Laserwave 25mm dichros

[Doc]

I did some tests tonight.

I measured a (modulated) 670mW of 650 red from my scanners. Then I removed the reflect blue dichro (25mm Laserwave) and the red power shot up to a measured 800mW.

I then re installed the dichro and tried different angles:

45° = 670mW
60° = 685mW
70° = 705mW
80° = 760mW
88° = 790mW

I didn't fancy trying 90° for fear of killing my lasers, but a fairly conclusive test. I did try rotating the dichro through 360° in approx 45° increments, but it made no difference.

This; combined with my massive cube losses and galvo mirror overspill mean that my measured 1.8W (at 5v unmodulated) of red ends up as 900mW

[buffo]

Might be worth spending ~$100 on a set of dichros from Edmund's, just to see how they stack up. For sure I'm not losing anywhere near those power levels with mine.

Adam

[Doc]

Might be worth spending ~$100 on a set of dichros from Edmund's, just to see how they stack up. For sure I'm not losing anywhere near those power levels with mine.

Adam

Edmund reflect blue ordered

[buffo]

Cool! Let us know how it works out for you.

I've had mine for 2.5 years now, and I've been quite pleased with them.

Adam

[mccarrot]

Hi doc thanks for testing, it backups my measurements off the dichro.

I will be ordering some dichro's from KVANT and another supplier and let you know my results.

About the PBS I have talked to one of the PBS suppliers and they say a loss off 2% is possible with there PBS. With the laserwave PBS I no have a loss of about 13%.

I will order a PBS also for my new red build and let you know.

[Doc]

Hi doc thanks for testing, it backups my measurements off the dichro.

I will be ordering some dichro's from KVANT and another supplier and let you know my results.

About the PBS I have talked to one of the PBS suppliers and they say a loss off 2% is possible with there PBS. With the laserwave PBS I no have a loss of about 13%.

I will order a PBS also for my new red build and let you know.

Cool, thanks. My reds (Laserwave 800mW) measure 900mW each (@ 5v mod), one of which was custom made by Bridge for vertical polarisation.

After the cube I'm measuring 620mW ish from each laser. If I turn the cube I can increase the transmit value up to 750mW ish, but I lose a corresponding amount from the reflect V laser so no gains. I'm wondering whether the lasers have a lot of random polarisation in the output? If so; could a wave plate help?

I guess I should have just bought a single 1Watt 635.

[Mr.Coffee]

somebody on here built a small diode rig and used knife edge mirrors instead of a pbs cube, I believe part of the reasoning was to minimize losses. You could always give it a shot and see what happens.

[Doc]

somebody on here built a small diode rig and used knife edge mirrors instead of a pbs cube, I believe part of the reasoning was to minimize losses. You could always give it a shot and see what happens.

I use the knife mirror trick to combine my blues, but the reds have beams like sausages and already overspill the galvos, so that's not an option (unless anybody has any spare first surface table tennis bats?

[sbk]

After the cube I'm measuring 620mW ish from each laser. If I turn the cube I can increase the transmit value up to 750mW ish, but I lose a corresponding amount from the reflect V laser so no gains. I'm wondering whether the lasers have a lot of random polarisation in the output? If so; could a wave plate help?

I guess I should have just bought a single 1Watt 635.

I had good luck with a PBS from Lasever, with only a few % losses on my old 660nm dual MAXyz. You should try one, they are relatively cheap...

They sell dichro too, with >95% transmission anounced, but I've not tested them.

[Doc]

My Edmund Dichro arrived today (less than 24 hours!)



Here's the before shot:






Here's the new beasty sat next to the Laserwave item.

Because the Edmund is so thick I had to realign the lasers due to beam offset effect.







... and here's the after shot:







FYI there was a 3mW loss of green through this Edmund!




Here's a shot with the galvos out of the loop







Now if I could just get my other stolen half Watt back from that pesky PBS cube..........




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