5X Beam Expander Jetlasers

Hey all

I want to tell something about the beam expanders for lasers and show some pictures too. I bought this 5X BE from Jetlasers GB. It was discounted and was shipped together with my Ti-B green laser. I hadn't a particular reason to chose a 5X BE. The 10X BE was huge and so I ended ordering a 5X BE.

I quote a text from Melles Griot.

In its broadest sense, a beam expander is any optical system designed to increase the diameter of a laser beam. In most cases, the term is taken to mean a telescope designed to take a small-diameter collimated beam input beam and produce a larger diameter collimated output beam, thus reducing the divergence of the beam. There are two basic types of simple beam expander. The Keplerian beam expander consists of a positive input lens and a positive objective, the Galilean beam expander consists of a negative input lens and a positive objective. In both cases, the expansion factor is the ratio of the focal length of the two lenses. The advantage of the Keplerian expander is the ability to use it with a spatial filter to clean up the beam. The advantage of the Galilean expander is its short length for a given magnification and clear aperture.

Click to expand...

So BE are used for reducing the divergence at a cost of wider beam at the exit aperture. Here are my pictures.

The BE was delivered with dustcaps on both sides


No moving part, just one piece of optical instrument.


AR coating on the exit lens.


The entrance lens has also AR coating. It is the same coating as on the front. It is difficult to see in the picture.


Included are two adapters for 13.6mm and 36.0mm


I ditch the metal setscrews and replace them with black nylon screws.
They don't marred the laser.


The BE on the standard penlaser. Big head for small laser.


That is more like it !




The Jetlaser DPL-700 beam in the sky. The photo was taken with a Canon 300mm/F4 L telelens.


Same camera setting with the 5X BE mounted. Much better divergence.


Tree shot at 85 meter. Without the BE.


With the 5x BE


More pictures coming like beam thickness at the aperture.
I hope you like it so far. :thanks:

Awesome review! Good information on beam expanders.

Can you do a beam size comparison (measurement) at output with a typical green laser? I'd like to see if it'd be a good thing to add to a projector for matching the size of the green laser beam to the other lasers.

That is awesome.. I bet this would be fun to play with , in long range pointing :beer:

Bionic-Badger said:

Can you do a beam size comparison (measurement) at output with a typical green laser? I'd like to see if it'd be a good thing to add to a projector for matching the size of the green laser beam to the other lasers.

Click to expand...

The Skylasers DPL-700 isn't a typical laser. The beam thickness at aperture is 5-6mm wide. With the BE it becomes almost an inch thick.
You want ~3mm to match the red laser in the projector ?

With that 300mm lens I bet you can get a nice shot of the beam on an object at a pretty good distance.
Do you have any hills, mountains, or unoccupied construction sites nearby?
With that laser and the beam expander 5 miles (8km) should be no problem.

Hi Blord

Nice review :beer: and pictures.

Q: How much mW does the expander eat away.

RA_pierce said:

With that 300mm lens I bet you can get a nice shot of the beam on an object at a pretty good distance.
Do you have any hills, mountains, or unoccupied construction sites nearby?
With that laser and the beam expander 5 miles (8km) should be no problem.

Click to expand...

Alas, I live in an area that so flat as a ruler.
No skyline too, only trees and houses.
I could try the moon but I don't see the dot on the surface.

Smeerworst said:

Hi Blord

Nice review :beer: and pictures.

Q: How much mW does the expander eat away.

Click to expand...

Thanks

That would pose a problem. The dot is so wide that I can't measure at close distance. The dot is bigger than the sensor.
I will try again with a smaller focused dot on distance.

Thanks for the info and nice pics. A little jealous of your 700 mW... :beer:

Blord said:

The Skylasers DPL-700 isn't a typical laser. The beam thickness at aperture is 5-6mm wide. With the BE it becomes almost an inch thick.
You want ~3mm to match the red laser in the projector ?

Click to expand...

Yeah. Many of those green lasers are about 1mm at aperture. They also have poor divergence specs, so expanding it early may improve on that.

That size measurement sounds about right for a 5x expander.

Blord said:

Thanks

That would pose a problem. The dot is so wide that I can't measure at close distance. The dot is bigger than the sensor.
I will try again with a smaller focused dot on distance.

Click to expand...

Does that mean the expander is fixed focused ?
I know the beam exits out wide.
No changes able to make by user ?

Cheers, Sm.

Bionic-Badger said:

Yeah. Many of those green lasers are about 1mm at aperture. They also have poor divergence specs, so expanding it early may improve on that.

That size measurement sounds about right for a 5x expander.

Click to expand...

Jetlasers has also a smaller 3X BE. That would make a 3mm beam from a 1mm green. And with better divergence. But I don't have experience with that.

Smeerworst said:

Does that mean the expander is fixed focused ?
I know the beam exits out wide.
No changes able to make by user ?

Cheers, Sm.

Click to expand...

The expander is non-adjustable but the laser is still focusable with the BE mounted on it. I did a preliminary output test with the BE. The output without the BE is 750mW. With the BE it drops to ~600mW

How is yours losses with the BE ?

Blord said:

Jetlasers has also a smaller 3X BE. That would make a 3mm beam from a 1mm green. And with better divergence. But I don't have experience with that.



The expander is non-adjustable but the laser is still focusable with the BE mounted on it. I did a preliminary output test with the BE. The output without the BE is 750mW. With the BE it drops to ~600mW

How is yours losses with the BE ?

Click to expand...

Well i don't own the one you have..
But with the hercules i have and the x10 BE.. i also have a drop in power..Don't know what it was anymore.. but there is a drop.
was curious how this one turned out.

Blord said:

The expander is non-adjustable

Click to expand...

It might be adjustable. As I see in pictures there are several set screws, the big lens is in the knurled holder. Someone needed to make it a nice expander but a focusing lens.
Though it might be not wise to self adjust. The expander chamber can be filled with pure nitrogen, and your disturbance may brake seals. This might not apply to your model.

lazeristasUVISIR said:

It might be adjustable. As I see in pictures there are several set screws, the big lens is in the knurled holder. Someone needed to make it a nice expander but a focusing lens.
Though it might be not wise to self adjust. The expander chamber can be filled with pure nitrogen, and your disturbance may brake seals. This might not apply to your model.

Click to expand...

AFAIK few BEs are adjustable- however if the laser is focusable you do have some adjustment that you can do using the lases focus.

@ Blord-- can do it now buy when system allows you get a+3 for yet another excellant review and super pics!!! THANKS Kot

I have two 3X(plus 14500/16340& King Kong 26650s) in store here in Texas and you can also order at the new LPF members store on-line-

greenlaserpointer.org < there is a site with almost the same name -thats not us-its laser not lasers-

We are working on the store and soon will be adding many new items-

I personally want to thank all members for the support over the past two years - you all made this possible for me--TY very much.

GOT questions for Jetlasers??---please let my try to help before contacting Gray- help will come quicker and Gray can have more time to help us all in other ways------Len ;-):thanks::thanks::thanks:

@ BB- looking more like Monday to ship out the 3X -- hope it works for your idea- sounds like a good one!!