A Software-Based Lock-In Measurement for Student Laboratories

TL;DR

This paper presents a software-based lock-in measurement method for student labs, demonstrating how modulation and computational techniques significantly enhance sensitivity and data analysis skills.

Contribution

It introduces a novel software implementation of lock-in detection in student experiments, improving sensitivity and computational understanding.

Findings

Sensitivity increases by several orders of magnitude with modulation.

Students learn computational techniques for large data sets.

The method is accessible for educational purposes.

Abstract

A student laboratory experiment is presented that introduces the concept of a lock-in measurement through the exploration of the relationship between the power detected from a modulated light source and the distance between the source and the detector. The lock-in measurement is done in software using time streams for both the reference and the detector signals. The achievable experimental sensitivity is shown to increase several orders of magnitude over the simple case without using modulation. In addition, the student becomes familiar with computational techniques pertinent to large data sets.