoint you but making a laser projector is hard and totally not beginner friendly I can still give you some info on the most basic laser projector you can create (ps if the beam is not stationary and is moving you can get away with using more powerful LD without harming anybody) This are the parts needed for a basic projector:
1 single mode red diod you want all the diodes to be single mode for optimal beam specs)
1 single mode blue diode
1 single mode green diode
A pair of calibrated X and Y galvos (sorry I dont have links for that)
Amplifiers for those galvos
3 LD drivers
2 dicros ( one reflect blue and pass green and red and reflect red pass green
And a controller (sorry no links here)
as you can see a laser projector needs a lot of different parts and connecting them, Aligning the optics setting up the controller is a whole other ordeal I suggest you build some lasers first to get familiar with them and then trying.

Excellent info, yes I will be buying the diodes and a small driver board. Thank you for the information it’s really well received.

I’ve had a few technical projects prior to this and I feel that I’m up to scratch. I found arduino sketch someone made which incorporates a single laser and I will be implementing the other two colours.

It’s a large project and I hope I can link a computer to contour images to be displayed real time from a movie, but that’s to come!

I found the galvos arnt as expensive as I first thought and you can get some cheap and cheerful set from AliExpress for sub 50£!

Thank you! I look forward to posting some of my results!
(I had to remove your links as new here)

 

[Giannis_TDM]

Excellent info, yes I will be buying the diodes and a small driver board. Thank you for the information it’s really well received.

I’ve had a few technical projects prior to this and I feel that I’m up to scratch. I found arduino sketch someone made which incorporates a single laser and I will be implementing the other two colours.

It’s a large project and I hope I can link a computer to contour images to be displayed real time from a movie, but that’s to come!

I found the galvos arnt as expensive as I first thought and you can get some cheap and cheerful set from AliExpress for sub 50£!

Thank you! I look forward to posting some of my results!
(I had to remove your links as new here)

Hey nice I like to see that you are not giving up even with how difficult this project is, I too work with combining lasers and arduinos and just today finished a project that has a laser mounted on 2 servos to point it at any direction, the thing that will interest you is that i found an extremely efficient way to dim the LD with any driver via code on the arduino if you want ill explain it to you and give you the code that achieves that.

 

[paul1598419]

One thing that's sticks out here is that each of your lasers will need too be set at powers that are not the same. You want a basic white beam out and green is far more visible mW for mW than red or blue. And the red is going to likely be set lower than the blue as 635nm is more visible than 450nm. So, each laser will have to be set to give you the best white balance, then you can modulate them.

 

[trevorboultwood]

Hey nice I like to see that you are not giving up even with how difficult this project is, I too work with combining lasers and arduinos and just today finished a project that has a laser mounted on 2 servos to point it at any direction, the thing that will interest you is that i found an extremely efficient way to dim the LD with any driver via code on the arduino if you want ill explain it to you and give you the code that achieves that.

I'm always up for looking at code! I suppose this also replies to @paul1598419 I could use PWM to control the laser power in order to get a better balance. But my first call is to buy lasers.

Im thinking mainly about cost here but here is my idea so far:

ebay.co.uk/itm/Focusable-12V-500mW-808nm-Infrared-Laser-Diode-Dot-Module-TTL-Fan-Cooling-Kit/193179877367?hash=item2cfa6afff7:g:l6sAAOSwQ69dtquT

Taking this and replacing the laser inside as this is a kit that contains all the necessary parts... but im hesitant to place an order of three as im not sure if this is feasible...

 

[paul1598419]

That link is for a 808nm IR laser rated at 500 mW. You can buy RGB lasers from Techhood on eBay for ~$50 with a driver board that you can set the individual powers of each laser. Then, you can TTL modulate them. I have one and they run off a +12 volt supply.

 

[trevorboultwood]

That link is for a 808nm IR laser rated at 500 mW. You can buy RGB lasers from Techhood on eBay for ~$50 with a driver board that you can set the individual powers of each laser. Then, you can TTL modulate them. I have one and they run off a +12 volt supply.

Ahahaha!! So development, ive not even looked at your link but I have already ordered one along with a salvo unit.

The only difficult part at the moment is the software to drive the darn thing....

 

[gazer101]

You could use an arduino to modulate the laser power no?

 

[trevorboultwood]

You could use an arduino to modulate the laser power no?

So I’m looking at using both an arduino and audio dac solution with a switch between.

There’s a few animations online to be done through audio and an arduino can be used alongside for safety as well as controlling simple patterns as well as colouring.

I have reserved tomorrow to design a pcb!

 

[gazer101]

So I’m looking at using both an arduino and audio dac solution with a switch between.

There’s a few animations online to be done through audio and an arduino can be used alongside for safety as well as controlling simple patterns as well as colouring.

I have reserved tomorrow to design a pcb!

Sure, please post what you decide to do. I'm curious to see how it turns out!

 

[Cyparagon]

Do NOT point lasers at people. IF and ONLY if you've done the necessary maximum permissible exposure (MPE) calculations, written the proper attenuation maps, installed a shutter actuator, scan fail-safes, and several other interlocks can it be moderately safe to "audience scan". Audience scanning is NOT a first project.

That being said, as long as you're not pointing the laser at people, and not at reflective surfaces, the power isn't that much of an issue.