An oscillation device includes a waveguide structure including a first conductor layer, a second conductor layer, and a semiconductor layer disposed between the first conductor layer and the second conductor layer and having a gain of an electromagnetic wave, an antenna unit configured to radiate the electromagnetic wave, a first connecting portion configured to connect the waveguide structure and the antenna unit, and a second connecting portion configured to connect the waveguide structure and the antenna unit. A first connecting position of the first connecting portion and the waveguide structure and a second connecting position of the second connecting portion and the waveguide structure are different from each other in a resonance direction in which the electromagnetic wave that resonates the waveguide structure resonates.

An improved longwave infrared quantum cascade laser. The improvement includes a strained In.sub.xGa.sub.1-xAs/Al.sub.yIn.sub.1-yAs composition, with x and y each between 0.53 and 1, an active region emitting at a wavelength equal to or greater than 8 m, an energy spacing E.sub.54 equal to or greater than 50 meV, an energy spacing E.sub.C4 equal to or greater than 250 meV, and an optical waveguide with a cladding layer on each side of the active region. Each cladding layer has a doping level of about 2.Math.10.sup.16 cm.sup.3. The optical waveguide also has a top InP layer with a doping level of about 5.Math.10.sup.16 cm.sup.3 and a bottom InP layer with a doping level of about 510.sup.16 cm.sup.3. Additionally, the optical waveguide has a plasmon layer with a doping level of about 8.Math.10.sup.18 cm.sup.3.

The present invention provides a new approach for subwavelength cavity solutions. Employment of a reflecting metasurface based on plasmonic nanostructure elements changes the cavity resonance condition that currently causes restrictions on minimum length. The short length of wave propagation between the cavity walls is compensated by strong localization of electromechanical energy near the metasurface walls, which experience considerable phase shifts over a very small distance. Subwavelength 2D and 3D cavities find implementation as laser sources, optical parametric oscillators, interferometers, laser phase and frequency stabilizers, laser spatial and temporal filters, adaptive beam, and pulse shaping devices.

This invention concerns the design of an optical frequency comb, i.e. a laser whose spectrum consists of a series of discrete, equally spaced frequency lines, based on a quantum cascade laser (QCL), in particular to a waveguide design which controls the dispersion. To achieve this, the active region of the laser is sandwiched between two highly doped plasmon layers. This novel structure is particularly advantageous for mass-produced optical frequency comb QCLs.

Various embodiments may provide a topological laser. The topological laser may include a photonic structure configured to generate a laser beam upon electrical pumping of the photonic structure. The laser beam may be based on photonic Majorana zero mode. The laser beam may be a cylindrical vector beam. The topological laser may be configured to provide single mode operation.