Date of Award
Spring 2026
Document Type
Thesis
Terms of Use
© 2026 Aaron Dubois, Tanvir Islam, and Prashan Thapa Magar. This work is freely available courtesy of the author. It may be used under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license. For all other uses, please contact the copyright holder.
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Degree Name
Bachelor of Arts
Department
Engineering Department, Physics & Astronomy Department
First Advisor
Lynne Molter
Second Advisor
Patrick R. Banner
Abstract
Time-correlated photons can be used to demonstrate emerging technical applications such as ghost imaging, and they can demonstrate quantum-based phenomena in order to interest undergraduate students in engineering applications involving optics and quantum mechanics. In this work, we use spontaneous parametric down-conversion to generate time-correlated photons. To achieve this, we simulated laboratory parameters with MATLAB and designed optical and electrical setups. Specifically, we used a 405 nm diode laser, various common optical components, and a nonlinear crystal designed to generate time-correlated photons, and we used single-photon detectors, time-to-amplitude converters, custom flash-conversion analog-to-digital converters, a Teensy 4.1 microcontroller, and the Arduino IDE to detect the time-correlated photons. We present two significant results. First, we measured >100,000 counts per second 5 ± 1° on either side of our input laser which was within our theoretical expectations of 4–9° and much greater than our < 2000 dark counts per second. Our second major result was finding 15.8 ± 0.7 time-correlated counts per second with an SNR of 2.7. We also outline future extensions of our work including ghost imaging and generating polarization-entangled photons.
Recommended Citation
Dubois, Aaron , ‘26; Islam, Tanvir , ‘26; and Thapa Magar, Prashan , ‘26, "Time-Correlated Photons from Spontaneous Parametric Down-Conversion (SPDC)" (2026). Senior Theses, Projects, and Awards. 1091.
https://works.swarthmore.edu/theses/1091
