Laser Grid - How?

[Laserblast]

First of all, i want to clarify:
I searched the forum, not finding answers to this case
I love lasers, but, curently my level of knowledge, about this subject, is low, sorry, if i say stupid things.
English is not my mothertongue, i hope you understand.

I need your help for:
I want to realize, a Green laser gate/grid, as a portal, between two rooms,
The effect i want to get is this

but i would be satisfied with just that

-Must be well visible, with light on, or at least suffused, no fog/smoke
-Size of the grid 4x3m 13x9Ft
-The grid would be still
-No one will have to go through it, then, i don't care whether it's safe for the eyes or not.
-I have few finances, i wish to do it, spending as little as possible
-If possible, using just one laser.

Question:
1- Can i achieve my goal, using just one laser? maybe usign some kind of prism splitters? or fiber optic splitter?

2- If i'm not mistaken, the laser beam, loses brightness, power, with each refraction?
Is there any kind of trick to reduce the loss? some kind of coated prism/mirror, as SiMirror?

3- A 350-500mW green laser diodes, would be fine? EDIT [I notice only now, i wrote 35-50mW...dunno why, i mean 350-500mW]

4- Which laser do you advise me to buy, which is "the cheapest", even if chinese, with dispersion.

I thank you in advance for the help you will give me.

 

[paul1598419]

A laser grid is easy to make with a single laser. You use crossed diffraction gratings of ~300 lines/mm. You can just buy the diffraction gating for a grid on eBay instead. But, you can't make light reflect of of air to make a portal. It has to have something there to reflect off of to see it.

 

[Laserblast]

Correct me if I'm wrong, but, this way, i obtain a starting beam from a single point, fanned out?
I want parallel rays, as seen in the examples.

let me explain better, the portal to be covered with the laser grid, it exists physically, on the sides of it, I can glue reflective surfaces, and in the wall I can embed lasers, and various electronics.

I want to get an effect more similar to that of videos, but I just don't understand, if they used splitters, fiber optics, or individual laser diodes for each beam. Or what is the most economical method

 

[paul1598419]

The second video just uses green lasers in a fog to make them more visible, but you run the risk of eye damage if you pass through them and get hit in the eye by one. Your grid could be done this way, but still has these problems.

 

[ArcticDude]

Correct me if I'm wrong, but, this way, i obtain a starting beam from a single point, fanned out?
I want parallel rays, as seen in the examples.

let me explain better, the portal to be covered with the laser grid, it exists physically, on the sides of it, I can glue reflective surfaces, and in the wall I can embed lasers, and various electronics.

I want to get an effect more similar to that of videos, but I just don't understand, if they used splitters, fiber optics, or individual laser diodes for each beam. Or what is the most economical method

Yes, diffraction grating will cause "fan effect"

 

[Laserblast]

Waoooooo @Articdude Nice photo!!!

I think, (fault of youtube videos) you missed a portion of my first post,
Anyway, blindness is not a problem as i said

I have a wall, between two rooms, with a free passage, no phisical door.
I want to create a gate effect inside this passage.
Maybe these splitters could be fine? the light is refracted at a 90° angle, and continues forward.
But, To do what I want, i need at least, a dozen of them, a single beam can be enough? or does it weaken too much?
According to the video, how on earth, they did that effect?

 

[phosphoressential]

You could do it with beamsplitters but you'd have to have a bunch of different ones that let through different fractions of the beam. Otherwise you get a strong beam from the first cube and less and less going through more.

Diffraction grating does just fan it out, but if you put the laser on the ceiling and position it so that the fanned beams line up with the door, then put a mirror (/some mirrors) above the door reflecting the beams down across the doorway. I think that's probably the easiest and cheapest way to do this.

The pros will just have a bunch of individual diodes. Like both of those videos. Notice how the second one the lasers are the only thing lighting the room haha. More power more betta less aligny

 

[Laserblast]

Dude! Brilliant, thanks for the sketch.
At this point, as you said, more mirrors, instead of a single one, otherwise, the angle would be busted, with more mirrors instead, i can straighten every single ray.
Can you recommend a "Diffraction grating" to buy? That has undergone a strong refraction angle. In this way i can keep the distance between rays and mirrors as short as possible (I don't have much space on the portal)

To avoid using smoke machines, a 35mW or 50mW, should it have a visible minimum radius right? or better to buy a more powerful one?

Yes, the second video is...radioactive!!!

Thanks a lot

 

[phosphoressential]

Dude! Brilliant, thanks for the sketch.
At this point, as you said, more mirrors, instead of a single one, otherwise, the angle would be busted, with more mirrors instead, i can straighten every single ray.
Can you recommend a "Diffraction grating" to buy? That has undergone a strong refraction angle. In this way i can keep the distance between rays and mirrors as short as possible (I don't have much space on the portal)

To avoid using smoke machines, a 35mW or 50mW, should it have a visible minimum radius right? or better to buy a more powerful one?

Yes, the second video is...radioactive!!!

Thanks a lot

Hahah oh doiiiii. Spot on good sir! Not much harder tho as you probably won’t need too many beams. I’ve had a lot of trouble finding gratings online honestly. I bought a couple different thicknesses of this stuff

Amazon.com

It’s not super great under a microscope but it does the job. You could mask off beams in one direction to get a single fan. Might be hard to mask very close to the grating. Wish I knew the divergence angle for green on it but I can’t remember what it’s like

 

[Encap]

As Paul mentioned --projecting on a wall is one thing --- your doorway gate in air is another.

Would be expensive and dangerous--would require more powerful potentially eyesight damaging lasers .
Would be a pathetic version with a 50mW laser and no fog--waste of money and time.

Maybe contact lasertech.in at enquiry@lasertech.in and ask how they did the green square entry grid in the video and what the cost equipment to do the same effect would be.

See: https://laserpointerforums.com/threads/square-laser-grid.102053/

 

[phosphoressential]

Lol y’all are very god about your warning people about safety. I don’t have enough time in the day to earn every last person about where they point their dong.

Encap, you’re for sure right that with no fog you’re SOL. But creating the effect is for sure possible. Laserblast, don’t let the nancies block your creativity. They don’t know anything about your use case, as you haven’t told any of us ¯\_(ツ)_/¯ and are just giving advice based on the largest community that might see it because it’s morally defensible to the end. Go out and Make my brother! And be safe! That responsibility does not transfer to others on the internet. You gotta do it. If this was a gun forum no one would expect everyone to just warn each other about gun safety 24/7. Some of these OG members are so negative about anyone they don’t know saying anything as they assume the worst about you.

 

[Laserblast]

As Paul mentioned --projecting on a wall is one thing --- your doorway gate in air is another.
Would be expensive and dangerous--would require more powerful potentially eyesight damaging lasers .
Would be a pathetic version with a 50mW laser and no fog--waste of money and time.
Maybe contact lasertech.in at enquiry@lasertech.in and ask how they did the green square entry grid in the video and what the cost equipment to do the same effect would be.
See: https://laserpointerforums.com/threads/square-laser-grid.102053/

Thanks, logically...Contacting, those who made those laser cages, was the first thing i did.
After 4 months without answer, i ask on this forum.

It seems clear...that the grid projected in 2D which you others, keep mentioning, and my Grid/Gate, in a 3D space (As mentioned in my msgs, accompanied by clear video examples), were two different things, in fact ...
-I never asked, about a grid projected on a wall ...
-I never asked to project a grid into air air, "without any physical or reflective support". (I have mentioned the prisms several times)
-I have clarified several times that, "saferty is not relevant in this single case" because... I repeat once again, no living being, will NEVER
pass by, or near, my lasers!

My text request, and the video example were clear, on my intent.
You have been very kind, to respond immediately, i appreciated it, but, IMHO it seems that, some, don't waste much time reading the true meaning of the questions, it's a common thing on the web these days, few people stop and answer what is asked, many instead tend to answer what they suppose to have been asked.
Luckily @phosphoressential and @ArcticDude, they stopped to read my post, kudos!


My bad?..I thought i was quite responsible, defining, low, my level of knowledge on lasers. But, from the many recommendations...I suppose i appeared, as... A redneck, with a granade, or worse, a sociopath escaped from the asylum with the murderous intent to mount a "Rheinmetall 50kW laser" on the roof of his van, ready to conquer the world.

...Just to know, they've already taught me that, the pots on the stove, should not be touched with bare hands, i have also learned that putting metal objects in the socket is not good.
The next time i have a question, i make a cad diagram ...

Fun aside, i'm waiting for someone to recommend a store link, where to buy a laser for my purpose, but please not too expensive. I repeat, also a chinese one from Aliexpress or Banggood, if really have the power intensity, described!
Please No Wickedlaser, i have a Nano 75mW, it's "cute" but...their price...

 

[ArcticDude]

You can google for "8 beam laserbar" but those can be a bit pricey but you can also fine "4 beam laserbars" at 198€

💡 Eurolite LED Multi FX Laser Bar

LED Multi FX Laser Bar Matrix effect with a total of 192 LEDs offers changing RGBAW patterns, 2x UV-LED (3 W) for black light effects, 36 Cool white SMD LEDs (0.5 W) for fast, dynamic strobe effects, 4 Laser diodes project thousands of red and...

www.thomann.de

EDIT

10 Beam laserbar at 1086$

1085.69US $ |1000mw 10 Eyes / 10 Heads Green Laser Curtain Light Parallel Laser Bar Light Dmx Portable For Event Party Stage Dj Equipment - Stage Lighting Effect - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[Laserblast]

Tnx.
You won't belive it but... i'm on aliexpress rightnow, i found the same stuff, but via searching, Laser array!
Unfortunately, they cost a lot, and, from what i read, the 200$ version, are weak, it need complete darkness to bee seen, the description says 1w.... i don't belive it, also because, lasers for dance floor, should have a low class, but being Chinese... dunno. The last one is very expansive for my pockets, currently.


edit:
I think i should buy a pointer, or a diodes (1w or 1.5w will it be enough?) an heatsink, a diffraction grating, and arm myself with a soldering iron, but i don't know which one, which doesn't cost too much.

 

[kecked]

Since no one is going through the gate can you put clear plastic up over the opening to project onto? Now you can use a regular video projector. The best way to do it is with a fog curtain. You could also haze the entire space. Another safe way would be to use side emitting fiber and weave the grid. Now people could actual go through it pushing it to one side. Laser by itself in air isn’t going to show well even with fog and the lights on unless your in the high 500mw range for each beam. Put the hazer in the room behind the opening and blow it through with a fan. Haze is nearly invisible if done well.

You could also employ a proximity sensor or three so that if someone gets within say three feet Ie arms length of the opening it shuts off.

 

[Laserblast]

Tnx kecked but, i want use laser.

Perhaps if i use a 1W laser, with the diffraction grating, and then using mirros (as said by phosphoressential) could the rays be visible in soft light?

I notice an error in my first msg i write 35-50mW...dunno why, but i mean 350-500mW