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Encap

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Yes, there is too many people who are just too lazy to spent few minutes to background research on their own.. :beer:
Exactly.

Coonie:
The specs you are looking for don't exist. There is no "official comparison to beam specs compiled for these at say 25 feet" As GSS has told you.

The resulting beam/dot of a hand held laser is the combination of the size and shape of the diode output + whatever optics you choose to use and how whatever optics are used to shape, correct, and focus the diodes output in a particular build. There are many factors.

The beam/dot of all multimode diodes are relatively poor compared to an ideal DPSS laser. They are all bad some worse than others.

Members have given you the best advice they can give and their opinion as to which diodes area easier to achieve a better beam/dot with. There is no one formula or answer.

The rest is up to you to comprehend, research, and or experiment with as is how any hand held laser you assemble turns out.

If that is not good enough --just buy a complete laser from whatever manufacturer or vendor/reseller you want.
 

RA_pierce

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Yes, there is too many people who are just too lazy to spent few minutes to background research on their own.. :beer:
Let's be honest - information is scattered all over the forum as verbal descriptions, which does not make that advice very helpful.
There is very little organization for the information we gather and the attempts that have been made are often difficult to read (e.g. images of spreadsheets with tiny text), do not have good photographic documentation, and other issues.

While I totally understand the desire to berate newcomers and advise them to "use the f**king search," there is a limit to the usefulness of that advice because of the nebulous organization of information here.

I'd welcome anyone to prove me wrong - show me how a 30 minute scan of the forum can pull up information on beam characteristics for at least 25% these diodes with measurements, photos, and clear standardized comparisons.

Gaining this knowledge, if it exists here, requires A) sifting through a ton of often irrelevant conversation to find the nuggets of information in every relevant thread or B) a long history on the forum to accumulate bits of information from conversation and experience. This is not easy for newcomers.

"Read the stickies" and "use the search" are not always helpful comments especially with specific questions like this one.

My advice to Coonie:
If available, look at the data sheets for the diodes you are interested in.
Where the tables provide information of divergence angles, there will be two fields, one number for the parallel-axis (we can call it the x-axis for simplicity) divergence angle and one for the perpendicular "y-axis".
If you divide one by the other, you will get a ratio of the divergence angles for the x- and y-axes. The further that ratio is from 1, the more elliptical or bar-shaped the beam will be.
When the beam is highly elliptical (i.e the ratio is far from 1), it will be much more difficult to obtain a collimated beam with the convex lenses we typically use.
This is because the two axes diverge at different angles and so require different focal lengths to collimate them simultaneously.
So, for multimode diodes, your best bet is to go with one that has a divergence angle ratio as close to 1 as possible.
When such data is not available, you will have to try to fill in the gaps by searching for that particular diode and seeing if anyone has reported anything on the beam characteristics.
 
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Let's be honest - information is scattered all over the forum as verbal descriptions, which does not make that advice very helpful.
There is very little organization for the information we gather and the attempts that have been made are often difficult to read (e.g. images of spreadsheets with tiny text), do not have good photographic documentation, and other issues.

While I totally understand the desire to berate newcomers and advise them to "use the f**king search," there is a limit to the usefulness of that advice because of the nebulous organization of information here.

I'd welcome anyone to prove me wrong - show me how a 30 minute scan of the forum can pull up information on beam characteristics for at least 25% these diodes with measurements, photos, and clear standardized comparisons.

Gaining this knowledge, if it exists here, requires A) sifting through a ton of often irrelevant conversation to find the nuggets of information in every relevant thread or B) a long history on the forum to accumulate bits of information from conversation and experience. This is not easy for newcomers.

"Read the stickies" and "use the search" are not always helpful comments especially with specific questions like this one.

My advice to Coonie:
If available, look at the data sheets for the diodes you are interested in.
Where the tables provide information of divergence angles, there will be two fields, one number for the parallel-axis (we can call it the x-axis for simplicity) divergence angle and one for the perpendicular "y-axis".
If you divide one by the other, you will get a ratio of the divergence angles for the x- and y-axes. The further that ratio is from 1, the more elliptical or bar-shaped the beam will be.
When the beam is highly elliptical (i.e the ratio is far from 1), it will be much more difficult to obtain a collimated beam with the convex lenses we typically use.
This is because the two axes diverge at different angles and so require different focal lengths to collimate them simultaneously.
So, for multimode diodes, your best bet is to go with one that has a divergence angle ratio as close to 1 as possible.
When such data is not available, you will have to try to fill in the gaps by searching for that particular diode and seeing if anyone has reported anything on the beam characteristics.
Finally someone that understands. I can't read this entire forum and the stickies...well lets just say a lot of those don't even cover laser related topics.
I must not have stated my question clearly though. I gave a link to a website that sells diodes. There is no mention of dpss lasers. I think most of the people who replied seemed to have difficulty in understanding what I thought was a very simple question but it's ok.
I will conduct my own tests and with the data given to me from a few of you that is useful.

Thank you for your time.
 

RedCowboy

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Wow, you had some questions and got some good answers, I bet you were excited to complete a build, is there a thread of your laser that you built and your findings ?

I can't find your build thread so I will ask you some questions.

( 1 ) How did your comparison between the pltb450b and ndb7875 go?

( 2 ) Did you decide on a laser diode ?

( 3 ) Did you complete a build ?

( 4 ) Do you have any pics to share ?

( 5 ) I like the ndb7875 with a 3 element and with a G2 and 3X beam expander, which do you now like the best if you have both, or did you just build the one and how do you like it ?

( 6 ) Also what was your purpose for this laser and what have you done, please share your findings with the forum so we can see how answering your questions helped, I'm sure everyone will enjoy seeing the fruits of their efforts. :)
 
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GSS

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^^^^^^^^^^Thank you Red^^^^^^^^^
Some good info given and would of been nice to see what "Coonie" came up with.
New or novice members giving info is just as nice at times to what even experienced give:)
Wondering if he was discouraged or a hit and run guy?
 

RedCowboy

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Yes, I noticed coonie posting in a thread just yesterday so I thought I would ask.
 
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Wow, you had some questions and got some good answers, I bet you were excited to complete a build, is there a thread of your laser that you built and your findings ?

I can't find your build thread so I will ask you some questions.

( 1 ) How did your comparison between the pltb450b and ndb7875 go?

( 2 ) Did you decide on a laser diode ?

( 3 ) Did you complete a build ?

( 4 ) Do you have any pics to share ?

( 5 ) I like the ndb7875 with a 3 element and with a G2 and 3X beam expander, which do you now like the best if you have both, or did you just build the one and how do you like it ?

( 6 ) Also what was your purpose for this laser and what have you done, please share your findings with the forum so we can see how answering your questions helped, I'm sure everyone will enjoy seeing the fruits of their efforts. :)
This is quite an old thread. I think it would have been more appropriate to have pm'd me with your questions rather than revive the thread.

1. It didn't

2. No

3. No, obviously

4. Again, No

5. Uh, that's great. Thanks for sharing.

6. What does it matter?

I see your negative reputation score that you gave me. I have no idea why you did that.
 

RedCowboy

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That's another great question, and your answer is
 

GSS

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This is quite an old thread. I think it would have been more appropriate to have pm'd me with your questions rather than revive the thread.

1. It didn't

2. No

3. No, obviously

4. Again, No

5. Uh, that's great. Thanks for sharing.

6. What does it matter?

I see your negative reputation score that you gave me. I have no idea why you did that.
What the heck is wrong with you and the attitude? Why in the world would this be needed to be PMed?
I'm as nice and tolerate as they come but you really pissed me off dude and the in the OP's you did ask a hell of alot of questions that member's were happy to reply.
 
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CurtisOliver

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You revived the thread. 5 days is hardly necroposting.
And yes, what's with the attitude? We're just wondering how you got on.
 
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The attitude is only manufactured in your mind GSS. Getting pissed off over nothing is not healthy.
Curtis you need to look at those dates. It clearly shows that I didn't revive the thread. I don't mind but a lot of people get real angry when others do. I was merely just acting on that.

Please don't spam my pm's redcowboy. Thankyou. Bad enough you "accidentally" gave me a bad rep score. Kind of a big "oops" don't you think
 

CurtisOliver

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I was wrong on the dates, US date formats easily confuses things when you're used to reading dates the other way round.
So apologies on that.
 

RedCowboy

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The attitude is only manufactured in your mind GSS. Getting pissed off over nothing is not healthy.
Curtis you need to look at those dates. It clearly shows that I didn't revive the thread. I don't mind but a lot of people get real angry when others do. I was merely just acting on that.

Please don't spam my pm's redcowboy. Thankyou. Bad enough you "accidentally" gave me a bad rep score. Kind of a big "oops" don't you think
Coonie you messaged me and I responded to your PM, that's not spam, any moderator can check and see.

Coonie methinks is a troll, return banned member.
 
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Coonie you messaged me and I responded to your PM, that's not spam, any moderator can check and see.

Coonie methinks is a troll, return banned member.
Your last pm was just that dancing "6". Call me whatever names you want. At this point I'm done with this. There's nothing productive going on here. You started all of this too so don't take it out on me and I ain't no troll
 

RedCowboy

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Your last pm was just that dancing "6". Call me whatever names you want. At this point I'm done with this. There's nothing productive going on here. You started all of this too so don't take it out on me and I ain't no troll
That was the answer to your question, same as your answer to my question #6
 
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