How to generate very fast pulses (single puls)

[bjoern_lpt]

Hi,

I have a problem with generating fast pulses in LabView (2009 / 9.0, Win7-64enterprise).

I try to explain my project:

I have a femtosecond laser which sends pulses with a frequency of 200kHz. It mean 100fs puls 4.9999us low...100fs pulse.....

The laser have a gate which switches the laser output on and off (optic crystal --> very fast)

My task is to make it possible to send one single pulse out of the laser. You should have some user interface with LabView and enter

the amount of pulses (one, two... or more) and a big "fire" button.So we can make tests with a fixed amount of pulses.

I am very new to LabView and really dont know how to generate very short pulses. I try with a NI-USB6008 card and was possible to do some time loops

to generate something close to 100Hz. Now I have NI PCIx-6351 card. and want to try to generate pulses of 1us. How to do??? I dont see any posibility to go below 1ms.

Later on I want to try some syncronisation with the laser. I want to catch one pulse and sync to the next pulse.

Anyone able to help me with this task ?

btw: sorry for my clamsy english...

bjoern

[johnsold]

I doubt that any standard off the shelf DAQ device will be able to generate femtosecond pulses.  Most likely you will need to build a external circuit which can be triggered by a much longer pulse (ms or us) and which generates exactly one pulse in the femtosecond range for each leading edge of the trigger pulse.  The you can use the standard DAQ device to generate the trigger pulses.

Lynn

[bjoern_lpt]

Hi

I don't need to generate 100fs pulses. This is crazy to fast... I only need to generate a gate window that the pulse can pass.

Window have to be small. I would say something like 1us or 500ns. With some tollerance i only want to "select" one of the laser pulses.

bjoern

[johnsold]

bjoern,

OK.  A gate window should be something which can be accomplished.

The USB-6008 only uses software timing so fast pulses are not possible with that device.

I am not familiar with the PCIx-6351 and can find no reference to it on the NI website so I do not know what its capabilities are.  Many of the NI cards with digital I/O and counters can generate pulses or pulse trains in the timing range you want.  If you have the NI DAQ drivers, look for examples of pulse generation.

Lynn

[bjoern_lpt]

The card should be nice for that.

the specs you can find here: http://sine.ni.com/psp/app/doc/p/id/psp-892/lang/en

I only use one input (sync) and one output. So I think I can do very fast signals.

[bjoern_lpt]

Someone can help me ? Maybe some example vi ?

bjoern