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Full-Text Articles in Physical Sciences and Mathematics
Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody
Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody
Articles
The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …
Analog Holographic Wavefront Sensor For Defocus And Spherical Aberration Measurement Recorded In A Photopolymer, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy
Analog Holographic Wavefront Sensor For Defocus And Spherical Aberration Measurement Recorded In A Photopolymer, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy
Articles
An analog holographic wavefront sensor (AHWFS), for measurement of low and high order (defocus and spherical aberration) aberration modes has been developed as volume phase holograms in a photopolymer recording medium. This is the first time that high order aberrations such as spherical aberration can be sensed using a volume hologram in a photosensitive medium. Both defocus and spherical aberration were recorded in a multi-mode version of this AHWFS. Refractive elements were used to generate a maximum and minimum phase delay of each aberration which were multiplexed as a set of volume phase holograms in an acrylamide based-photopolymer layer. The …