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Conflicting information on divergence

kev532

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Hi lads, another newbie post here but after reading through this forum for days I still haven't found the answers I was looking for in past threads! I am relatively new to lasers and just have a few questions about divergence. Most of my lasers are just cheap eBay 532's apart from my 1W 445 Spartan which I have a few years now. When I received my first 532 from eBay I was amazed at the colour, bright beam, and especially the distance at which this laser threw a beam. I think after buying the Spartan I was really put off buying any more "high end" lasers because of the divergence. No doubt it's a well built and powerful laser but seeing that the beam dissipated after only 30 metres or so really defeated the purpose of having what I thought was to be a high end laser "pointer" and it has just been shelved ever since.
I have read through threads where people were trying to measure the earth curvature and members were suggesting that past 2km you need some kind of mega expensive lab laser setup to achieve a dot at that distance, but I have seen my cheap 532's do just that! On Sanwu's own website they advertise their 304 lasers to go a distance of 5, 10 and 15 km respectively. Why is there no mention of distance or even mrad specs on higher end lasers? I did contact Sanwu about my divergence concerns and Francis promptly replied advising me that low power lasers are low divergence and I had no need to worry about beam distance on the 100mw 492 pocket I was interested in so I have ordered it and now eagerly waiting to see. But for future reference and for anybody else looking to know I would really appreciate if someone could address this issue. As per Francis' advise, should I expect a 100mw 532 to outperform a 1W 532 on distance due to higher divergence of the higher power for example? I may order more wavelengths from sanwu but if power comes with the cost of divergence then I'm thinking I will just stick with the lower power pocket series, they're the perfect size anyway and I also have my eye on the 520. May trade my Spartan if anyone is interested!? Also, is divergence just relative to power or is wavelength also a factor? Have you guys got any recommendations on any other pocket sized lasers with the characteristics I am after? I would also like to note that while I do love a bright, far reaching beam, I am not interested in burning or buying beam expanders. My cheap 532's have the beam characteristics I like without expanders, I would just like a brighter beam and more options on wavelengths.

P.S. I know you guys like to know a bit about who you're talking to. I have visited the about section on my profile which says I have not supplied any additional information, but have not seen an option to edit this.
For anyone who would like to know, I am from Ireland, 33 years old, I do own a pair of safety glasses for the Spartan, and as may be apparent, I am mostly interested in bright beams, small size, and distance! Also, am not an idiot, I do not shine lasers at planes or houses or anything stupid like that, just a big kid who loves an impressive beam really!

Looking forward to any help/responses you guys might have
Thanks
Kev
 

steve001

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Good to see someone else that appreciates a low diverging beam. It all depends on the natural divergence of the diode. First thing you need to do is lower that divergence through beam shaping optics. But that's not possible with retail lasers. Such lasers need after market custom built parts. There are threads where folks have done that. Accomplish that and a beam expander isn't necessary, but it is a nice addition. Far too many are happy with a laser that only burns at close distance and couldn't care less that at distance the shape of the beam is a hugh rectangle.
 
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kev532

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Good to see someone else that appreciates a low diverging beam. It all depends on the natural divergence of the diode. First thing you need to do is lower that divergence through beam shaping optics. But that's not possible with retail lasers. Such lasers need after market custom built parts. There are threads where folks have done that. Accomplish that and a beam expander isn't necessary, but it is a nice addition. Far to many are happy with a laser that only burns at close distance and couldn't care less that at distance the shape of the beam is a hugh rectangle.
Thanks for the reply. Yea I'm not really into having another rectangle beam, though I did read there is a nice dot profile on the pocket series lasers so hopefully the one I have ordered will be as I expect. I don't know anything about optics and wouldn't know where to start building my own so just looking to buy without needing to modify.
 

paul1598419

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The difference between your 532nm laser and your 1 watt 445nm laser is the 532nm is a solid state laser which always have better divergence specs than a multi mode diode, like your 445nm laser. The higher the power of these direct diode lasers, the worse they diverge. You can tame that, to some extent, by using a beam expander. There are also cylindrical lens pairs made to help with this, but you need to build your laser to use them. The beam expander can usually be used with a purchased laser to help tame the divergence. Hope this helps you.
 
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SNIP

P.S. I know you guys like to know a bit about who you're talking to. I have visited the about section on my profile which says I have not supplied any additional information, but have not seen an option to edit this.
For anyone who would like to know, I am from Ireland, 33 years old, I do own a pair of safety glasses for the Spartan, and as may be apparent, I am mostly interested in bright beams, small size, and distance! Also, am not an idiot, I do not shine lasers at planes or houses or anything stupid like that, just a big kid who loves an impressive beam really!

Looking forward to any help/responses you guys might have
Thanks
Kev

If you go to the forum titled Welcome you can post there with information about who you are and where you are from.

As Paul posted different diodes diverge differently. As a rule store bought stuff has QC issues unless you go to the top tier stores. A lot of folks wind up building stuff because they can't buy what they want.

Here is a link to a youtube vid that may interest you. The guy is well known here and discusses not just divergence but wave length and beam expanders as well. Not to mention it is fun to watch.
 

cistercian

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Solid state lasers are fantastic, as are gas lasers for low divergence numbers. I have a 50 and 112mw 532 that have superior divergence over my diode lasers. I have a 10x beam expander which helps my high power diode lasers.
It depends on what you want to do. High power diodes are so inexpensive now they are a hoot to buy for burning at close range. For longer distance use or holograms solid state or gas lasers work much better. Some diodes are impressive though. I like the 405nm pointers that are dirt cheap. They have nice divergence characteristics.

I prefer diodes since they are inexpensive and powerful. I treasure my 532nm DPSS lasers for beam quality...but they are very temp sensitive. If you want max quality in the beam lab grade lasers are for you!

Best of luck to you and the community here won't steer you wrong!
 

cistercian

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Good to see someone else that appreciates a low diverging beam. It all depends on the natural divergence of the diode. First thing you need to do is lower that divergence through beam shaping optics. But that's not possible with retail lasers. Such lasers need after market custom built parts. There are threads where folks have done that. Accomplish that and a beam expander isn't necessary, but it is a nice addition. Far to many are happy with a laser that only burns at close distance and couldn't care less that at distance the shape of the beam is a hugh rectangle.
Or a line. Diodes are cool. The short dimension of the line is one wavelength tall on the die. The width of the line corresponds to the power...wider is more power. That being said, both have their place. Inexpensive high power diodes make impressive close range burners while much costlier gas and solid state DPSS lasers have much better divergence. I have painted cirrus clouds with my best 532nm DPSS laser, only 112mw. But blowing through plastic Folgers cans with 3.2 watts+ of 465nm is also amusing. Fortunately, either is available online.

I have a friend who has a 30w argon laser. Best of both worlds...but portable? Not so much!!!!!


Edited to add this incredibly ridiculous claim. The worst ever IMHO. Enjoy! https://www.laserpointerpro.com/uki...mable-laser-pointer-pen-kit-black-p-3805.html

Be sure to watch the video. The hilariousity is EPIC. OMG!!!!!!!!
 
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paul1598419

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This isn't the first 30 watt handheld laser I've seen advertised by a Chinese seller. To get even 1 watt of 532nm would require a pump diode of ~5 watts of optical power. Because the waste heat is so difficult to remove from a pointer, you don't see 1 watt 532nm pointers in reality very often or for less than $800.00. That dinky little pointer has less heat sinking than a 501B host does. It likely doesn't put out more than 90 mW. I still have a few 200 mW 532nm modules in my stock that I bought several years ago. I've been thinking of using one in a new pointer build as I have a host that would take it easily, but the run time will likely be limited to 60 seconds.
 

kev532

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Thank you all for all the information provided. I will look into gas, dpss and all these other options when I get a chance, I will also visit the welcome section and add some details. I am away with the missus this weekend and will only get a slap for being "more interested in lasers" at the moment :D Thanks again :)
 

steve001

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This isn't the first 30 watt handheld laser I've seen advertised by a Chinese seller. To get even 1 watt of 532nm would require a pump diode of ~5 watts of optical power. Because the waste heat is so difficult to remove from a pointer, you don't see 1 watt 532nm pointers in reality very often or for less than $800.00. That dinky little pointer has less heat sinking than a 501B host does. It likely doesn't put out more than 90 mW. I still have a few 200 mW 532nm modules in my stock that I bought several years ago. I've been thinking of using one in a new pointer build as I have a host that would take it easily, but the run time will likely be limited to 60 seconds.
A long time ago when I had access to the necessary tools I built a host from brass nipples.
 

hakzaw1

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You OP is a brick. & hard to read.

instead of this:

Hi lads, another newbie post here but after reading through this forum for days I still haven't found the answers I was looking for in past threads! I am relatively new to lasers and just have a few questions about divergence. Most of my lasers are just cheap eBay 532's apart from my 1W 445 Spartan which I have a few years now. When I received my first 532 from eBay I was amazed at the colour, bright beam, and especially the distance at which this laser threw a beam. I think after buying the Spartan I was really put off buying any more "high end" lasers because of the divergence. No doubt it's a well built and powerful laser but seeing that the beam dissipated after only 30 metres or so really defeated the purpose of having what I thought was to be a high end laser "pointer" and it has just been shelved ever since.
I have read through threads where people were trying to measure the earth curvature and members were suggesting that past 2km you need some kind of mega expensive lab laser setup to achieve a dot at that distance, but I have seen my cheap 532's do just that! On Sanwu's own website they advertise their 304 lasers to go a distance of 5, 10 and 15 km respectively. Why is there no mention of distance or even mrad specs on higher end lasers? I did contact Sanwu about my divergence concerns and Francis promptly replied advising me that low power lasers are low divergence and I had no need to worry about beam distance on the 100mw 492 pocket I was interested in so I have ordered it and now eagerly waiting to see. But for future reference and for anybody else looking to know I would really appreciate if someone could address this issue. As per Francis' advise, should I expect a 100mw 532 to outperform a 1W 532 on distance due to higher divergence of the higher power for example? I may order more wavelengths from sanwu but if power comes with the cost of divergence then I'm thinking I will just stick with the lower power pocket series, they're the perfect size anyway and I also have my eye on the 520. May trade my Spartan if anyone is interested!? Also, is divergence just relative to power or is wavelength also a factor? Have you guys got any recommendations on any other pocket sized lasers with the characteristics I am after? I would also like to note that while I do love a bright, far reaching beam, I am not interested in burning or buying beam expanders. My cheap 532's have the beam characteristics I like without expanders, I would just like a brighter beam and more options on wavelengths.

P.S. I know you guys like to know a bit about who you're talking to. I have visited the about section on my profile which says I have not supplied any additional information, but have not seen an option to edit this.
For anyone who would like to know, I am from Ireland, 33 years old, I do own a pair of safety glasses for the Spartan, and as may be apparent, I am mostly interested in bright beams, small size, and distance! Also, am not an idiot, I do not shine lasers at planes or houses or anything stupid like that, just a big kid who loves an impressive beam really!
YOU-- could have posted it like this:


Hi lads,

another newbie post here but after reading through this forum for days I still haven't found the answers I was looking for in past threads! I am relatively new to lasers and just have a few questions about divergence. Most of my lasers are just cheap eBay 532's apart from my 1W 445 Spartan which I have a few years now.

When I received my first 532 from eBay I was amazed at the colour, bright beam, and especially the distance at which this laser threw a beam. I think after buying the Spartan I was really put off buying any more "high end" lasers because of the divergence. No doubt it's a well built and powerful laser but seeing that the beam dissipated after only 30 metres or so really defeated the purpose of having what I thought was to be a high end laser "pointer" and it has just been shelved ever since.

I have read through threads where people were trying to measure the earth curvature and members were suggesting that past 2km you need some kind of mega expensive lab laser setup to achieve a dot at that distance, but I have seen my cheap 532's do just that! On Sanwu's own website they advertise their 304 lasers to go a distance of 5, 10 and 15 km respectively. Why is there no mention of distance or even mrad specs on higher end lasers?

I did contact Sanwu about my divergence concerns and Francis promptly replied advising me that low power lasers are low divergence and I had no need to worry about beam distance on the 100mw 492 pocket I was interested in so I have ordered it and now eagerly waiting to see. But for future reference and for anybody else looking to know I would really appreciate if someone could address this issue. As per Francis' advise, should I expect a 100mw 532 to outperform a 1W 532 on distance due to higher divergence of the higher power for example? I may order more wavelengths from sanwu but if power comes with the cost of divergence then I'm thinking I will just stick with the lower power pocket series, they're the perfect size anyway and I also have my eye on the 520.

May trade my Spartan if anyone is interested!? Also, is divergence just relative to power or is wavelength also a factor? Have you guys got any recommendations on any other pocket sized lasers with the characteristics I am after? I would also like to note that while I do love a bright, far reaching beam, I am not interested in burning or buying beam expanders. My cheap 532's have the beam characteristics I like without expanders, I would just like a brighter beam and more options on wavelengths.

P.S. I know you guys like to know a bit about who you're talking to. I have visited the about section on my profile which says I have not supplied any additional information, but have not seen an option to edit this.
For anyone who would like to know, I am from Ireland, 33 years old, I do own a pair of safety glasses for the Spartan, and as may be apparent, I am mostly interested in bright beams, small size, and distance! Also, am not an idiot, I do not shine lasers at planes or houses or anything stupid like that, just a big kid who loves an impressive beam really!

^^ much easier on the eyes^^^

do no give up on doing a proper job with your profile....
AND please read the intros placed by others in the welcome section..\
we will NOT remember where you are from-- so that needs to be IN your profile --like mine is..
click on my username and there it is!!! TEXAS
also do you understand what w and W stand for--how about mw-mW Mw and MW--are they all the same --no way.

awaiting your intro thread.. hak
 

kev532

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Thanks guys, lots of great info there, I will keep reading and continue to learn through the forum. Will most likely hit the buy/sell/trade section to see if I can commission a build from one of the members with a lot more knowledge and resourses than myself as I would love something in the 510-515nm spectrum but have not yet come across anything I've wanted to buy.


Here is a link to a youtube vid that may interest you. The guy is well known here and discusses not just divergence but wave length and beam expanders as well. Not to mention it is fun to watch.[/QUOTE]

Haha, thats a great video, very informative too, thanks for that ragebot.
 




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