laser wavelength change?

[Wolfman29]

This is fascinating. I want to see some pics!

 

[jeffreythe00]

Interesting, I going to sub to this thread. Please post results if you manage to get some!

 

[Blade]

well, im not gonna be able to test this out tonight, i have too much homework and i have to prepare a speech im giving on lasers tomorrow for my public speaking class . but you have my word that i'll test this as soon as i get the chance.

 

[honeyx]

For me a green beam appears also a bit more blueish at the night sky. Exactly like for you. Thought in my case I´m sure it´s just an illusion. When watching at it at home it appears quite normal. Maybe it´s to our eyes seeing everything more blueish in the darkness.

 

[Blade]

For me a green beam appears also a bit more blueish at the night sky. Exactly like for you. Thought in my case I´m sure it´s just an illusion. When watching at it at home it appears quite normal. Maybe it´s to our eyes seeing everything more blueish in the darkness.

yes i agree, but what makes this situation so significant to me is that i saw the beam change while i was shining it toward the sky, and i never seen it that way before. and BTW my eyes are very sensitive to blue light...

the reason i mentioned the sodium light is because that was where i was pointing when i noticed the difference. but now now im starting to see there are too many factors in this situation to really hit the nail on the head with accurate results, but i think its worth a try for the sake of experimentation IMO x3

 

[honeyx]

Did this sodium lamp turn on when you noticed the difference? I´s quite possible your eyes were saturated by the soduim bulb light and became even more sensitive to blue. It´s like pointing first with a blue laser and then watching to a green. The green appears then a bit more yellowish.

 

[Meatball]

If the Nd:YAG, or Nd:YV04 or whatever lasing medium your laser is made from, just so happens to have horribly off dielectric coatings on the ends, there is a chance the your "undesired" lines will lase.

Now, if you're getting blue, that's also assuming that the undesired line is very strong... strong enough to be doubled in a KTP optic... which is generally not done unless the power density achieved is above some threshold.

I can see this happening better if it were found that your laser was using an LBO optic instead, which can and is done from time to time on the 532nm units, but generally I would expect KTP to be in there. LBO is used for wavelengths that (when doubled) go deeper into the blue spectrum, where KTP doesn't tend to cooperate as much.

 

[Eudaimonium]

If the Nd:YAG, or Nd:YV04 or whatever lasing medium your laser is made from, just so happens to have horribly off dielectric coatings on the ends, there is a chance the your "undesired" lines will lase.

Now, if you're getting blue, that's also assuming that the undesired line is very strong... strong enough to be doubled in a KTP optic... which is generally not done unless the power density achieved is above some threshold.

I can see this happening better if it were found that your laser was using an LBO optic instead, which can and is done from time to time on the 532nm units, but generally I would expect KTP to be in there. LBO is used for wavelengths that (when doubled) go deeper into the blue spectrum, where KTP doesn't tend to cooperate as much.

As far as I know, LBO is never actually used in 532nm systems, since it's incredibly innefficient there, same with KTP being inefficient at blue colors.
Correct?

But, being inefficient does not mean it cannot pull it off, you know, one in a million chance it actually does produce some blue along side of green, making the beam the color described.

I so want to see this laser measured on a spectrometer.

 

[Blade]

uh, i dont think o-like uses LBO :crackup: but ive heard some bad things about o-like and if they happen to grow their own crystals and coat them, i would more agree to the laser having bad dielectric coatings...

i can only try to get this laser measured. my parents arent fans of technology as i am and therefore dont understand the purpose of shipping it to someone else. i know that sounds just plain stupid but they give me a hard time with everything they dont understand. and theyre definitely not gonna let a $250 instrument go farther than the front door.

how much will a spectrometer cost?

 

[Cyparagon]

A proper spectrometer is out of your price range. Get a diffraction grating, first.

Mr. Eudaimonium, Are you sure about the 473? I'm pretty sure that 946nm is a YAG line and all modern green pointers use YVO4.

 

[Blade]

i wouldnt doubt that lol. and yeah im gonna order a diffraction grating.

and im pretty sure my laser contains YVO4

 

[Eudaimonium]

Mr. Eudaimonium, Are you sure about the 473? I'm pretty sure that 946nm is a YAG line and all modern green pointers use YVO4.

As a matter of fact, I'm pretty sure I saw you saying exact same thing (cheapo greens emitting faint 473nm) somewhere. That's why I said it.

Now ofcourse, I am NOT 100% sure of it, nor that it is true, but it sounded right as an explanation for the color shift.

Besides, you can't even be sure what crystal exactly is in the laser. Everything remains a possibility, right?

 

[weeba2kv]

Hmm my laser in this pic ( with my monitor serrings ofcourse does show here a lil blueish color

not sure what others will see but on the left it's mint green

pic taken with an XPERIA phone not edited with PhotoS

 

[Blade]

yeah i see, and thats the color...

well i tried to get some results last night and.... nothing.... the beam stayed 532 all the way.

im gonna try a few more times while changing my variables slightly each time (battery power, location etc.) to be accurate. and its not like the dudy cycle is helping me any ...

 

[Meatball]

As far as I know, LBO is never actually used in 532nm systems, since it's incredibly innefficient there, same with KTP being inefficient at blue colors.
Correct?

You'll find LBO being used in Coherent's "Verde" linup.

Its the series with arguably some of the best 532nm beam specs achievable.

 

[weeba2kv]

Well when i was on this topic here i became curious about all this , later on i found this pic and yeah amazingly i do notice this mint green in my picture weird but really this is just a clean picture without photoshop bullshit