Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

Cheap ebay Pen Fun

ryanr256

New member
Joined
Nov 1, 2013
Messages
43
Points
0
I picked up a set of the cheap ebay red/green/blue pens:




I also had a glass block that had a motorcycle laser etched in it:



I decided to introduce the two. First the green:



Maybe a different angle?



Nothing very interesting I guess.

On to the red:



Again, nothing exciting.

Lastly, the blue:



Hey that's pretty cool! I pointed the beam at one of the edges. I tried the same thing with the red and green, but they didn't produce the same effect.

-Bob
 

Tmack

New member
Joined
Oct 13, 2013
Messages
2,478
Points
0
Hey cool effect. Wondering why the color change too. Sure someone will explain it soon.
 

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,586
Points
113
The green splits into three because the corner is chopped off so the beam hits three facets each directing the beam differently. It would remain a single beam if the entrance point wasn't at the corner. There's no color change here, though. There's a blue and a green in the last pic.
 

ryanr256

New member
Joined
Nov 1, 2013
Messages
43
Points
0
The green splits into three because the corner is chopped off so the beam hits three facets each directing the beam differently. It would remain a single beam if the entrance point wasn't at the corner. There's no color change here, though. There's a blue and a green in the last pic.
Um, no, that's all blue in the last pic. I'm not talented enough to hold a camera and activate two laser pens at the same time. :wink:

The last pic is a blue ebay pen aimed at the top front corner of the block from about a 45 degree angle. The glass (corner) is refracting the some of blue, creating the lines while allowing some blue to pass, illuminating the block.

-Bob
 

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,586
Points
113
Oh, ok then. Maybe there is some fluorescence threshold that is only exceeded in the incident beam while the reflected light isn't strong enough then?
 

Blord

New member
Joined
Dec 24, 2007
Messages
5,368
Points
0
That is a pretty cool effect with a blue laser that turns into green inside the glass.
I wonder if I can reproduce that effect with pieces of glass I have laying here around.

***edit*** If the glass is fluorescence like uranium glass then the color will turn into green.


 
Last edited:

LtKernelPanic

Well-known member
Joined
Sep 22, 2010
Messages
1,348
Points
48
Blord beat me to it. I've seen similar with my 405nm lasers. There's something in the glass that's phosphorescing under UV light* similar to the uranium marbles in the pic he posted. Depending how old that glass is it could be uranium glass which would explain it.




* Yes I know technically 405nm isn't UV light but it's close enough to the 400nm threshold where UV is defined to begin that it can trigger the phosphoresce effect.
 

djQUAN

Well-known member
Joined
May 27, 2013
Messages
1,133
Points
63
I believe the "blue" mentioned in the OP is a 405. I haven't seen a 3 pack with a 450nm diode in it. Or am I not up to date. :p
 

ryanr256

New member
Joined
Nov 1, 2013
Messages
43
Points
0
I don't know the wavelength (or power) of the "blue" laser. All I know is that it's a cheap ebay pen.

I've taken some more pics, this time with the lights on:









The interesting thing is that, unlike in Blord's pics, only the beam is changed to green. The glass itself is bluish, or maybe more violet? And, the beam exiting the glass is blue.

-Bob
 
Last edited:

Tmack

New member
Joined
Oct 13, 2013
Messages
2,478
Points
0
No doubt a 405. But that's so interesting how the wavelength is changed. I know it's been explained above but still neat.
 

brucemir

Well-known member
LPF Site Supporter
Joined
Aug 3, 2012
Messages
1,198
Points
113
When a 405nm is shined through glass it will turn green and if refracted around the glass enough. multiple colors. Here is a pic of two prisms next to each other and two 405's shot into them from opposite sides. You can see the effect

 

Blaster

New member
Joined
Jul 1, 2013
Messages
1,172
Points
0
I believe the "blue" mentioned in the OP is a 405. I haven't seen a 3 pack with a 450nm diode in it. Or am I not up to date. :p
Yes a 405nm ,if a eBay pen comes out in 445nm or 450nm that would be great .I would certainly get a few .
 
Last edited:

Dzarren

New member
Joined
Oct 16, 2013
Messages
66
Points
0
When a 405nm is shined through glass it will turn green and if refracted around the glass enough. multiple colors. Here is a pic of two prisms next to each other and two 405's shot into them from opposite sides. You can see the effect

Hey! I have both a pi/2 radians prism as well as a pi/6 radians prism, but i cant produce the effect you achieved using either or both prisms.


can you elaborate on how you did this? I keep playing with the angles but cant find a spot where colors other than green appear.


EDIT: i should have put it in degrees. 90 and 30 degrees respectively.
 
Last edited:




Top