The piezoelectric and pyroelectric polymer poly(vinylidene fluoride) (PVF2) was recently classified as a polymeric ferroelectric. The physical properties of PVF2 are reviewed to justify this definition. Applications are classified on the basis of transduction mechanism including electrical to mechanical, mechanical to electrical, thermal to mechanical, thermal to electrical, and optical to mechanical. Applications in each of these classifications are surveyed, and advantages and disadvantages of using polymeric ferroelectrics rather than more conventional materials are described.

Ferroelectric polymers and their applications

A lighting system, particularly for use in extreme ultraviolet (EUV) lithography, comprising a projection lens for producing semiconductor elements for wavelengths ≤ 193 nm is provided with a light source (1), an object plane (12), an exit pupil (15), a first optical element (5) having first screen elements (6) for producing light channels, and with a second optical element (7) having second screen elements (8). A screen element (8) of the second optical element (7) is assigned to each light channel that is formed by one of the first screen elements (6) of the first optical element (5). The screen elements (6) of the first optical element (5) and of the second optical element (7) can be configured or arranged so that they produce, for each light channel, a continuous beam course from the light source (1) up to the object plane (12). The angles of the first screen elements (6) of the first optical element (5) can be adjusted in order to modify a tilt. The location and/or angles of the second screen elements (8) of the second optical element (7) can be adjusted individually and independently of one another in order to realize another assignment of the first screen elements (6) of the first optical element (5) to the second screen elements (8) of the second optical element (7) by displacing and/or tilting the first and second screen elements (8).

Lighting system, particularly for use in extreme ultraviolet (euv) lithography

A closed loop system sends one portion of a coherent laser beam along a first path and another portion of the beam along a second path which is directed at a mirror formed on piezoelectric membrane. After reflection, both return beams are mixed on a photodetector array and the array output is analyzed to determine the values of a charge distribution on the piezoelectric membrane which will null or maintain constant the phase of the mixed beam.

Wavefront sensing and correction with deformable mirror

This thesis explores the barriers to accessing primary care health service provision for \nGypsies and Travellers in England. Research took place 'in two phases. The first was a \nqualitative study of Gypsies' and Travellers' cultural beliefs, attitudes, perceptions of \nand access to health care. Findings included low expectations and poor experience of \nservices, as well as many examples of communication barriers between Gypsies and \nTravellers and health staff. The second phase built on these findings, by adopting \nparticipatory action research (PAR) methods, to explore communication processes \nfrom both staff and Gypsy and Traveller perspectives. The aim was to elicit \nunderstanding with a view to exploring how barriers might be overcome. \nBoth phases ofresearch show how Gypsy and Traveller experiences of discrimination \nand racism contribute to a sense ofdevalued identity, characterised by feelings of \nshame and humiliation. Shame and attempts to ward off shame are central features of \nrelationships and encounters with health staff as personal reactions to these \nexperiences can produce mutual mistrust and poor relations between staff and the \nGypsy and Traveller patients. At the same time, health staff reactions are shaped by \npressures related to role, status and setting. By focusing on processes of coconstructed \ncommunication, I identify specific patterns of tension and mistrust. \nIn conclusion, I argue that a reflective and collaborative staff approach in primary \ncare, based on effective leadership and a shared team ethos, can provide the empathic \nfocus needed as a starting-point for trust and effective communication. I also argue \nthat acquisition of good communication skills and development of experiential \ncultural awareness, whilst essential, are insufficient to guarantee cultural competence. \nA reflexive approach, focussing on personal qualities, values, beliefs and attitudes, is \nalso essential for cultural safety. I outline the specific staff training implications of \nthese findings, in terms of ensuring culturally safe health care for Gypsies and \nTravellers.

Abstract of thesis: Gypsies and Travellers accessing primary health care: interactions with health staff and requirements for ‘culturally safe’ services

Polyvinylidene fluoride—piezoelectric polymer for integrated infrared optics applications

First a transmission-type optical element, which modulates the phase of the incident wave field in a 1-D manner, is proposed, then several such elements are combined in a cascade to construct an adaptive transmission-type 2-D phase modulator. The element consists of a deformable glass plate made by bonding an appropriately shaped PVDF piezoelectric film with transparent electrodes to a laminar glass plate, a plane glass plate, and a medium immersed between the two plates. The construction of the modulator, complementary methods to improve the characteristics, several basic experimental results, and its use to compensate for aberrations in an imaging system are given. The modulator constructed can generate wave fronts whose phase profile is expressed by the functional form ax(2) + by(2) + cxy.

Transmission-type PVDF 2-D optical phase modulator.

The angles between neighboring small mirror elements are controlled by the signals from a microcomputer through properly arranged bimorph actuators so that an effective deformable mirror system is realized. This system has the following special features: (a) The surface of the mirror is continuous, and only the angles at the connecting edges between neighboring mirror segments are changed. This results in a smooth and largely deformable mirror surface with a smaller number of elemental mirrors than the conventional COAT system. (b) The errors in the mirror system, introduced in the fabrication of each mirror element and in the construction of the system, can be compensated by properly controlling the voltages supplied to the bimorphs. The information about these errors is obtained by previous measurements and stored in the computer. An experimental system was constructed, and some experimental results are shown. The results show the effectiveness of the method.

Yoshifumi Ueda

Papers

Transmission-type PVDF 2-D optical phase modulator.

Computer-aided deformable-mirror system using differential angle control.