Abstract: A nonlinear solid-state device useful for frequency conversion of electromagnetic radiation and in particular for harmonic generation, comprising a waveguiding electromagnetically distributed structure (WEDS) which includes monolithically a synthetic nonlinear material (SNM). Input radiation coupled into the WEDS is converted into a higher frequency output radiation through a constricted oscillatory motion of charge carriers and phase matched harmonic frequency generation of radiation which builds up coherently over an interaction length many time larger than the radiation wavelengths. In one embodiment, microwave radiation is converted into terahertz radiation. In other embodiments, SNM based WEDS devices are adapted for frequency mixing and parametric oscillation.

Abstract: A nonlinear solid-state device useful for frequency conversion of electromagnetic radiation and in particular for harmonic generation, comprising a waveguiding electromagnetically distributed structure (WEDS) which includes monolithically a synthetic nonlinear material (SNM). Input radiation coupled into the WEDS is converted into a higher frequency output radiation through a constricted oscillatory motion of charge carriers and phase matched harmonic frequency generation of radiation which builds up coherently over an interaction length many time larger than the radiation wavelengths. In one embodiment, microwave radiation is converted into terahertz radiation. In other embodiments, SNM based WEDS devices are adapted for frequency mixing and parametric oscillation.

Abstract: A free electron laser for use with a short-pulse relativistic electron source. The device includes a resonant optical cavity in which a spatially-periodic magnetic field is produced by a wiggle magnet assembly. An input optical beam having a wavelength lying within the gate bandwidth of the free electron laser interaction is injected into the cavity. A beam of relativistic electrons produced by a short-pulse source, such as an RF-linac, is injected into the cavity. The electron beam and the input optical beam interact under the influence of the magnetic field to amplify the input optical beam.

Abstract: Free-electron lasers and masers are modified by eliminating the resonator cavity as such. The feedback mechanism, essential to oscillation, is distributed through and integrated with the transmission line which guides the electromagnetic wave at the active region where interaction with the electron beam takes place. The feedback structure is created by perturbations in the transmission line along the length thereof at the locations of the zero electric field lines of a desired oscillatory standing wave mode. The perturbations may take the form of axial, helical, and azimuthal deformation of the transmission line.

Abstract: An electrostatic free electron laser having an electromagnetic waveguide, means to produce a periodic longitudinal electrostatic field along the waveguide and an electron beam which passes through the waveguide. Radiative energy is generated by the laser as a result of the kinetic energy lost by the electron beam as it is decelerated during its interaction with the electromagnetic wave and the electrostatic field within the waveguide. In use as an oscillator, the electrostatic free electron laser includes a resonator either in addition to or instead of the waveguide.

Abstract: A monolithic PNPN injection laser diode operating as an optical repeater is comprised of a direct band-gap semiconductor material, such as essentially GaAs, epitaxially grown in five layers with the first, third and fifth layers of GaAsAl and the second and fourth layers of GaAs, and all layers suitably doped to effectively form two complementary transistors interconnected for regenerative feedback between them with the second layer forming the base of one transistor and the collector of the other transistor, and the third layer forming the base of the other transistor and the collector of the one transistor. The PNPN laser diode thus produced has a V-I negative resistance characteristic. The second and fourth layers produce coherent laser beams in response to a light pulse received while the laser diode is biased off with its load line below its breakover voltage, thus switching the laser diode on.