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CE5

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:whistle:
 

CE5

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@NeedDistance, I'm standing by- if you would prefer to continue via private message that would be fine.
 

Alaskan

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I've studied long distance beaming for four years now, have a few thoughts on the matter for great distances far beyond our atmosphere:

1550 nm is a good clear low loss atmospheric window, but so are these, look me a long time to find this graph, I marked it for areas of the spectrum I think are good choices to use. With the exception of 1025 nm, the red lines are for laser wavelengths we can easily find or get. For 1065 nm use a 1064 nm ND:YAG:



My thought is a 1064 nm YAG is one of the best choices for short nanosecond high energy pulses due to the high energy available fairly cheaply, and low atmospheric loss in that part of the spectrum. It's not a VIS wavelength, of course, and most cameras sensitivity drops off up at that end of the spectrum, but I believe the power available more than makes up for it for instrumental detection and data transmission too. For data transmission finding a way to modulate it is the trick, due to a YAG producing short narrow pulses, but I have a few ideas.

All of that aside, who is out there to talk to? The ISS? I don't think they care about one individual wanting to flash them. Although I am sure the day will come when this will become more important for us, as we begin to move out into the great beyond. If you are going to do some atmospheric work IR is a probably a good choice if expanded to a wide beam for two reasons, less chance of harming someone when expanded (although at YAG intensities, I don't think that holds true, but if expanded a great amount reduces it) and due to being IR, the FAA won't come after you for beaming into the sky, what they don't know won't hurt them. Although some law enforcement aircraft can see the beam with their video equipment, so a good idea not to point at aircraft for any reason, even if IR, especially a YAG!
 
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CE5

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It would be swell, if more interest could be generated here on LPF concerning FSO-free space optical, communication applications. ;)
 

Encap

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It would be swell, if more interest could be generated here on LPF concerning FSO-free space optical, communication applications. ;)

"NASA is developing a trailblazing, long-term technology demonstration of what could become the high-speed internet of the sky.
The Laser Communications Relay Demonstration (LCRD) will help NASA understand the best ways to operate laser communications systems. They could enable much higher data rates for connections between spacecraft and Earth, such as scientific data downlink and astronaut communications."

See: https://phys.org/news/2017-03-nasa-high-speed-space-internet.html
 
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WOW!
Thanks very much guys/?gals for your great advice and interest. I'll have to look up a lot of what you've said! I'm a newborn to all of this. I'm a bit busy, right now, but I'll try to reply, somewhat briefly, below, in summary. I hope this covers everyone ...
'CE5' -
your name alone and suspicious whistling gives you away lol
Nice to meet a fellow traveller on here :)
My interest is indeed EBE contact. I don't really need to go private messaging because I have had 'experiences', even with other people, so I'm very sure of what I'm saying and I've nothing to hide. However, I would like to be considered as a serious-minded person on this forum (which I am) in order to learn from others. Thus, if I was only being sneered at, by everyone, I would simply close my current account and open a new one. I don't feel the need to 'prove' my beliefs but I also don't want any negative drama in my life (i.e. I don't have the desire to battle with trolls). This is personal for me, which is why I'm doubting the whole CE-5 Initiative: I choose to seek alone, or with a few close friends, because egos get in way of proper communication, and there are too many egos flying about in a group of strangers (the CE-5 Initiative). I also doubt anything - religion, cults, whatever - that involves money being gained by someone at the top. Moreover, many involved in CE-5 have never had any 'experiences' and I'm wondering if that's because they weren't 'chosen'. I've had sightings all my life, so I must ask 'why me, and not you?'
Also, I was wondering if ET are sick of humans trying to take pics/vids of their ships, just to impress or prove to some other humans. The phenomenon is 'hiding' and if we enforce exposure on it, they may simply say 'bye' to us, as individuals. With CE5, it all seems like a lot of cameras clicking, OTT whooping and egos flying all over the place. RE the taking pics/vids: I got my answer to this, only yesterday. I 'asked' for a daytime sighting and I got it, quite high up in a wide expanse of blue sky but definitely 'not human'. Like everyone else, I grabbed for my camera, but by the time I got it out, the object had disappeared. No human aircraft could have moved that fast out of the view I had. I cursed myself because I felt I had messed up the sighting by fiddling with my mobile phone. Then, a moment later, and much further away, I saw a similar 'shape', maybe the same one (maybe it had 'travelled', a great distance). Foolishly, I went for my camera again and, like the last time, it was gone by the time I looked up. I can take a hint so, obviously, I'll never be reaching for my camera again. I want real contact, not just lights in the night-sky - i.e. I don't need to impress Facebook.
I will check out your Space thread, eventually. Don't forget that the Perseid Meteor Shower is on tonight :)
'Alaskan' -
It seems like you are me, four years in the future, hopefully. It'll take me some time understanding all you're saying - I'm really new to all of this. But I do think that I may be coming back to you, again and again, for your guidance. Thank you for all those details - weekend reading is settled, then :)
Encap -
Thanks for more interesting developments from NASA and astronomers. Some really interesting stuff you're posting here. Much appreciated.

If anyone comments, I'm sorry if I don't reply immediately - what with the Perseid Meteor Shower etc, I've a very busy weekend, ahead. I'm not being rude nor am I being a 'tldr' tosser lol.
 

Alaskan

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What I learned in a nut shell:

You don't need high power if you can get a low divergence laser diode which has a tiny emitter and expand it, they can be only a couple hundred milliwatts if single mode and produce a beam which can stay in a relatively tight beam to be viewed as the brightest spot of light coming from the earth (if you are away from other light sources so it can stand out). However, if the beam is uber tight, it is also uber difficult to put on a target too, perhaps too difficult.

Here's what I'd do, I'd mount and align a low divergence IR laser diode which has been expanded to a few inches diameter directly on a telescope, mount it right on top of the telescope so you can spot properly. Alignment is going to be extremely tedious and might not work out very well for extremely long distances over a couple hundred miles, but I haven't researched that aspect well enough to give advice on it.

You can also use a high power source (which I just said isn't necessary) and get the same low divergence of a single mode low power diode by expanding the beam to a very wide beam. Doing so can produce a beam just as tight as an extremely low divergence diode, but with more power. However, still difficult to put the spot on something because the output won't be very wide a long distance away.

If you want to attract something out there, might be better to use a 1064 nm YAG laser, expand the output as wide as you can and then collimate it. After that put a large number of optical line rods in front of the collimated beam, just stack them to cover the entire output. Now you will have most of the power converted into several laser lines and can sweep a very large area without missing your target, that is, if you want to make a beacon. The power which will land on the target will be extremely reduced, but if you are using a YAG laser with several million watts of peak power all packed into nanosecond pulses, I think it might still show up at the distant end as a very bright source, even if 100 or more miles away.

What I don't know is how safe this is, it might not be safe, might not be at all advisable. If you hit someone close by, especially since it would be a wide line, it could blind someone. So, I don't advise doing something like that until you have had a professional run the numbers to give you a good idea how hazardous the beam could be to someone close by, or within a mile or more distant etc. Off the top of my head, I'd guess this is very hazardous as well as illegal. Maybe this isn't a reasonable project to build, maybe too dangerous, I just don't know. However this might produce a flash of IR light which can be viewed from extreme distances and then you don't have the trouble of trying to target something with a very tight beam which is nearly impossible to put on something and keep it on it if they are moving, or even if stationary, when very far away.

Maybe better not to go the YAG route, you could however use the same concept with a single mode laser diode which has much lower power and constant, instead of a short pulse. Just expand the output as big as you can get it and put a bunch of line producing rod lenses in front. You could make a fairly small hand held laser pointer to do this with, but I don't know I would build something like this in the visible spectrum. Expanding the beam will produce a very low divergence output, putting a line lens in front will produce a line which expands very little in thickness as it travels forward and you would be certain to be flashing a lot of aircraft out there which is illegal. Would the line be weak enough it doesn't matter? If it is that weak, then it isn't effective for your use either, but if you can get enough power at IR into a line being produced from a uber low divergence beam, it might work, but still hazardous close up, I am sure.

Some membeers will certainly caution you against doing this, I am too, but wanted to share some ideas, might be work arounds so it can be done safely, but the beam will need to be expanded to a huge diameter to reduce the power density to be safer.
 

Encap

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What I learned in a nut shell:

You don't need high power if you can get a low divergence laser diode which has a tiny emitter and expand it, they can be only a couple hundred milliwatts if single mode and produce a beam which can stay in a relatively tight beam to be viewed as the brightest spot of light coming from the earth (if you are away from other light sources so it can stand out). However, if the beam is uber tight, it is also uber difficult to put on a target too, perhaps too difficult.

Here's what I'd do, I'd mount and align a low divergence IR laser diode which has been expanded to a few inches diameter directly on a telescope, mount it right on top of the telescope so you can spot properly. Alignment is going to be extremely tedious and might not work out very well for extremely long distances over a couple hundred miles, but I haven't researched that aspect well enough to give advice on it.

You can also use a high power source (which I just said isn't necessary) and get the same low divergence of a single mode low power diode by expanding the beam to a very wide beam. Doing so can produce a beam just as tight as an extremely low divergence diode, but with more power. However, still difficult to put the spot on something because the output won't be very wide a long distance away.

If you want to attract something out there, might be better to use a 1064 nm YAG laser, expand the output as wide as you can and then collimate it. After that put a large number of optical line rods in front of the collimated beam, just stack them to cover the entire output. Now you will have most of the power converted into several laser lines and can sweep a very large area without missing your target, that is, if you want to make a beacon. The power which will land on the target will be extremely reduced, but if you are using a YAG laser with several million watts of peak power all packed into nanosecond pulses, I think it might still show up at the distant end as a very bright source, even if 100 or more miles away.

What I don't know is how safe this is, it might not be safe, might not be at all advisable. If you hit someone close by, especially since it would be a wide line, it could blind someone. So, I don't advise doing something like that until you have had a professional run the numbers to give you a good idea how hazardous the beam could be to someone close by, or within a mile or more distant etc. Off the top of my head, I'd guess this is very hazardous as well as illegal. Maybe this isn't a reasonable project to build, maybe too dangerous, I just don't know. However this might produce a flash of IR light which can be viewed from extreme distances and then you don't have the trouble of trying to target something with a very tight beam which is nearly impossible to put on something and keep it on it if they are moving, or even if stationary, when very far away.

Maybe better not to go the YAG route, you could however use the same concept with a single mode laser diode which has much lower power and constant, instead of a short pulse. Just expand the output as big as you can get it and put a bunch of line producing rod lenses in front. You could make a fairly small hand held laser pointer to do this with, but I don't know I would build something like this in the visible spectrum. Expanding the beam will produce a very low divergence output, putting a line lens in front will produce a line which expands very little in thickness as it travels forward and you would be certain to be flashing a lot of aircraft out there which is illegal. Would the line be weak enough it doesn't matter? If it is that weak, then it isn't effective for your use either, but if you can get enough power at IR into a line being produced from a uber low divergence beam, it might work, but still hazardous close up, I am sure.

Some membeers will certainly caution you against doing this, I am too, but wanted to share some ideas, might be work arounds so it can be done safely, but the beam will need to be expanded to a huge diameter to reduce the power density to be safer.
The problem with it is NeedDistance's budget for such an activity----keep in mind the OP only had funds for this lowest level quality and output mass produced laser 303, see: 10 miles Green + Star Cap 5MW 532NM Laser Pointer Pen Lazer Light Beam Zoom Burn | eBay based on typical Chinese reseller misrepresentations as too distance and output.

I doubt anyone even imagines any ability to contact people, places or things in space with minimum quality and output, mass produced laser 301 303, or 305/just generic toy quality 532nm laser costing almost nothing --$5-$15.

Many $1000s of dollars or more on a hope, wish, and dream chase, in this case, are probably out of the question.
 
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Alaskan

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I agree, the cost and time required to do something like this right probably keeps us all safe :)
 

Alaskan

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I've seen some craft I thought were alien, so advanced I was sure they were, but they could be ours, we very well may have secret advanced anti-gravity vehicles which regardless of being secret, are flying around a lot, hovering over cities and making a show of themselves :p



All of the vets here know my position on this subject, personally I think there must be a way to travel through space without being limited by our theory of nothing with mass being able to travel near, or beyond the speed of light, but warp space and you are not violating that law. Doesn't matter if what I think is correct, I simply don't know anything in regard to these things for sure, but I can guess.
 
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ArcticDude

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steve001

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It would be swell, if more interest could be generated here on LPF concerning FSO-free space optical, communication applications. ;)
But what's more productive, building or buying high power lasers just so one can burn stuff or building or buying a laser for optical communication and other technical applications? When the average forum demographic appears to be young male adults what is more likely, the former or the latter?
 

steve001

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What I learned in a nut shell:

You don't need high power if you can get a low divergence laser diode which has a tiny emitter and expand it, they can be only a couple hundred milliwatts if single mode and produce a beam which can stay in a relatively tight beam to be viewed as the brightest spot of light coming from the earth (if you are away from other light sources so it can stand out). However, if the beam is uber tight, it is also uber difficult to put on a target too, perhaps too difficult.

Here's what I'd do, I'd mount and align a low divergence IR laser diode which has been expanded to a few inches diameter directly on a telescope, mount it right on top of the telescope so you can spot properly. Alignment is going to be extremely tedious and might not work out very well for extremely long distances over a couple hundred miles, but I haven't researched that aspect well enough to give advice on it.

You can also use a high power source (which I just said isn't necessary) and get the same low divergence of a single mode low power diode by expanding the beam to a very wide beam. Doing so can produce a beam just as tight as an extremely low divergence diode, but with more power. However, still difficult to put the spot on something because the output won't be very wide a long distance away.

If you want to attract something out there, might be better to use a 1064 nm YAG laser, expand the output as wide as you can and then collimate it. After that put a large number of optical line rods in front of the collimated beam, just stack them to cover the entire output. Now you will have most of the power converted into several laser lines and can sweep a very large area without missing your target, that is, if you want to make a beacon. The power which will land on the target will be extremely reduced, but if you are using a YAG laser with several million watts of peak power all packed into nanosecond pulses, I think it might still show up at the distant end as a very bright source, even if 100 or more miles away.

What I don't know is how safe this is, it might not be safe, might not be at all advisable. If you hit someone close by, especially since it would be a wide line, it could blind someone. So, I don't advise doing something like that until you have had a professional run the numbers to give you a good idea how hazardous the beam could be to someone close by, or within a mile or more distant etc. Off the top of my head, I'd guess this is very hazardous as well as illegal. Maybe this isn't a reasonable project to build, maybe too dangerous, I just don't know. However this might produce a flash of IR light which can be viewed from extreme distances and then you don't have the trouble of trying to target something with a very tight beam which is nearly impossible to put on something and keep it on it if they are moving, or even if stationary, when very far away.

Maybe better not to go the YAG route, you could however use the same concept with a single mode laser diode which has much lower power and constant, instead of a short pulse. Just expand the output as big as you can get it and put a bunch of line producing rod lenses in front. You could make a fairly small hand held laser pointer to do this with, but I don't know I would build something like this in the visible spectrum. Expanding the beam will produce a very low divergence output, putting a line lens in front will produce a line which expands very little in thickness as it travels forward and you would be certain to be flashing a lot of aircraft out there which is illegal. Would the line be weak enough it doesn't matter? If it is that weak, then it isn't effective for your use either, but if you can get enough power at IR into a line being produced from a uber low divergence beam, it might work, but still hazardous close up, I am sure.

Some membeers will certainly caution you against doing this, I am too, but wanted to share some ideas, might be work arounds so it can be done safely, but the beam will need to be expanded to a huge diameter to reduce the power density to be safer.
I've done something similar. I've attached my laser to a spotting scope. I had to come up with a mount to center the beam incrementally.
 

Benm

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Really, the best option you are going to have is to get a DPSS 532 then. It won't be as bright as a 520 at night, but the divergence of a 532 will more then make up for it on distance vs the 520.

Both have been demonstrated by obserations from the ISS afaik.

The lower divergence beam from the dpss 532 nm would certainly help, but you'd also need to be aiming more precisely to gain from it. This is not trivial considering the orbital speed of the ISS - it moves from one horizon and disappears behind the order in minutes.
 




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