Low divergence FAC corrected Red combiner modules

[logsquared]

Hey everyone. Havn't posted in some time. I was going through my shop and have some prototype laser combiners that may be of interest. These are low divergence lasers that use the P73 fac corrected diodes. The diodes are special made by lasertree and not the ones they have on ebay.

The first is a 3 red combiner that has two extra ports for a green and a blue fac corrected diode. The Blue and Green are not installed and also would need appropriate dicros to make a full RGB. I will include the extra circuit board diode mountd and hardware if you want to experiment making it RGB. The output lens is a high quality coated achromat. divergence is about .35mRad.
RGB

The next is a 1" round 2 diode red combiner with a PBS cube to combine the beams. This has ridiculously low divergence for a MM red, about .2 mRad!
PBS SOLD

The third is a knife edge 3 diode red combiner. It has about .35 mRad divergence. The body diameter is 1". I have 3 of these available. This module has a lid that covers the mirrors.
3X

All modules are anodized black and have 24 pitch focus threads. These are just the optics and diodes. user will have to provide drivers batter holder etc.
photos

Please post any questions here. Also, more photos to come.

 

[farbe2]

Do you have some values of beam diameter at output and at far field?
Maybe even pictures?

I expect to see one axis worse (divergence or diameter at output) than the other axis.

How high is the loss of the optics (fibre / collimating lens) combined?
Thats just to see how much output can we expect. Do you have data at say 650mA (typ operating current)?

-farbe

 

[liveforphysics]

I'm extremely interested in your optics to generate that low divergence.

Can you share info to buy the FAC corrected red laser diodes?

 

[logsquared]

There should be more photos with spot and aperture on the photo link now. The spots on the cinder block are at 130 feet.

The loss from the fac is negligible. Im at work now, can get some measurements tomorrow. Hopefully can get some outside beam shots tonight.

 

[kecked]

If it’s anything like what I’ve got in the past his stuff is amazing. Pm me pricing

 

[logsquared]

I'm extremely interested in your optics to generate that low divergence.

Can you share info to buy the FAC corrected red laser diodes?

The FACed diodes are from laser tree. The laser tree "linear" is too narrow and the "square" is too big in the fast axis for this type of set-up. I had them special made. I think minimum order was 20 pcs and they were about double the normal price. I have a few unused diodes if you're interested.

The collimator is a spherical 100mm PCX lens or 100mm achromat in the RGB set-up.

As far as the knife edging goes, the modules are machined so the diodes are the same distance from the main lens. In the RGB unit the diodes all "fire" towards two center points along the center of the main beam. Then the mirrors are positioned to "knife" the beams and glued with uv epoxy.

The 3X with the diodes on the back of the barrel "fire" into a cross and the side mirrors pick them up and aim them to the main lens. This method proved to be very easy to align compared to the RGB. I was able to do it completly by hand and then hit the glue with uv and done. The RGB took more finesse, I used a XY positioner to set those.

The PBS unit is just two diodes rotated 90deg and fire through the cube at the rear of the module. You can see a small squarish hole near the rear that the cube was inserted into. This PBS unit has the tightest beam for two reasons: 1 the beams are overlaped, 2 the diodes are in exactly the same focal plane. That is why the divergence is slighly better. The 3X could be made to have the same far field as the PBS. It would just take a small shim between the diode and the body. Becuase i could still get a good focus on all three beams I didn't add any shims. Could be a future experiment for someone.

All the modules are adjustable for F.F. beam overlap. Its very simple. Just loosen the screws that hold the diode you need to position and tap the diode with a small screw driver. Perfect overlap can be done by hand.

Do you have some values of beam diameter at output and at far field?
Maybe even pictures?

I expect to see one axis worse (divergence or diameter at output) than the other axis.

How high is the loss of the optics (fibre / collimating lens) combined?
Thats just to see how much output can we expect. Do you have data at say 650mA (typ operating current)?

-farbe

the output per diode is around 3x10mm roughly. Check the pics, its in there somewhere.

The divergence is pretty close in both directions. This is becuase the custom FAC is designed to do this with a 100mm Fl lens.

The raw FACed diode is only a few percect lower than an unFACed diode as best as i can tell. I measured a few P73 I had from a while back and the FACs are within a few percent.

Here are some numbers I measured today. raw unFACed at 650mA = 500mW and 900mA= 736mW

Note: Measuring the modules, I had a bit of trouble getting the beam to fit on my laser head sensor. Possibly a bit of clipping.

The RGB 5 port unit (Actually come to think of it it should be possible to make a 5 P73 combiner with this instead of RGB)
650mA = 1W 900mA = 1.4W

PBS unit
650mA = 870mW 900mA = 1120mW

3X
650mA = 1.1W 900mA = 1.45W

If it’s anything like what I’ve got in the past his stuff is amazing. Pm me pricing

Thanks!


These modules were prototype experiments for another project. The diodes only have about an hour or so from set-up and alignment. They are sold as a project and not intended to be any type of commercial product.

I would just like to get what I have into them. $175 for the RGB, $175 for the 3X's and $150 for the two diode PBS unit.

Was too tired last night to get any beam shots. Will try again tonight.



First two are the RGB, second two the PBS. Looks pretty awesome for red i think. even with the street lights every 2 feet.

 

[aaronnoraa]

Off topic but can I ask who makes those SR speakers in the warehouse photo? Those look like some seriously nice loudspeakers.

 

[logsquared]

Off topic but can I ask who makes those SR speakers in the warehouse photo? Those look like some seriously nice loudspeakers.

Electro-voice Xi-2183. 2x 18", 12" , 2". Serious beasts.