Prof. Peter D. Townsend Profile

Prof. Peter D. Townsend

at Univ of Sussex

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Author

Publications (5)

Proceedings Article | 18 January 2011 Paper

Will anyone remember us? Thoughts on information loss caused by progress

Peter Townsend

Proceedings Volume 7747, 77470X (2011) https://doi.org/10.1117/12.881017

KEYWORDS: Data storage, Photography, Tablets, Transistors, Charge-coupled devices, Manufacturing, Optical fibers, Compact discs, Video, Climate change

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Proceedings Article | 18 January 2011 Paper

Low cost enhancements of photomultiplier sensitivity

S. Harmer, Peter Townsend

Proceedings Volume 7747, 77470A (2011) https://doi.org/10.1117/12.881090

KEYWORDS: Absorption, Photomultipliers, Quantum efficiency, Reflectivity, Reflectors, Modeling, Polarization, Sensors, Reflection, Dielectric polarization

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Proceedings Article | 22 April 2005 Paper

Tumor detection by exogenous fluorescent dyes using new generation photo-multiplier tubes

Ekaterina Borisova, I. Angelov, Vanya Mantareva, D. Petrova, Peter Townsend, L. Valberg, Lachezar Avramov

Proceedings Volume 5830, (2005) https://doi.org/10.1117/12.618833

KEYWORDS: Luminescence, Tissues, Signal detection, Sensors, Melanoma, Ocean optics, Absorption, Tumors, Spectroscopy, Tissue optics

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The easy and non-destructive fluorescence method for quantification of early changes in biological tissues improves the possibilities of the clinical research and diagnostics. Developments in this area are moving very rapidly in part because of advances in the technology and in part because of the numerous successful examples which are appearing. New family of photomultiplier tubes with a high detection sensitivity for near-infra red light (700-900 nm) were developed as a result of project IMPECABLE, which are valuable tools for early diagnosis of cutaneous pigmented melanoma using long-wave fluorescence dyes. Several phthalocyanines that are promising fluorophores for photodiagnosis of cutaneous malignant melanoma have been studied in different solvents for concentrations from 10^-5 to 10^-15 mol. Argon pumped dye laser as an excitation source was used. Three different wavelengths (613, 633 and 660 nm) in the red region, corresponding to first absorption peak, minimum of the absorption and near to the Q-band maximum of Pcs were applied. Fluorescence signals in the region of 700 to 800 nm were detected using spectrometric systems (Perkin-Elmer, UK-with conventional PMT as a detector, and PC2000, Ocean Optics, USA-with CCD-array as a detector) and a newly developed red-sensitive PMT. Detectable signal from other spectrometric systems was obtain up to 10^-8 mol concentrations, which could be used for significant reduction of concentrations applied for in vivo applications. Fluorescence is a highly sensitive method of distinguishing between healthy and unhealthy tissue. The results demonstrate that extremely low concentrations of photosensitizers could be used to determine initial stages of melanoma. This application of PMT detectors will reduce extremely the negative side effects of higher concentrations of these drugs applied in the skin tissue. One can achieve high accuracy in the determination of pigmented malignant melanoma lesions with wide clinical applications.

Proceedings Article | 22 April 2005 Paper

Pulsed laser annealing of ion implanted insulators

Peter Townsend

Proceedings Volume 5830, (2005) https://doi.org/10.1117/12.617192

KEYWORDS: Nanoparticles, Pulsed laser operation, Ions, Annealing, Dielectrics, Particles, Absorption, Metals, Crystals, Diffusion

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Proceedings Article | 14 August 2001 Paper

Pulsed laser to improve the surfaces and ion implanted waveguides on Nd:YAG and LiNbO3

Gloria Vazquez, Peter Townsend

Proceedings Volume 4419, (2001) https://doi.org/10.1117/12.437081

KEYWORDS: Waveguides, Pulsed laser operation, Annealing, Ions, Nd:YAG lasers, Refractive index, Crystals, Laser therapeutics, Laser applications, Ion beams

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