A light source for high power coherent light can include multiparticle relativistic bunches of electrons generating high intensity propagating fields. Coherent emission between electrons may also be utilized. The source may be independent of any medium or media to remove all constraints on the wavelength of the light emitted. And at least a portion of a single alternating magnetic field for accelerating the electron bunches can be included. The color or wavelength of the produced light can be determined solely by the parameters of the electron bunches and the alternating field. The source can be used for imaging, such as medical imaging or for security, including concealed weapons, and for quality control.

A light source for high power coherent light can include multiparticle relativistic bunches of electrons generating high intensity propagating fields. Coherent emission between electrons may also be utilized. The source may be independent of any medium or media to remove all constraints on the wavelength of the light emitted. And at least a portion of a single alternating magnetic field for accelerating the electron bunches can be included. The color or wavelength of the produced light can be determined solely by the parameters of the electron bunches and the alternating field. The source can be used for imaging, such as medical imaging or for security, including concealed weapons, and for quality control.

The apparatus and the method for terahertz-based reading of data recorded in the Ruderman-Kittel-Kasuya-Yosida (RKKY)-based magnetic memory provided. The apparatus comprises: a Terahertz Magnon Laser configured to generate THz magnons; wherein the Terahertz Magnon Laser further comprises a Magnon Gain Medium (MGM) configured to support generation of non-equilibrium Terahertz magnons after the electric current is applied across the Terahertz Magnon Laser. The apparatus further comprises a magnetic reading bridge coupled to the Magnon Gain Medium of the Terahertz Magnon Laser; the magnetic reading bridge also coupled to a Ruderman-Kittel-Kasuya-Yosida (RKKY)-based magnetic memory cell; wherein magnetization of the magnetic reading bridge is induced by the overall magnetization of the RKKY)-based magnetic memory cell, and wherein the overall magnetization of the RKKY)-based magnetic memory cell is dependent on the information bit encoded into the magnetic memory cell, and wherein the encoded bit ‘1’ corresponds to the higher overall magnetization of the memory cell, and wherein the encoded bit ‘0’ corresponds to the lower overall magnetization of the memory cell. The apparatus further comprises a terahertz demodulator configured to demodulate the generated THz reading signal; wherein the higher detected THz frequency corresponds to reading bit ‘1’ encoded into the RKKY-based magnetic memory cell; and wherein the lower detected THz frequency corresponds to reading bit ‘0’ encoded into the RKKY-based magnetic memory cell.

An apparatus for generation of tunable terahertz radiation is provided. The apparatus comprises: a plurality of terahertz magnon laser generators, whereas at least one such terahertz magnon laser generator comprises a multilayer column, and a terahertz transparent medium separating at least two such terahertz magnon laser generators. At least one such multilayer column further comprises: a substrate, a bottom electrode coupled with the substrate, a bottom layer coupled with the bottom electrode, a tunnel junction coupled with the bottom layer, a top layer coupled with the tunnel junction, a pinning layer coupled with the spin injector, and a top electrode coupled with the pinning layer.

Disclosed is a laser system including a first laser and a second laser. The first laser includes a laser cavity, and a gas phase molecular gain medium disposed in the laser cavity, the gain medium having an absorption band. The second laser is a solid state laser configured to be continuously tunable, with respect to an emission wavelength of the second laser, over the absorption band of the gain medium, and the second laser is tuned to pump rotational vibrational transitions in the gain medium to achieve a rotational population inversion.

A method for tuning the frequency of THz radiation is provided. The method utilizes an apparatus comprising a spin injector, a tunnel junction coupled to the spin injector, and a ferromagnetic material coupled to the tunnel junction. The ferromagnetic material comprises a Magnon Gain Medium (MGM). The method comprises the step of applying a bias voltage to shift a Fermi level of the spin injector with respect to the Fermi level of the ferromagnetic material to initiate generation of non-equilibrium magnons by injecting minority electrons into the Magnon Gain Medium. The method further comprises the step of tuning a frequency of the generated THz radiation by changing the value of the bias voltage.

A plasmonic laser array device may comprise a first microcavity element having a first radiating end facet and a second radiating end facet opposite the first radiating end facet in a longitudinal direction of the device. The device may comprise a second microcavity element having a third radiating end facet and a fourth radiating end facet opposite the third radiating facet in the longitudinal direction. The device may comprise a first microcavity gap configured to separate the first microcavity element and the second microcavity element in the longitudinal direction. The device may comprise a bottom (e.g., metal) layer configured to underly the first microcavity element, the second microcavity element, and the first microcavity gap. The device may comprise an arrangement that places the first microcavity element and the second microcavity element into a phase-locked orientation for a phased-locked operation of the plasmonic laser array device.

A quantum cascade laser includes a semiconductor substrate and an active layer having a cascade structure, in which unit layered bodies, each composed of a quantum well light emitting layer and an injection layer, are stacked, wherein the unit layered body has a subband level structure having an upper laser level, a lower laser level, and a relaxation miniband composed of at least two energy levels with an energy spacing smaller than the energy difference (E.sub.UL) between the upper laser level and the lower laser level, the energy width of the relaxation miniband is smaller than the energy (E.sub.LO−E.sub.UL) obtained by subtracting the energy difference (E.sub.UL) from the energy (E.sub.LO) of longitudinal optical phonons, and electrons subjected to the intersubband transition are relaxed in the relaxation miniband and are injected into a quantum well light emitting layer in a subsequent unit layered body.

A quantum cascade laser includes a semiconductor substrate, an optical waveguide formed on a first surface of the semiconductor substrate, and a temperature adjusting member. The optical waveguide includes a first region and a second region located on one side with respect to the first region in the optical waveguide direction of the optical waveguide. The first region generates a first light having a first wavelength, and the second region generates a second light having a second wavelength. The optical waveguide generates an output light having a frequency corresponding to a difference between the first wavelength and the second wavelength by difference-frequency generation. A recess for suppressing heat transfer between the first region and the second region is formed at a second surface of the semiconductor substrate. The temperature adjusting member includes a first temperature adjusting member for adjusting the temperature of the second region.

Aspects of the present disclosure relate to receiving and emitting Terahertz (THz) electromagnetic radiation via one or more Josephson Junction(s) electronically coupled to an antenna structure. Aspects of the present disclosure further relate to a mechanism and methods to analyze a gas and/or identifying a gas (and/or suspension) based its electromagnetic absorption. Together, THz electromagnetic radiation may be emitted from one or more Josephson Junction emitters (transmitters), passed through a gas/suspension of interest, and non-absorbed THz electromagnetic radiation may be detected from one or more Josephson Junction detectors (receivers).