Time-correlated Raman and fluorescence lifetime spectroscopy at megahertz repetition rates

Heather McEwan; Gillian E. Brown; Andrea Usai; Ahmet T. Erdogan; Alistair Gorman; Colin J. Campbell; Robert K. Henderson; Neil Finlayson

doi:10.1117/12.2609660

2 March 2022 Time-correlated Raman and fluorescence lifetime spectroscopy at megahertz repetition rates

Heather McEwan, Gillian E. Brown, Andrea Usai, Ahmet T. Erdogan, Alistair Gorman, Colin J. Campbell, Robert K. Henderson, Neil Finlayson

Author Affiliations +

Proceedings Volume 11957, Biomedical Vibrational Spectroscopy 2022: Advances in Research and Industry; 119570C (2022) https://doi.org/10.1117/12.2609660
Event: SPIE BiOS, 2022, San Francisco, California, United States

Abstract

Raman spectroscopy is a hugely informative tool with a plethora of applications from biomedicine to analytical chemistry. Potentially, the technique could improve liver transplantation success rates through investigating Raman signals associated with metabolic changes prior to transplant rejection. However, studying biological systems is challenging since background fluorescence dominates the weak Raman signal. Thus, there is a need to improve signal-to-noise and Raman-tofluorescence ratios and drive down spectral acquisition times. Pulsed lasers combined with time-resolving single photon avalanche diode (SPAD) detection systems have been shown to enhance Raman and fluorescence discrimination. We report significant advances in time-correlated single photon counting (TCSPC) Raman spectroscopy using a laser exhibiting up to 200 W peak power and 40 MHz repetition rates in combination with a 512 spectral channel, 16.5 gigaevent/s throughput SPAD histogramming line sensor. Using a diamond sample, we report 0.4 MHz Raman count rates, millisecond spectral acquisition times, and signal-to-noise ratios of over 200. We demonstrate simultaneous, singleexposure acquisition of Raman and fluorescence signals in sesame oil. Time-based Raman-fluorescence discrimination techniques are subject to fluorescence signal tail influences from previous pulses, and data obtained with laser periods of 25 ns and 50 ns are presented. We achieved optimised Raman-to-fluorescence ratios through adjustment of histogram bin positions in 63 ps increments. Achieving high count rates while discriminating fluorescence from Raman signals unlocks the potential of combined Raman/fluorescence lifetime spectroscopy for biomedical imaging applications.

Citation Download Citation

Heather McEwan, Gillian E. Brown, Andrea Usai, Ahmet T. Erdogan, Alistair Gorman, Colin J. Campbell, Robert K. Henderson, and Neil Finlayson "Time-correlated Raman and fluorescence lifetime spectroscopy at megahertz repetition rates", Proc. SPIE 11957, Biomedical Vibrational Spectroscopy 2022: Advances in Research and Industry, 119570C (2 March 2022); https://doi.org/10.1117/12.2609660

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
9 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Raman spectroscopy

Signal to noise ratio

Sensors

Spectroscopy

Diamond

Pulsed laser operation

Spectrometer engineering

Show All Keywords

Keywords/Phrases

Search In:

Publication Years