Development of compact multimodal two-photon and three-photon microscopy
department or school: Applied Science, Faculty of
department or school: Electrical and Computer Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Wu, Wentao
issued: 2024-08-21T18:24:02Z
issued: 2024
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Multiphoton microscopy (MPM) is an optical microscopy technique visualizing tissues non-invasively in high resolution. MPM utilizes femtosecond laser pulses for multiphoton excitation. MPM provides tissue-specific contrasts that are useful in clinical applications. Two-photon excitation fluorescence (2PEF) visualizes cells; second harmonic generation (SHG) visualizes collagen fibers; third harmonic generation (THG) visualizes lipids. While being utilized in research for decades, clinical applications are still limited. The bulkiness and complexity of free-space lasers, microscope platforms, and scanners prevent convenient clinical use. Different from ex-vivo imaging where labeling can enhance signals, clinical imaging relies on label-free signals which can be significantly weaker. Multimodal MPM with multiple contrasts from two- and three-photon excitations helps clinical imaging enhance biochemical specificity and provide complementary information. Depth-scanning further provides volumetric information about tissue. A handheld MPM imaging head with multimodal and depth-scanning capabilities is needed to carry the technique to clinical applications. This dissertation explores the potential of developing compact depth-scanning multimodal MPM with simultaneous two- and three-photon imaging. Harmonic generation is theoretically analyzed under focused Gaussian beam. The impact of phase-matching is discussed to show interface-sensitivity of SHG and THG. A 1580-nm Er-doped femtosecond fiber laser serves as a compact source for excitation, and part of the laser is converted to 790 nm to achieve dual-wavelength two- and three-photon excitation. Signals of 2PEF, SHG, and THG are separated and then detected by photomultiplier tubes. A signal subtraction method is proposed to address crosstalk. To further improve the compactness, a miniaturized depth-scanning objective (numerical aperture ~0.53) consisting of an aspheric and a plano-convex lens is fabricated. A shape-memory-al…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/88990
note: Development of Compact Multimodal Two-Photon and Three-Photon Microscopy by Wentao Wu B.Sc. in Electronic Science and Technology, Harbin Institute of Technology, 2015 Ph.D. in Physical Electronics, Harbin Institute of Technology, 2020 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (ELECTRICAL AND COMPUTER ENGINEERING) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2024 © Wentao Wu, 2024 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Development of Compact Multimodal Two-Photon and Three-Photon Microscopy submitted by Wentao Wu in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Electrical and Computer Engineering Examining Committee: Shuo Tang, Professor, Electrical and Computer Engineering, UBC Supervisor Haishan Zeng, Professor, Dermatology and Skin Science, UBC Supervisory Committee Member Calum MacAulay, Clinical Associate Professor, Pathology and Laboratory Medicine, UBC University Examiner Boris Stoeber, Professor, Electrical and Computer Engineering, UBC University Examiner Jianan Qu, Professor, Electronic and Computer Engineering, Hong Kong University of Science and Technology External Examiner Additional Supervisory Committee Members: Robert Rohling, Professor, Electrical and Computer Engineering, UBC Supervisory Committee Member iii Abstract Multiphoton microscopy (MPM) is an optical microscopy technique visualizing tissues non-invasively in high resolution. MPM utilizes femtosecond laser pulses for multiphoton excitation. MPM provides tissue-specific contrasts that are useful in clinical applications. Two-photon excitation fluorescence (2PEF) visualizes cells; second harmonic generation (SHG) visualizes collagen fibers; third harmonic generation (THG) visualizes lipids. While being utilized in r…
has type: Thesis/Dissertation
date issued: 2024-11
is shown at: 10.14288/1.0445119
language: eng
degree discipline: Electrical and Computer Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Tang, Shuo
type: Text
identifier URI: http://hdl.handle.net/2429/88990