pulsepal voltage output

cshl1

Hi everyone,

I am trying to use the PulsePal to trigger a monophasic 10hz laser pulse for optogenetic applications. When I test the laser output power independently (not connected to the PulsePal), I can obtain power readings as high as 30mW. However, when I incorporate the PulsePal, the laser output power appears to be capped at 0.50mW even with the pulse pal voltage parameter at the max 10V setting.

When I hook up the PulsePal to an oscilloscope and vary the voltage parameter, the output readings correctly reflect the voltage parameter value. I am using an MBLIII 473nm laser and would l like to be able to stimulate with a 10hz pulse with a voltage of around 5mW.

Thanks in advance for any insights as to why the voltage appears attenuated when using the pulse pal system!

Josh

Hi CSHL1,

Silly question - on the back face of the laser driver box, in the upper left corner, there's a switch to select 'TTL' or 'Analog' control. Is it set on 'Analog' mode?

Thanks,
-Josh

cshl1

Hi Josh,

Thank you so much for your reply, and so sorry for the delay in my response!

The laser driver box has been set to "TTL" control. As expected, there's an even more dramatic reduction in the output voltage when i switch it to "analog" control. However, switching the setting from TTL->Analog->TTL seems to have resolved the issue as now there doesn't seem to be a reduction in power output (on TTL control) when i trigger extended pulses (pulse duration 9 seconds, interpulse interval 1 second). Strangely there still does seem to be a significant reduction when I trigger with the "continuous on" function, as opposed to a spike train, but as i have no need for continuous illumination at the moment it won't be a problem. Thank you so much for your help!