Development of a frequency-modulated photoacoustic microscope system for thermal imaging using a picosecond laser

Krishnan Sathiyamoorthy; Michael C. Kolios

doi:10.1117/12.2650401

16 March 2023 Development of a frequency-modulated photoacoustic microscope system for thermal imaging using a picosecond laser

Krishnan Sathiyamoorthy, Michael C. Kolios

Author Affiliations +

Proceedings Volume 12391, Label-free Biomedical Imaging and Sensing (LBIS) 2023; 123910J (2023) https://doi.org/10.1117/12.2650401
Event: SPIE BiOS, 2023, San Francisco, California, United States

Abstract

This work uses a picosecond pulsed laser in frequency-domain photoacoustic microscopy (FDPAM) for thermal imaging of the sample. It uses the principle of the frequency-domain photoacoustic (PA) spectroscopy employed for trace gas detection relying on the thermal effect caused by the absorbance of the sequence of picosecond pulses. The thermal effect is modulated to a periodic thermal wave using a mechanical optical chopper. The PA signal caused by the thermal wave is measured by a PA sensor containing a microphone connected to a lock-in amplifier. The FDPAM uses a high repetitive (100 kHz, 500 ps) picosecond pulsed laser, a kHz frequency microphone, a chopper, and a lock-in amplifier. The system is tested using a USAF resolution chart. The system imaged a chrome metal strip of thickness 120 nm and width 3.1 µm of a USAF chart. The system exhibits a PA signal with a maximum amplitude of 2x10^-4 V for a modulation frequency of 760 Hz. The signal is about four times lower than those obtained (8 x10^-4) by a 532 nm CW laser of power 3 mW. The SNR of the system for the USAF chart is 5.5 dB. The system has a lateral resolution of 3.1 µm. The imaging resolution of the system can be improved by using an objective with a lower f-number.

Conference Presentation

Citation Download Citation

Krishnan Sathiyamoorthy and Michael C. Kolios "Development of a frequency-modulated photoacoustic microscope system for thermal imaging using a picosecond laser", Proc. SPIE 12391, Label-free Biomedical Imaging and Sensing (LBIS) 2023, 123910J (16 March 2023); https://doi.org/10.1117/12.2650401

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