Review: Jetlasers 3x and 5x beam expanders

I was fortunate to get these from Gray at Jetlasers.:bowdown:

:shhh:
I was able to atttach it to my Orion 5 mW pointer-its a little larger than common greenies. These were also reviewed with JETLASERS Ti 110mW 532 and Pl-C 250mW/532. I used blue glasses to make the photos better but the size of the spot seems much smaller thru the glasses. :tsk:

By moving the focus out on the PL-C the spot can be very large. Without any B.E. however it is nearly three time larger with focus extended but not as sharp.
The close pic are at about one meter and ths far ones about 6 meters.

three allen screw provided (two extras-no wrench came w/mine)

-be sure whn using with a PL-C that the shutter is completely open and that it stays open when attaching and thightening the adapter-

be sure that the adapter is on the laser fully and evenly.

Thighten each(3) screws in small increments and evenly but not too tightly-also be sure, to avoid scratching the laser that the screws are loosened enough when removeing the adapter.

When the allen screw heads are even with the outside of the adapter they will be also even with the inside of the adapter. When tightening(screwing in the adapter) hold tightly the adapter and the beam expander- not the lens of the PL-C as this will cause the shutter to close.


here is a link to a utube vid. made by JetlasersJet- this is a similar 100mW 532 Ti that I have used for this review.

YouTube - 3x Jetlasers beam expander and Titanium Green Laser Pointer pens


You will enjoy the foriegn version of 'Breakaway' --the first 1:50 is match burning followed by the addition of a JETL 3X beam expander.


If you de-focus the PL-C the spot enlarges while using the B. E.s


When using with pen lasers there is alot of 'play' so the set screws need to be turned in quite a way. For very thin pen lasers the adapter may not be suitable.

For the JETL Ti series the adapter is a snug fit- the set screws are almost not needed but use then to avoid accidents.

Here are some general pics of these very finely made optics. There are coated (blue).

Pics using Orion 5mW-and JETL 110(Ti) AND 250/532 PL-C

These and the last two in post #2 are all done with the 250 PL-C.

The huge spot is the Pl-C fully unfocused-w/o expander

Nice! I have been waiting for these to be available Have you done any lpm tests to see how much power is affected? How about some long distance night shots? Thanks for all your input and hard work for us!

^^^Thats the plan when I can spare the time. I was very disappointed with my pics and only posted what I did because I need to put something up asap. At small distance the spot is not much larger at 6 meters you can see a bigger change but less tha I expected. I will take some new pics at greater distances and do some metering as well (thanks for that suggestion Corbin, I had not thought of that.)

some may ask why not just de-focus the lens on the laser as opposed to using the BEs - one diff I noticed was, that the BEs make a much nicer and more uniform round spot and the image has none of the look that a defocused laser has. Just defocusing shows all the tiny imperfections in the lens(s) and the miniscule dust particles on the elements. Next photo session will show how a laser w/ BE works using a 20 inch mirror ball and at large distances and with fog/smoke.

Wait, I may misunderstand BEs, but arent they meant to expand the beam at the aperture so that it can focus at huge distances?... as opposed to using them to just defocus the beam into a large splotch?

Awesome. Cant wait to see those Long Night shots and LPM test.:beer:

+

FarewellToKings said:

Wait, I may misunderstand BEs, but arent they meant to expand the beam at the aperture so that it can focus at huge distances?... as opposed to using them to just defocus the beam into a large splotch?

Click to expand...

TBH until I got these I have never given BEs much thought and obviously much study either. Simply by the name expanders I always thought thier function was to 'expand the beam' -- so I must plead ignorance and I will defer to any of those here with much more accurate info on optics.

They are still attached to my laser so I will see if you are correct. bbl
hak

****************************************8

EDIT google search gave me this

http://www.beam-expander.com/pages/Beam-Expander-Theory.html

where they say this...

laser beam expander is designed to either decrease the laser's beam spot size at large distances or produce a larger collimated output laser beam. Laser beam expanders come in two main types: Keplerian laser beam expander or a Galilean laser beam expander. In its simplest form a Galilean beam expander consists of a postive and a negative focal length lens whereas the Keplerian consists of two postive focal length lenses. More advanced forms of laser beam expander utilise more than two lens elements to correct for spherical abberation. Both beam expander designs provide a certain anular magnifaction, called expander power. The beam diameter is first increased in size by this power and then the beam divergence is reduced by the same power. This combination yields a beam that is not only larger, but one that is highly collimated. The result is a smaller beam at large distances when compared to the laser alone. The laser beam expander is also useful when a larger collimated beam is required over a given range

Beam expanders are for increasing the diameter of the beam to get a proportionally lower divergence.

A 3x expander yields a third of the original divergence, assuming the expander is focused at infinity.

Hope that clears it up?

-Trevor

I am wondering where the sweet spot of a beam expander lies, meaning when you widen the beam a lot it must also lose intensity in the photos for long distances or will a say 100X BE just show a fine dot on the moon just kidding, but understand me right?!
Also 445nm diodes will it make the dot round?

I don't think the roundness of the beam profile has anything to do with the beam expanders used?

Anyhow, 10x beam expander are available now and promises a better but sure bulky design.
Pics to come:

UPDATED pics--my understanding Of BEs has gotten much better-
here arwe some pics of the 5X with a ProPL-D 635/200 and a green pointer. The last one shows the shape and size of my 635 (c-mount+square 'spot') at 8 feet with no BE.
my measurments...
At apeture-- ~1/8th inch or 3.175mm
at 88 inches~5/8th inch or 15.87mm

WITH the JL 5X BE ( & threaded adptor)
At apeture--~3/16th inch or 4.76mm
at 88 inches --~5/16 inch 0r 7.94 mm
so the BE redued the spot size at 88 inches to about 1/2 in size.
I will do some more measurements at greater distacnce soon.

How about a couple of beam shots showing actual larger collimated beam/beam expansion rather than just smaller dots at greater distances/dots showing better divergence?

Encap said:

How about a couple of beam shots showing actual larger collimated beam/beam expansion rather than just samaller dots at greater distances dots showing better divergence?

Click to expand...

I wanna say sure --will do asap- but ATM I m swamped with overdue projects-Two GBs- and getting ready for SELEM in ~2 weeks.

So far with this 5X all I have done is measure up close and at 88 inches.
I will do more when I can-sorry..hak

Nicely done reviews Len. I think the pics are fine also.
Next time you contact Gray, will you ask him to Email
me please ?
Thanks & Nice reviews............. rob

Good review, I like the pics. You took. They look fine on my crapy old monitor.