Fac/ sac lens attachment to 40watt diode laser

[ducatidragon916]

So I have had this laser unit CS- mount 975nm 600 um emitter. I was able to find a fac/sac lens combo to try my hand at fixturing this lens on the die. Standard package for the die is CS-975-040W-65. I was somewhat successful at attaching the lens with a jig setup as I will show at the end. I decided to add a TEC unit to help keep things cool. Now what is perplexing me is when I fire the laser up and observe with an ir image sensor, I notice the beam looking horizontal with intense lines in the center and degrading Intensities of lines on the left and on the right side of the beam. I am thinking I need an aspheric lens to set things straight etc so to speak.

 

[ducatidragon916]

So I have had this laser unit CS- mount 975nm 600 um emitter. I was able to find a fac/sac lens combo to try my hand at fixturing this lens on the die. Standard package for the die is CS-975-040W-65. I was somewhat successful at attaching the lens with a jig setup as I will show at the end. I decided to add a TEC unit to help keep things cool. Now what is perplexing me is when I fire the laser up and observe with an it image sensor I notice the beam looking horizontal with intense lines in the center and degrading I traitors of lines on the left and on the right side of the beam. I am thinking I need an aspheric lens to set things straight etc so to speak. Forgive me as the second image is a blowout in intensity as it is about 50mm away from the lens.

Here is another image showing the sensor with the lines

 

[ducatidragon916]

Here is another image showing the sensor with the lines

These are the images of the setup of the attachment of the fac/sac lens. The jig was made from microscope parts to car parts and a printer I took apart for the stamped metal pieces that could fit and hold the lens while I tested it.

 

[ducatidragon916]

These are closeups of the fac/sac lens being attached to the die. I used hysol c epoxy which is temperature stable and relatively clean and doesn’t out gas as other epoxies.

 

[ducatidragon916]

Here is some images of the setup of the TEC and its parts to attach the die to the cooling structure. I may in the near future add another layer of TEC as I don’t think it is cooling enough to keep it cool for longer periods of experimenting.

 

[ducatidragon916]

Would using a Plastic aspheric lens be affected by the IR energy passing through it? Would it melt? I am waiting on the arrival of the rectangular Aspheric lens to see if 1. Improves the beam profile and 2. Can it handle the power? We will have to wait and see when I receive it and will post the results and images obtained by using it.