Abstract: A multilayer film article is disclosed. The film includes an infrared light reflecting multilayer film having alternating layers of a first polymer type and a second polymer type and an infrared light absorbing or reflecting layer adjacent the multilayer film. The film includes a multilayer stack composed of alternating optical layers of first and second diverse polymers A, B. The optical layers when counted from one end of a first effective optical packet form a plurality of unit cells each having six optical layers arranged in relative optical thicknesses in a first cyclic permutation of 7A1B1A7B1A1B. At normal incidence the first effective optical packet provides a reflection band at infrared wavelengths and substantially transmits light at visible wavelengths.

Abstract: A multilayer film article is disclosed. The film includes an infrared light reflecting multilayer film having alternating layers of a first polymer type and a second polymer type and an infrared light absorbing or reflecting layer adjacent the multilayer film. The film includes a multilayer stack composed of alternating optical layers of first and second diverse polymers A, B. The optical layers when counted from one end of a first effective optical packet form a plurality of unit cells each having six optical layers arranged in relative optical thicknesses in a first cyclic permutation of 7A1B1A7B1A1B. At normal incidence the first effective optical packet provides a reflection band at infrared wavelengths and substantially transmits light at visible wavelengths.

Abstract: A film includes a multilayer stack composed of unit cells having alternating optical layers of first and second diverse polymers A,B. The unit cells can consist essentially of two (AB), four (2A1B2C1B), or six layers (7A1B1A7B1A1B). The layers form an effective optical packet disposed between non-optical layers, the beginning and ending optical layers of which are selected to control an optical figure of merit such as spectral noise in the visible region. The arrangement of layers beginning at one end of the effective optical packet defines a specific cyclic permutation of the unit cell layer order, which provides a better figure of merit than an effective optical packet of similar design but having a different cyclic permutation.

Abstract: A film includes a multilayer stack composed of unit cells having alternating optical layers of first and second diverse polymers A, B. The unit cells can consist essentially of two (AB), four (2A1B2C1B), or six layers (7A1B1A7B1A1B). The layers form an effective optical packet disposed between non-optical layers, the beginning and ending optical layers of which are selected to control an optical figure of merit such as spectral noise in the visible region. The arrangement of layers beginning at one end of the effective optical packet defines a specific cyclic permutation of the unit cell layer order, which provides a better figure of merit than an effective optical packet of similar design but having a different cyclic permutation.

Abstract: A magnetic pole head for recording and playback is described. Its features, as illustrated in FIG. 1 are: a high permeability core 1, a magnetic field producing means 3, and an acute angle .phi. between the bottom surface and side surface at the trailing portion of the head (i.e. the portion which influences the recording medium 5 last). It has been found that this improved pole head significantly increases the derivative of vertical magnetic field intensity with respect to lateral distance. This increase in the rate at which vertical field intensity changes will allow for higher density perpendicular recording than is feasible with conventional vertical heads.

Abstract: A charged particle beam (e.g., ions or electrons) apparatus including two electrostatic focusing lenses and an electrode having a diameter limiting aperture positioned between the lenses is further provided with two electrode assemblies which interact with an extractor electrode and with a source of charged particles such that the trajectories of the particles in the beam passing through the second of the two assemblies are substantially parallel. This feature and other disclosed improvements facilitate the production of a substantially monoenergetic beam which under a first set of conditions can be focused to provide a small-diameter, spherical-aberration limited beam and which under another set of conditions, can be focused to provide a high current beam.