337 nm pulsed Nitrogen laser energy output

[Olwood]

I'm struggling to get an energy reading from a pyro electric laser energy meter measuring one of my pulsed nitrogen lasers. On another similar similar laser readings are fine, so I assume the meter is working fine. These are research grade lasers meant for ionisation. Both lasers produce visible fluorescence from white card placed in the beam line. The beams are attenuated to prevent damage to the meter.

Could this be a sign of needing to change the plasma cell on the problematic laser? I'm reluctant to test the beam unattenuated as I don't want to damage the meter.

Thanks.

 

[Sigurthr]

You're using a thermal LPM, right? (Pyroelectric implies such, unless it is an obscure brand name). N2 lasers are short pulse width emissions, and generally limited in repetition rate unless it's a flowing gas system. It's likely you've over-attenuated the beam or the pulse width is too short to register a thermal change large enough on the sensor.

 

[ultimatekaiser]

You're using a thermal LPM, right? (Pyroelectric implies such, unless it is an obscure brand name). N2 lasers are short pulse width emissions, and generally limited in repetition rate unless it's a flowing gas system. It's likely you've over-attenuated the beam or the pulse width is too short to register a thermal change large enough on the sensor.

this is probably exactly it. only certain meters can read short pulses like that (mine can, up to a few joules :tinfoil and only between certain power ranges.

 

[Cyparagon]

specs of the energy meter and both lasers would be helpful to know.

 

[Olwood]

Thank you for the replies. The meter is a thermal LPM, yes. I will add the specs later today.

The laser specs are:
- up to 400 uJ per pulse
- 0 - 20 Hz
- 4 ns pulse width


Meter specs

Molectron J9LP 8096
519 V/J @1064 nm

This does work with a similar pulsed laser so I suspect over attenuation is to blame.

 

[Cyparagon]

Google says the Molectron J9LP is rated for 2uJ to 20mJ, so the meter will be safe, and will even perform better with no attenuation.

 

[Olwood]

Google says the Molectron J9LP is rated for 2uJ to 20mJ, so the meter will be safe, and will even perform better with no attenuation.

Thank you for this. I will perform assessment with no attenuation next week.