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Question about wavelengths and purpose

LEDbeam

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I've noticed that all the talk about blue lasers are all about their burning power. When the talk is concerning green lasers, then it's about using them to point to things. But if the power level of a green laser was increased enough, they burn things as well.

Also, I noticed blue lasers are always 1W or more in power, and the price is reasonable. But if the power is increased that much on a green version, the price skyrockets.

Are blue lasers simply cheaper to produce? Do they make poor pointers? The reason I'm asking is because (as a newbie) I wanted to get one that is high powered in order to be very bright and projects far away. Blue versions seem to always be high powered while being reasonably priced (such as Sci Fi Lasers SB501B), while green ones cost more even though lower powered.

I've also done some reading and heard that blue lasers don't produce a nice dot, but rather a line, a smudge, or other weird shape. Is that inherent to blue lasers? I'm sure those traits would make it a not-so-great distance laser. But I'd love to hear the input of those here with experience.
 



Razako

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I've noticed that all the talk about blue lasers are all about their burning power. When the talk is concerning green lasers, then it's about using them to point to things. But if the power level of a green laser was increased enough, they burn things as well.

Also, I noticed blue lasers are always 1W or more in power, and the price is reasonable. But if the power is increased that much on a green version, the price skyrockets.

Are blue lasers simply cheaper to produce? Do they make poor pointers? The reason I'm asking is because (as a newbie) I wanted to get one that is high powered in order to be very bright and projects far away. Blue versions seem to always be high powered while being reasonably priced (such as Sci Fi Lasers SB501B), while green ones cost more even though lower powered.

I've also done some reading and heard that blue lasers don't produce a nice dot, but rather a line, a smudge, or other weird shape. Is that inherent to blue lasers? I'm sure those traits would make it a not-so-great distance laser. But I'd love to hear the input of those here with experience.
Blue lasers(445nm) are cheap to get a high power variant because they're direct diode lasers. IE they just consist of a driver circuit, a laser diode and a focusing lens.

Green 532nm costs more for higher powers because they're more complex to make. They involve an IR laser diode and a sequence of crystals which convert the IR light into 532nm green. The plus side is that 532 nm green lasers usually have much better beam specs than 445nm. They're generally more visible because of wavelength sensitivity and they project a better beam to long distances.

If your goal is strictly to buy a laser with great visibility and long distance pointing power I'd say to get a 532 nm in the 50-200mw range. If you want burning power then the direct diode blue lasers really can't be beat. They also have 520 nm green diode lasers now, but I don't know a whole lot about them and haven't had a chance to buy one yet.
 
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NightExplorer96

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Blue lasers(445nm) are cheap to get a high power variant because they're direct diode lasers. IE they just consist of a driver circuit, a laser diode and a focusing lens.

Green 532nm costs more for higher powers because they're more complex to make. They involve an IR laser diode and a sequence of crystals which convert the IR light into 532nm green. The plus side is that 532 nm green lasers usually have much better beam specs than 445nm. They're generally more visible because of wavelength sensitivity and they project a better beam to long distances.

If your goal is strictly to buy a laser with great visibility and long distance pointing power I'd say to get a 532 nm in the 50-200mw range. If you want burning power then the direct diode blue lasers really can't be beat. They also have 520 nm green diode lasers now, but I don't know a whole lot about them and haven't had a chance to buy one yet.

520nm green diodes are available up to 1W(so same power level as some 445nm diodes) for around hm.....$200-$400 I believe? They also tend to have quite a short duty cycle if not heat sinked very, very well! :yh:

-Alex
 

paul1598419

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I believe DTR is asking less than that for the 520nm laser diodes. You can get the lower power 9mm for around $165 or so and it can be pushed to 1 watt. The higher power 9mm is about $235 and can be pushed over 1.4 watts.
 
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ElectricPlasma

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Love the profile pic LEDbeam, great to see another trekkie on here! :D

To answer your inquiries, blue is generally easy to find in higher class, usually class IV (See laser classifications, http://www.lasersafetyfacts.com/resources/Arrow---eye-injury-hazard.png) while 532nm green is most common lower than class IV. This is because, as others have stated, 532nm green is converted infrared light through crystals. A lot of power and light is lost this way and as a result its difficult to find under class IV.

I'm gunna guess that one of the reasons blue lasers are cheaper at higher powers is because they're pretty mass produced, just think about blue-ray players, they use a blue laser diodes for their discs.

With the most recent 520nm green direct diodes coming into the market, those bring a different story to the table. 520nm green works similar to how blue works (~445nm) as the light is coming directly from the diode, rather than converted from IR light. This allows for higher wattage for green at lower prices, because there are no expensive or complex crystals or any of that nature, and no IR light with low efficiency,it is specifically diode driven light from the core.

Now don't get me wrong, class IV 532nm green is definitely a possibility and is also real. Only thing is, most of the time it'll be a lab laser and not a handheld.

Feel free to PM me if you're confused about anything, I might be able to help.

-Sean
 

NightExplorer96

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I'm gunna guess that one of the reasons blue lasers are cheaper at higher powers is because they're pretty mass produced, just think about blue-ray players, they use a blue laser diodes for their discs.

Blue-ray actually is ~405nm diodes. So blu-ray uses violet diodes :D :D :D :D

-Alex
 

ElectricPlasma

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Blue-ray actually is ~405nm diodes. So blu-ray uses violet diodes :D :D :D :D

-Alex

Hm, never knew that :eek: I had actually thought they were 445nm because of the project videos I have seen from them eg "Make a powerful blue laser from a blue-ray player". Anyway, good to know! :D :thanks:
 
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Hm, never knew that :eek: I had actually thought they were 445nm because of the project videos I have seen from them eg "Make a powerful blue laser from a blue-ray player". Anyway, good to know! :D :thanks:

445nm diodes mostly come from projectors. There's a certain brand that is the Ye who shall not be named. Sounds like Classy-hoe.
 

LEDbeam

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Love the profile pic LEDbeam, great to see another trekkie on here! :D

Thank you!

I'm gunna guess that one of the reasons blue lasers are cheaper at higher powers is because they're pretty mass produced, just think about blue-ray players, they use a blue laser diodes for their discs.

This makes sense! I've been reading about lasers for many years, and I remember way back when the mw values went up on a laser, the price went up with it. Eventually, someone made and sold a 1 watt handheld, and it cost at least $1,000. I think that was just when blu-ray became a thing. So imagine my surprise when I can now buy a 2.4 watt blue laser for $130 from Sci Fi Lasers, yet a comparable green one now would still cost what a blue one cost back then. Sometimes things can seem too good to be true, but other times, great things can actually happen! :beer:
 

LEDbeam

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Blue lasers(445nm) are cheap to get a high power variant because they're direct diode lasers. IE they just consist of a driver circuit, a laser diode and a focusing lens.

Green 532nm costs more for higher powers because they're more complex to make. They involve an IR laser diode and a sequence of crystals which convert the IR light into 532nm green. The plus side is that 532 nm green lasers usually have much better beam specs than 445nm. They're generally more visible because of wavelength sensitivity and they project a better beam to long distances.

If your goal is strictly to buy a laser with great visibility and long distance pointing power I'd say to get a 532 nm in the 50-200mw range. If you want burning power then the direct diode blue lasers really can't be beat. They also have 520 nm green diode lasers now, but I don't know a whole lot about them and haven't had a chance to buy one yet.

I think I'll end up with the blue one because I don't really want to spend too much on it right now. Sci Fi Lasers has a deal where I can get a blue one at 1.5--1.8W (not sure if that means it's adjustable power, or simply could vary on specs) for $100 without batteries or charger. That's the best deal I've seen anywhere so far based on my limited knowledge.
 

Razako

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I think I'll end up with the blue one because I don't really want to spend too much on it right now. Sci Fi Lasers has a deal where I can get a blue one at 1.5--1.8W (not sure if that means it's adjustable power, or simply could vary on specs) for $100 without batteries or charger. That's the best deal I've seen anywhere so far based on my limited knowledge.
Sounds good. You should be pretty happy with it. Just be careful with it, because at that power level a reflection off a street sign or something could cause eye damage. Also avoid looking at the dot on things closer than a hundred feet or so.
 

ElectricPlasma

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I think I'll end up with the blue one because I don't really want to spend too much on it right now. Sci Fi Lasers has a deal where I can get a blue one at 1.5--1.8W (not sure if that means it's adjustable power, or simply could vary on specs) for $100 without batteries or charger. That's the best deal I've seen anywhere so far based on my limited knowledge.

No laser is ever 100% stable for various reasons; temperature, efficiency etc. 1.5 - 1.8W is the range of stability of power, which means it's output will probably always be between 1.5W and 1.8W. I would direct you to read a lot about safety, these things can take out your sight in a fraction of a second. Now unless you're just pointing it to the sky (Like I love to do {just make sure you watch for aircraft}) You're definitely going to need safety glasses. I think just about everyone on this forum can recommend the Eagle Pair from Survival Lasers, it's about 40 USD iirc which is cheap as far as laser safety goggles go. I think you'll love that laser; I remember how amazed I was when I got my first 445nm laser. Also remember, you'll probably be upgrading as you get more fascinated with it. I never intended to go past my first laser as I thought it was pretty expensive; turns out it's the cheapest laser I own :yh:
 

LEDbeam

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No laser is ever 100% stable for various reasons; temperature, efficiency etc. 1.5 - 1.8W is the range of stability of power, which means it's output will probably always be between 1.5W and 1.8W. I would direct you to read a lot about safety, these things can take out your sight in a fraction of a second. Now unless you're just pointing it to the sky (Like I love to do {just make sure you watch for aircraft}) You're definitely going to need safety glasses. I think just about everyone on this forum can recommend the Eagle Pair from Survival Lasers, it's about 40 USD iirc which is cheap as far as laser safety goggles go. I think you'll love that laser; I remember how amazed I was when I got my first 445nm laser. Also remember, you'll probably be upgrading as you get more fascinated with it. I never intended to go past my first laser as I thought it was pretty expensive; turns out it's the cheapest laser I own :yh:

I was reading on another thread that you can buy regular yellow safety glasses at places such as a hardware store for about $3 and they provide adequate safety for blue lasers. I can't seem to find that thread now, but I remember the guy had around 6,000 posts under his name and sounded very experienced. But even with these, I would be leery of using the laser much indoors. I wouldn't want to take a chance unless maybe I was shining it directly at something dark in color. Otherwise, I'd use it outdoors, shining it either at the sky or a distant object at least 50 feet away.
 

diachi

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I was reading on another thread that you can buy regular yellow safety glasses at places such as a hardware store for about $3 and they provide adequate safety for blue lasers. I can't seem to find that thread now, but I remember the guy had around 6,000 posts under his name and sounded very experienced. But even with these, I would be leery of using the laser much indoors. I wouldn't want to take a chance unless maybe I was shining it directly at something dark in color. Otherwise, I'd use it outdoors, shining it either at the sky or a distant object at least 50 feet away.


Yeah, some folk have used those, and they have tested to be "fine". That said, is it worth risking your eyesight for the sake of saving $40? ;)
 

trussmonkey25

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Yeah, some folk have used those, and they have tested to be "fine". That said, is it worth risking your eyesight for the sake of saving $40? ;)
Could somebody do a test with a pair and lpm, tell what shades they are talking about?
 




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