Abstract: In a method for fabricating imaging apparatus, adjoining regions, each forming only part of the active area of the complete device, are laid down separately, enabling larger active areas to be produced than would otherwise be possible using conventional wafer stepper equipment. In the complete device, imaging may be arranged over the boundary between the regions and/or charge may be transferred across the boundary.

Abstract: A thermal camera is mounted within a helmet and is arranged such that the optical path in free space from its output is wholly within the volume defined by the helmet and the helmet faceplate. The output iminges on a concave mirror/lens combination located below the wearer's sightline. The arrangement is particularly suitable for fire fighting and search and rescue applications.

Abstract: A magnetron is tuned by a co-axial transmission line co-axial with the axis of the magnetron and a radial transmission line linking the co-axial line to a plurality of sampling points symmetrically positioned on the end of the magnetron. A fraction of the R.F. power in the magnetron passes into the transmission lines and vice versa, so by altering the resonant frequency of the transmission lines the frequency of the RF power in the magnetron can be controlled.

Abstract: A CCD imaging array includes one or more shift registers. By injecting a charge packet at one end of the shift register, at times related to the start of line read out, then the charge packet reaches the other end of the shift register at the end of the line period. Thus the shift register can be used to generate line synchronization signals. The technique can also be applied for more complex waveform generation and for field generation.

Abstract: The performance of a magnetron may be degraded by its output frequency changing. This degradation may be reduced by fixing a resonator element in the magnetron's output waveguide enabling temperature stabilization to be achieved and also permitting the output spectrum of the radiation to be narrowed.

Abstract: In a thyratron gas discharge device, magnetic material is located coaxially with the anode to produce a magnetic field between the anode and cathode which is substantially parallel to a discharge established between them. This causes electrons emitted from the cathode to have longer path lengths than would otherwise be the case and so the ionization density within the device is increased. This improved this operating characteristics of the thyratron and results in greater utilization of the cathode.

Abstract: Metal vapor laser apparatus includes an envelope within which is contained electrodes and a plurality of cylindrical copper segments arranged between them. During operation of the laser, bromine and helium buffer gas are arranged to flow through the envelope, causing copper bromide to be produced. When a discharge is established between the electrodes, the copper bromide vaporizes and dissociates to give copper vapor which is then excited to produce a population inversion. Such apparatus is able to operate at relatively low temperatures, in the region of 600.degree. C.

Abstract: Laser apparatus including a relatively long cylindrical cathode within a discharge tube containing a buffer gas at a low pressure of less than 1 Torr. By employing a laser constructed according to the invention, it is possible to achieve a plasma which extends along the length of the cathode, which may be up to one meter long.

Abstract: In a laser arrangement, solid or liquid material, at least part of which comprises a laser amplifying medium, is atomized in a gas prior to being applied to a discharge region. In one embodiment of the invention, the gas is combustible and is ignited to produce a flame which provides heating of the material. The invention is particularly applicable to metal vapour lasers.In another embodiment of the invention, the material is atomized in an inert gas and a discharge within a laser discharge tube is used to provide excitation.