- #1
shamrock08
- 4
- 3
I am working with a Nd:YAG pulsed laser system produced by Continuum back in the early 2000s called the Precision II 8000. We just received the laser from another department at the University and have been setting it up to work unseeded at 532nm.
The previous lab team had adjusted the output coupler (OC) which is usually a big no but with the help of a very patient tech, we were able to get the OC realigned(ish) and then went on to realign the oscillator. We began routing the beam out of the cavity into a test area for ensuring beam quality.
We quickly realized that the beam was contracting significantly despite using 532nm laserline mirrors and the optical path only being a little more than 11'. The beam's contraction was noted using burns as reference. To better explain the contraction, the major axis reduced from 7mm to 6mm and the minor axis reduced from 7mm to 5mm.
Along with contracting, burns taken show that the beam quality is slightly elliptical and jagged around the edges, which is a far cry from the ideal circular shape we would want. As for what I've done so far: adjusted the telescoping optics prior to the amplifier, adjusted the rear mirror in the oscillator, aligned the amplifier and SHG crystal for proper power output, checked all optics for clipping and damage, changed the polarization of the beam using a waveplate and polarizer, and pleaded with the laser gods for guidance. I have not replaced the YAG rods yet.
If you have any questions, I will answer to the best of my ability, and any suggestions, I will take into consideration. Thanks for any assistance you can provide!
The previous lab team had adjusted the output coupler (OC) which is usually a big no but with the help of a very patient tech, we were able to get the OC realigned(ish) and then went on to realign the oscillator. We began routing the beam out of the cavity into a test area for ensuring beam quality.
We quickly realized that the beam was contracting significantly despite using 532nm laserline mirrors and the optical path only being a little more than 11'. The beam's contraction was noted using burns as reference. To better explain the contraction, the major axis reduced from 7mm to 6mm and the minor axis reduced from 7mm to 5mm.
Along with contracting, burns taken show that the beam quality is slightly elliptical and jagged around the edges, which is a far cry from the ideal circular shape we would want. As for what I've done so far: adjusted the telescoping optics prior to the amplifier, adjusted the rear mirror in the oscillator, aligned the amplifier and SHG crystal for proper power output, checked all optics for clipping and damage, changed the polarization of the beam using a waveplate and polarizer, and pleaded with the laser gods for guidance. I have not replaced the YAG rods yet.
If you have any questions, I will answer to the best of my ability, and any suggestions, I will take into consideration. Thanks for any assistance you can provide!