Nd:YAG laser optical system setup

[HAYAO]

Is there anyone who has experience in setting up optical system for exciting a sample using Q-switch mode of Nd:YAG laser? I am currently looking at the optical system which I did not setup (someone else did, but the person is absent and cannot contact).

I have no background whatsoever in optical system setups, and I have a problem that the laser is emitting red light for some reason. I am currently trying to use THG of 1064 nm emission from Nd:YAG (355 nm). However, I do not know the diagnostics of this optical system when it's not working right.

What can be wrong? Could it be the non-linear optical crystal?

 

[boneh3ad]

I know most Nd:YAG lasers operate at 1064 nm, but there are other wavelengths that exist as well. Is it possible that your laser is actually operating at, for example 1320 nm and you are seeing its second harmonic (660 nm), which would be red and visible?

 

[HAYAO]

sorry, i forgot to mention that the laser is emitting green pulse laser, but also at the same time, in much much lower intensity, red light with large cross section.

 

[blue_leaf77]

How is the laser pumped? Are you sure the red light is not coming from the pump laser, which is usually indeed red diode laser?

 

[HAYAO]

The laser is pumped by a flashlamp. The pump color is white.

Most likely xenon flashlamp