Characterizing a light dependent resistor (LDR) response to a laser diode using Malus' Law

Authors

  • Benjamin Jose C. Ambrosio ⋅ PH National Institute of Physics, University of the Philippines Diliman
  • Niña Zambale Simon ⋅ PH National Institute of Physics, University of the Philippines Diliman
  • Nathaniel P. Hermosa II ⋅ PH National Institute of Physics, University of the Philippines Diliman

Abstract

We propose a new technique to measure the non-linear response of a light dependent resistor (LDR) to a laser diode. We model the LDR resistance R versus the laser's intensity I as a power law model: R = aIβ. To determine β and $\alpha$, a parameter related to a, we configure the LDR and another variable resistor into a voltage divider circuit and obtain voltage measurements as we vary the light intensity via cross-polarizers. We obtain the best estimates for α = 13.271 and β = −0.924, confirming the non-linear response of the LDR. We compare these values to the calibration constants from the direct resistance measurement of the LDR, and discuss the advantages of our proposed technique.

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Article ID

SPP-2022-3D-05

Section

Physics Education

Published

2022-10-02

How to Cite

[1]
BJC Ambrosio, NZ Simon, and NP Hermosa, Characterizing a light dependent resistor (LDR) response to a laser diode using Malus’ Law, Proceedings of the Samahang Pisika ng Pilipinas 40, SPP-2022-3D-05 (2022). URL: https://proceedings.spp-online.org/article/view/SPP-2022-3D-05.