2D photoacoustic mapping system using a scanned focused spot to address a Fabry Perot polymer film ultrasound sensor.
Progress in Biomedical Optics and Imaging - Proceedings of SPIE
An ultrasound field mapping system has been developed for high resolution photoacoustic imaging applications. This operates by optically scanning a Fabry-Perot (FP) ultrasound sensor with a wavelength tuned, single focused spot of interrogating CW light at 850nm. By rapidly tuning the wavelength of the interrogating light source, the interferometer transfer function (ITF) can be obtained at each addressed point on the FP sensor. This enables the optimal bias wavelength point to be located prior to recording the photoacoustic signal. The FP sensors used have dichroic designs which allow the transmission of excitation laser pulses at 1064nm through the sensor into the underlying target. Such optical designs enable the photoacoustic sensor system to operate in backward mode. The area over which the photoacoustic signals can be mapped by the present system is 3.6cm × 2.5cm with an optically defined element size of 50μm. Images obtained (using a 12MHz bandwidth sensor) of phantoms consisting of India ink filled, 12μm bore tubes immersed in Intralipid, show lateral and depth resolutions of 110μm and 70μm, respectively at depths up to 7mm. It is considered that this system has the potential to be used for backward mode imaging of superficial structures such as the dermal and sub-dermal microvasculature.
|Title:||2D photoacoustic mapping system using a scanned focused spot to address a Fabry Perot polymer film ultrasound sensor|
|UCL classification:||UCL > School of BEAMS
UCL > School of BEAMS > Faculty of Engineering Science
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