Class IIIa to Class 1 Red Mod

[purduephotog]

First posting here- do you have any idea how hard it is to search for class 1 laser information when users are given that name when they join???

That said-

I participate in a program called FIRST Robotics- one of the rule changes this year is the permissibility of using Class 1 lasers for targeting. We'd like to modify class 3a laser pointers (the cheap ones you get in keychains, etc) to run at class 1 power levels.

I have access to the necessary equipment to determine the output power (full metrology lab at work)

I realize most folks want More Power... but I need less.... much much less. Can anyone provide an example or perhaps an idea as to what driver modification we could use (I'm familiar with CC drivers from work with high powered LEDs).

Thanks Kindly-

 

[Cyparagon]

The output power is proportional to the input current. Ideally you can simply lower the current until you get the output power you want. The problem is the threshold current (the point where the laser starts to work) is not zero. I just tested a 5mW module, takes 3V at 20mW, outputs 3mW. It doesn't emit light (over a few µW anyway) below 15mA which turned out to be 0.8mW. Your results may vary. Using a filter (something as simple as gray transparent plastic perhaps) might be a better option for you.

 

[purduephotog]

The output power is proportional to the input current. Ideally you can simply lower the current until you get the output power you want. The problem is the threshold current (the point where the laser starts to work) is not zero. I just tested a 5mW module, takes 3V at 20mW, outputs 3mW. It doesn't emit light (over a few µW anyway) below 15mA which turned out to be 0.8mW. Your results may vary. Using a filter (something as simple as gray transparent plastic perhaps) might be a better option for you.

Thanks for the test data! I hadn't considered the possibility of a minimum lasing current, although I should have realized that was a distinct possibility.

I will also take a look at the possibility of using ND filter material over the laser to lower the effective output power. That would be an even better solution if I can get it approved.

Thank you.