Laser newb, a question about violet lasers

[zeetee]

I have looked around a little, so to preface: yes, I will be buying safety glasses and I will take the utmost care not to harm myself or others.

I'm interested in getting a green laser(because they seem cool), but violet lasers also look kind of neat so I'm considering getting one of those instead.

I would want a bright one, but I DON'T want one that will burn things/pop balloons/light matches/etc.

My question is: What is the highest mW I could go with a violet laser without it having any of the previously mentioned burning qualities? And, at that mW would it still be highly visible in a dark room/at night without smoke or fog?

 

[Rivem]

Violet (405nm) lasers are going to have to be pretty powerful to have a visible beam, but it's not bright at all due to our eyes' low sensitivity to their light. I've got around 100mW of 405nm, and the beam is just barely visible. It's already at a power level where it can just start to burn things, and it's more than enough to pop balloons and light matches.

If you want lower power with a visible beam, nothing will beat a green.

 

[Pi R Squared]

I have looked around a little, so to preface: yes, I will be buying safety glasses and I will take the utmost care not to harm myself or others.

I'm interested in getting a green laser(because they seem cool), but violet lasers also look kind of neat so I'm considering getting one of those instead.

I would want a bright one, but I DON'T want one that will burn things/pop balloons/light matches/etc.

My question is: What is the highest mW I could go with a violet laser without it having any of the previously mentioned burning qualities? And, at that mW would it still be highly visible in a dark room/at night without smoke or fog?

You are talking about 405nm, this is at the limit of the visible spectrum and is barely visible, you're not going to be satisfied with a spot of fuzz on the wall that you have to look for to even see it. You are going to want something over 500mW to have a good visible beam, and at that point it is dangerous and will easily burn stuff. Sorry that's just the way it is with 405nm because it's so dim to our eyesight compared to other colors, green is the brightest.

Alan

 

[zeetee]

Thanks for the info!

Yeah, I was worried it might be too dim. Just to verify though, are you guys talking about use during daytime/lighted rooms? Would a violet laser at pre-burning wattage have a visible beam in a darkened room/at night?

Again, thanks for the speedy replies!

 

[Sta]

Thanks for the info!

Yeah, I was worried it might be too dim. Just to verify though, are you guys talking about use during daytime/lighted rooms? Would a violet laser at pre-burning wattage have a visible beam in a darkened room/at night?

Again, thanks for the speedy replies!

Even at night my 100mW 405's beam is barely visible (scotopic). You would be better off getting a green if you'd like a visible beam without burning power.

 

[Rivem]

Even at night my 100mW 405's beam is barely visible (scotopic). You would be better off getting a green if you'd like a visible beam without burning power.

What Sta says. It has to be pretty dark, and your eyes have to get used to the dark a bit before you can see the dim beam. Even red beams are a bit more visible.

 

[zeetee]

Gotcha! Green it is!