First Advisor

Erik Sánchez

Date of Award

Spring 6-2024

Document Type


Degree Name

Bachelor of Science (B.S.) in Physics and University Honors






2-photon, fluorescence, far-field, nonlinear optics, bioimaging


The objective of this project was to convert a Sarastro 2000 confocal laser scanning microscope (CLSM) into a system capable of far-field two-photon excitation (TPE) imaging for the use of the PSU Biology department. TPE microscopy operates on the ability of fluorophores to accept two photons each with half the energy of a desired transition in a single quantum event via a virtual energy state and then emit a higher energy photon upon relaxation. This is preferable to single-photon excitation (SPE) imaging due to lower photon imaging, causing less damage to delicate biological samples, as well as the inherent localization due to the low excitation volume. The adaptation process included physically altering the CLSM by replacing the onboard argon laser with a Ti:sapphire laser, replacing optical components for compatibility with the new laser, and implementing a new scan mechanism. The new scan mechanism, a custom analog two-mirror galvanometer head, interfaces with an analog data acquisition board and software designed for analog motor control and data analysis. Components were successfully replaced, and future work includes software compatibility and laser alignment and enclosure.

Included in

Optics Commons