I am using photoelastic modulator (PEM) which generates 50 KHz pulses which were down modulated to 10 Hz pulses for circular dichroism (CD) purpose in gas phase. In CD, left circular polarized (LCP) and right circular polarized (RCP) light have to be taken into consideration. Since CD=LCP-RCP. I am trying to develop a program called R2PICD. I am too new to write any Labview program. Here, I am briefly providing information what I want to do so somebody can help me.
10 Hz pulse after down modulation is used to trigger the delay generator which is further dived into two 5 Hz pulses (output channels A and B). After providing certain delay of few microsecond (e.g. 5 µs in channel A and 15 µs in channel B of delay generator), these two 5 Hz pulses were recombined into channel C, which is called modified 10 Hz pulse. This practice has been done to get alternate LCP and RCP pulses.
This modified 10 Hz pulse is used for triggering the pulsed ns laser. This laser beam will interact with molecules in gas phase after passing through polarizers and PEM to generate circular polarized light. Let’s assume that, laser scans from wavelength 500 nm to 501 nm with step width 0.01 nm. The number of steps will be 100. At 500 nm, if 32 pulses coming from laser is considered then 16 pulses will be of LCP and 16 pulses will be RCP in LCP-RCP-LCP-RCP----manner. Then it is required to take all RCP in one domain and all LCP will be in another domain. Next, CD = ΣLCP – ΣLCP at 500 nm. Then wait for some time to move the grating by 0.01 nm. Repeat the same procedure for 500.01 nm and wait again to move grating and so on. Here after interaction with molecule, it will generate amplitude for each pulse. Amplitude should get for alternative pulses.
In brief, I am interested in 1) separating alternative pulses of modified 10 Hz pulse in two separate domain as LCP and RCP precisely. 2) I want to have amplitude value after interaction of laser beam with molecule.