Pulsed laser noise analysis and pump-probe signal detection with a data acquisition card

A photodiode and data acquisition card whose sampling clock is synchronized to the repetition rate of a laser are used to measure the energy of each laser pulse. Simple analysis of the data yields the noise spectrum from very low frequencies up to half the repetition rate and quantifies the pulse en...

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Bibliographic Details
Main Authors: Werley, Christopher Alan, Teo, Stephanie Meng-Yan, Nelson, Keith Adam
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: American Institute of Physics 2013
Online Access:http://hdl.handle.net/1721.1/82531
https://orcid.org/0000-0001-7804-5418
https://orcid.org/0000-0002-6762-7313
Description
Summary:A photodiode and data acquisition card whose sampling clock is synchronized to the repetition rate of a laser are used to measure the energy of each laser pulse. Simple analysis of the data yields the noise spectrum from very low frequencies up to half the repetition rate and quantifies the pulse energy distribution. When two photodiodes for balanced detection are used in combination with an optical modulator, the technique is capable of detecting very weak pump-probe signals (ΔI/I 0 ∼ 10−5 at 1 kHz), with a sensitivity that is competitive with a lock-in amplifier. Detection with the data acquisition card is versatile and offers many advantages including full quantification of noise during each stage of signal processing, arbitrary digital filtering in silico after data collection is complete, direct readout of percent signal modulation, and easy adaptation for fast scanning of delay between pump and probe.