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Multi Mode vs. Single Mode

RedCowboy

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I was making a point about how much I like real Tem00 laser beams and linked a couple youtube videos to make a point.

These demonstrate beam quality in a video format and I felt like sharing with everyone in case they don't see these elsewhere.

2.5 watts of multi mode 445 vs. 0.5 watts of single mode 405
The 445 even need a helper lens to do the job....slowly.


2.5 watts 445 multi mode.
0.5 watt of 405 single mode.
 

gozert

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Nice videos. The difference in single/multimodes definitely matters when burning. I can't say it's a fair comparison though, since the 405's balloons were black opposed to orange balloons for the 445.
 

RedCowboy

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Nice videos. The difference in single/multimodes definitely matters when burning. I can't say it's a fair comparison though, since the 405's balloons were black opposed to orange balloons for the 445.
Orange absorbs 445nm very well, why do you think 445 safety glasses are amber/orange.

My bet is it wouldn't do it with black balloons so they had to use orange.

I have done this across my backyard with my cinder block house as a backstop and a half watt 405 will smoke black paper but 3 watts of 445 will not, not without a special zoom lens that catches the diodes output at about 1 inch wide and focuses it like a cone from 1 inch to a 3mm spot with wings.


@ Shakenawake: Sweet :)
532nm kicks ass, no doubt about it.
I would rep you but it wont let me yet.
 
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gozert

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I don't think it would've popped the black balloons any slower than orange. Otherwise they would've used orange balloons for the 405 as well. Black absorbs light better than any other color.
 

RedCowboy

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@ gozert

Did you watch the 190 black balloons and the 1.5 watt 532nm laser, still beats the hell out of a multi mode 445.
I will see if I can find a black balloon video with a 445 multi mode, you will see how it can't compete because of it's horrible divergence.

Compare to this:

You can see how the first 24 balloons in the 1/2 watt 405 string had no pause, they just popped.
Not the same with this 2 watt 445, and if 76 more black balloons were lined up behind these 24 the spot size at the end would be too big to pop the last balloons.

Don't get me wrong, I enjoy the affordable power and multi mode projector diodes have possibilities, I even like wide beams, but I hate the floodlight divergence when focused to infinity, it just looks wrong and I must correct this, and I will.
 
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gozert

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Yeah I saw that video. Divergence really matters with experiments like these. Multimodes don't stand a chance against single modes or even DPSS up to a certain power.
 

APEX1

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add some pics from dtr or lazerer of the beam specs! awesome thread though!!!
 

RedCowboy

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add some pics from dtr or lazerer of the beam specs! awesome thread though!!!
Beam specs are fantastic, these are made to write in those tiny groves on a Blu-ray disc, that's through a single lens I do believe and a very impressive energy density, they focus to a extremely tiny spot to burn a spinning disc with quite high precision.

I need to get some BDR-209's from DTR, sooner or later dvd's are going to go the way of cassette tapes as digital memory and instant wireless downloads will replace it and the 405 won't be needed for burning disc anymore.
 

Gabe

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That video of the .5W 405 popping that line of balloons was nearly orgasmic. Imagine the 1W single mode.... :drool:
 

Lifetime17

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Hi Red,
Great vids lots of work here.nice presentation and editing .. Well done!
Rich:)
 

RedCowboy

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Hi Red,
Great vids lots of work here.nice presentation and editing .. Well done!
Rich:)
I do post some of my own videos and I have some across my backyard with my cinderblock lower of my house as a backstop showing different lasers with different lenses that I need to upload.

But these balloon videos are just youtube vids that I said right up top that I linked from youtube, fair use and all that, I felt like the balloons made a good demonstration and wanted to share my find for those who have not already seen them, but I will post more of my own in the future too.

The stuff I have loaded at youtube is not all that well edited, I just shoot and post. My humble videos are here: https://www.youtube.com/user/redcowboy1986
 
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Pi R Squared

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Beam specs are fantastic, these are made to write in those tiny groves on a Blu-ray disc, that's through a single lens I do believe and a very impressive energy density, they focus to a extremely tiny spot to burn a spinning disc with quite high precision.

I need to get some BDR-209's from DTR, sooner or later dvd's are going to go the way of cassette tapes as digital memory and instant wireless downloads will replace it and the 405 won't be needed for burning disc anymore.
Maybe not 405nm, but this may or may not be true. See this thread and read the article in the OP from more than 2 years ago: http://laserpointerforums.com/f44/high-capacity-dvd-storage-83369.html

Alan
 

Benm

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Single mode for the win :)

Btw, anyone noticed that guy using is hand as a beamstop in the very first video? Multimode or not, doesn't seem wise with 2.5 watts of power!
 

RedCowboy

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Single mode for the win :)

Btw, anyone noticed that guy using is hand as a beamstop in the very first video? Multimode or not, doesn't seem wise with 2.5 watts of power!
Freeze it at 0:07 you will see he is holding a black round disc to block the beam.
 
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Benm

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Oh, just watched in the replay - quick hands :)

Still love how that 405 chews through 100 of them faster than the 2 watt needs for only 24. Divergence on the multimodes really is pretty terrible. When used within a few meters range link across a living room it doesnt seem too bad, but at larger distances it becomes quite ridiculous. At 50 meters out it's really just a line, nothing resembing a dot/circle.
 




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