Dr. Deano M. Farinella Profile

Dr. Deano M. Farinella

at Univ of Minnesota

SPIE Involvement:

Author

Publications (2)

SPIE Journal Paper | 5 June 2024 Open Access

Two-dimensional electro-optical multiphoton microscopy

Deano Farinella, Samuel Stanek, Harishankar Jayakumar, Zachary Newman, Jacob Gable, James Leger, Aaron Kerlin

NPh, Vol. 11, Issue 02, 025005, (June 2024) https://doi.org/10.1117/12.10.1117/1.NPh.11.2.025005

KEYWORDS: In vivo imaging, Relays, Crystals, Microscopes, Electrooptics, Ultrafast phenomena, Multiphoton microscopy, Ultrafast imaging, Laser crystals, Neurophotonics

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 6 March 2021 Open Access

Improving laser standards for three-photon microscopy

Deano Farinella, Arani Roy, Chao Liu, Prakash Kara

NPh, Vol. 8, Issue 01, 015009, (March 2021) https://doi.org/10.1117/12.10.1117/1.NPh.8.1.015009

KEYWORDS: Pulsed laser operation, Microscopy, Distortion, Photodiodes, Second-harmonic generation, Microscopes, Photons, Laser sources, Phase measurement, Laser stabilization

Read Abstract +

Significance: Three-photon excitation microscopy has double-to-triple the penetration depth in biological tissue over two-photon imaging and thus has the potential to revolutionize the visualization of biological processes in vivo. However, unlike the plug-and-play operation and performance of lasers used in two-photon imaging, three-photon microscopy presents new technological challenges that require a closer look at the fidelity of laser pulses. Aim: We implemented state-of-the-art pulse measurements and developed innovative techniques for examining the performance of lasers used in three-photon microscopy. We then demonstrated how these techniques can be used to provide precise measurements of pulse shape, pulse energy, and pulse-to-pulse intensity variability, all of which ultimately impact imaging. Approach: We built inexpensive tools, e.g., a second harmonic generation frequency-resolved optical gating (SHG-FROG) device and a deep-memory diode imaging (DMDI) apparatus to examine laser pulse fidelity. Results: First, SHG-FROG revealed very large third-order dispersion (TOD). This extent of phase distortion prevents the efficient temporal compression of laser pulses to their theoretical limit. Furthermore, TOD cannot be quantified when using a conventional method of obtaining the laser pulse duration, e.g., when using an autocorrelator. Finally, DMDI showed the effectiveness of detecting pulse-to-pulse intensity fluctuations on timescales relevant to three-photon imaging, which were otherwise not captured using conventional instruments and statistics. Conclusions: The distortion of individual laser pulses caused by TOD poses significant challenges to three-photon imaging by preventing effective compression of laser pulses and decreasing the efficiency of nonlinear excitation. Moreover, an acceptably low pulse-to-pulse amplitude variability should not be assumed. Particularly for low repetition rate laser sources used in three-photon microscopy, pulse-to-pulse variability also degrades image quality. If three-photon imaging is to become mainstream, our diagnostics may be used by laser manufacturers to improve system design and by end-users to validate the performance of their current and future imaging systems.

DOWNLOAD PAPER

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years