Ultrafast pump-probe signal detection using a data acquisition card

Abstract

This work demonstrates the homebuilt, cost effective, pump probe signal detection using an advanced version of National Instrument data acquisition (NI-DAQ) card, which is used for multiple purposes in the same experiment. This advanced DAQ card is used as a controller for the linear stage, as an oscilloscope, and also for simultaneous acquisition of the signal from two photodiodes in synchronization with linear stage. The fast sampling rate of the DAQ card is used to quantify the peak power of the femtosecond laser pulse. This enables easier, faster, pulse to pulse data acquisition. A balanced detection technique is employed here, where the output from the two photodiodes are simultaneously sampled by the single DAQ card and is used to minimize pulse to pulse and slowly varying long-term fluctuations which are inherent to the laser source. We also review the significant developments in the DAQ card technology which helps to bypass the need for sophisticated instruments like lock-in amplifier or boxcar integrator, digital delay generator. This method is quite general and can be used in any experiment, where one needs to quantify the intensity variations in an experiment.

Anisotropic Nonradiative Recombination of Carriers in a Few-Layered MoS2 Probed by Mid-IR Ultrafast Spectroscopy

“…The detector output is coupled to the BOXCAR integrator (SR-280). The DC output from BOXCAR was collected by a data acquisition system (NI-BNC-2110) which is controlled by the LabVIEW programming . The detailed experimental layout is shown in Figure .…”

Filtering Noise in Time and Frequency Domain for Ultrafast Pump-Probe Performed Using Low Repetition Rate Lasers

“…In addition, the pulse to pulse energy fluctuation in case of 1 kHz systems are much more when compared to high repetition rate lasers. Thus, in case of low repetition rate lasers, signals are detected in time domain using boxcar or data acquisition cards with lot of averaging to achieve high S/N ratio [16][17][18][19][20]. Statistically, as the number of averaging (N) is increased, the standard deviation in the data can be reduced as √ N (for N >> 1).…”

“…For pump-probe measurements with high-repetition rate laser, they have replaced the boxcar with a lock-in-amplifier. Acquisition of large amount of data using data acquisition cards and post processing of the collected information with lot of averaging has also been used for improving signal to noise ratio [17][18][19][20]. Here, we present a new detection technique by utilizing the merits of both the boxcar and lock-in-amplifier instruments and the same is shown to be very useful in case of pump-probe experiments performed with a low repetition rate (1 kHz) laser system.…”

“…500 Hz are all higher harmonics of 50 Hz and 100 Hz the signal detected at these frequencies will have higher noise compare to that at 333 Hz. Several earlier reports used 500 Hz or various other chopping frequencies for the measurement of pump-probe signal with 1 kHz system [19,20,29].…”