A Caltech Library Service

Exploring How Entangled Photon Correlations Can Enhance Spectroscopy


Hickam, Bryce Patrick (2024) Exploring How Entangled Photon Correlations Can Enhance Spectroscopy. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ez5h-qp07.


Quantum light sources consisting of highly correlated or "entangled" photon pairs are increasingly becoming popular alternatives to classical light sources to perform microscopy and spectroscopy. Entangled photon pairs can replicate and enhance spectroscopic signals and have practical advantages compared to the pulsed laser systems that are typically utilized to perform these measurements. For instance, entangled photons are inherently low-flux, enabling measurements to be performed without undesired photoeffects, such as sample heating and degredation or nonideal photoinduced sample behavior. In addition, entangled photon sources can be generated and manipulated on much smaller physical footprints than state-of-the-art pulsed laser systems with comparable frequency bandwidths and time resolutions. Together, these capabilities could allow for the development of spectroscopic instruments that do not rely on bulky, expensive pulsed laser systems that necessitate teams of specialists to maintain. In turn, this instrument development could enable more widespread access to exotic forms of atomic and material characterization.

Despite a growing body of theoretical work, the field of experimental entangled photon spectroscopy is still nascent and entangled light-matter interactions have yet to be fully characterized in laboratory settings. Here, we investigate entangled photon light-matter interactions towards the goal of developing entangled spectroscopic techniques. A broadband entangled photon source with femtosecond coherence times is designed and characterized to perform these measurements. Using this source and an entangled photon spectrometer, characterization of the entangled photon enhancement to two-photon absorption are attempted by in studies of two different molecular dyes, Rhodamine 6G and zinc tetraphenylporphyrin. The entangled photon two-photon absorption enhancement is determined to be below previously reported values due to the presence of single photon scattering signals. Finally, entangled photons are utilized to replicate fluorescence lifetime measurements using a continuous wave pump laser and the temporal correlations inherent to entangled photon pairs. As the first experimental demonstration of this technique, the fluorescence lifetimes of indocyanine green in three solvent systems are measured.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:physical chemistry, spectroscopy, entangled photons, quantum, entangled two-photon absorption, molecular excited state lifetime measurement, interferometry
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Cushing, Scott K.
Thesis Committee:
  • Hadt, Ryan G. (chair)
  • See, Kimberly
  • Blake, Geoffrey A.
  • Cushing, Scott K.
Defense Date:25 August 2023
Funding AgencyGrant Number
NSF Graduate Research Fellowship1745301
Record Number:CaltechTHESIS:08032023-213853772
Persistent URL:
Related URLs:
URLURL TypeDescription adapted for Chapter 2 adapted for Chapter 3 adapted for Chapter 4 adapted for Chapter 5
Hickam, Bryce Patrick0000-0003-2120-4769
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:16151
Deposited By: Bryce Hickam
Deposited On:20 Sep 2023 19:32
Last Modified:08 Nov 2023 00:19

Thesis Files

[img] PDF - Final Version
See Usage Policy.


Repository Staff Only: item control page