Abstract: A method is disclosed for transacting, purchasing and publishing copyrighted digital content that solves problems of the digital copyright that could not protect by methods of the prior art. The present invention allows various sales methods and licensing methods by using a copyrighted digital content description file, and effectively controls the user's use of the copyrighted digital content.

Abstract: A method is disclosed for transacting, purchasing and publishing copyrighted digital content that solves problems of the digital copyright that could not protect by methods of the prior art. The present invention allows various sales methods and licensing methods by using a copyrighted digital content description file, and effectively controls the user's use of the copyrighted digital content.

Abstract: A pulse compressor for solitons includes a continuous dispersive non-linear propagation structure so constructed so that the wavefront of an individual soliton pulse is steepened. In addition, the pulse compressor has a continuously reduced time constant on a spatial, as opposed to a temporal basis. Various structures of the pulse compressor are described.

Abstract: A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other.

Abstract: A solid state cyclotron laser device generate coherent electromagnetic radiation. A semiconductor configuration comprises an emitter region and a collector region separated by a base region and barrier layers on each side of the base. The semiconductor configuration is biased such that electrons enter the base region from the emitter region as hot electrons. A magnetic field applied by an external source to the base region causes the hot electrons to gyrate and quantize into Landau levels. An optical resonance cavity produces standing wave modes which stimulate the electrons to move from higher to lower Landau levels to generate conherent radiation. Electrons with decreased energy are removed at the collector in order to maintain the population inversion. The device is tunable by adjusting the magnetic field.