A method for preparing an erbium (Er)- or erbium oxygen (Er/O)-doped silicon-based luminescent material emitting a communication band at room temperature. The method comprising the following steps: (a) doping a single crystalline silicon wafer with erbium ion implantation or co-doping the single crystalline silicon wafer with erbium ion and oxygen ion implantation simultaneously to obtain an Er- or Er/O-doped silicon wafer, wherein the single crystalline silicon wafer is a silicon wafer with a germanium epitaxial layer, or an SOI silicon wafer with silicon on an insulating layer or other silicon-based wafers; and (b) subjecting the Er- or Er/O-doped silicon wafer to a deep-cooling annealing treatment, the deep-cooling annealing treatment includes a temperature increasing process and a rapid cooling process.

Optical gain mediums are required for lasing devices and high intensity optical systems across a wide range of applications. A method for achieving optical gain includes an optical gain medium having colloidal quantum fountains includes providing pump radiation to the gain medium. The electrons of the colloidal quantum fountains are promoted from a valence band to an excited state in a conduction band of the colloidal quantum fountains. Seed radiation is provided to the gain medium and electrons of the quantum fountains are de-excited by the seed radiation through stimulated emission from the excited state to a lower energy state of the conduction band, thereby providing optical gain.

A single-mode micro-laser based on a single whispering gallery mode optical microcavity and a preparation method thereof described includes: preparing a desired single whispering gallery mode optical microcavity doped with rare earth ions or containing a gain material such as quantum dots, wherein an optical microcavity configuration include a micro-disk cavity, a ring-shaped microcavity, and a racetrack-shaped microcavity; a material type include lithium niobate, silicon dioxide, silicon nitride, etc.; preparing an optical fiber cone or an optical waveguide of a required size which can excite high-order modes of the optical microcavity, such as a ridge waveguide and a circular waveguides; and coupling, integrating, and packaging the optical fiber cone or the optical waveguide with the microcavity. A pump light is coupled to the optical fiber cone or the optical waveguide to excite a compound mode with a polygonal configuration.

Self-isolated lasers are provided by using a chiral metasurface in combination with a spin-selective gain medium and symmetry-breaking (i.e., not linearly polarized) optical pumping. In preferred embodiments the chiral metasurface is resonant, thereby proving an integrated optical resonator to support lasing. The chiral metasurface can be the spin-selective gain medium, or it can be formed on a surface of the spin-selective gain medium, or it can be distinct from the spin-selective gain medium.

A CW laser with a rotating ring gain element is disclosed. The ring is pumped at multiple locations and the laser generates a mid-IR output. Multiple pumped gain portions of the ring provide a power scaled output. The gain portions may be positioned in a single resonator cavity, in multiple resonator cavities, and in MOPA architectures with associated focusing, folding, and combining optical elements.

A method of treating a substrate comprises applying an electric field to a substrate comprising a layer of a dopant on at least one surface; applying a predetermined temperature to the substrate in the electric field; applying the electric field and the predetermined temperature for a time sufficient to induce migration of the dopant into the substrate to provide a doped substrate; and removing the electric field and returning the doped substrate to about room temperature, wherein the doped substrate is characterized in that a spectral laser output of the doped substrate exhibits a nominally single frequency having a linewidth less than about 5 nm. The substrate may be a glass material, a single crystal material, a poly-crystalline material, a ceramic material, or a semiconductor material, which may be optically transparent. Before treatment, the substrate may be an undoped substrate or a doped substrate.

Typically, quantum systems are very sensitive to environmental fluctuations, and diagnosing errors via measurements causes unavoidable perturbations. Here, an in situ frequency-locking technique monitors and corrects frequency variations in single-photon sources based on resonators. By using the classical laser fields used for photon generation as probes to diagnose variations in the resonator frequency, the system applies feedback control to correct photon frequency errors in parallel to the optical quantum computation without disturbing the physical qubit. Our technique can be implemented on a silicon photonic device and with sub 1 pm frequency stabilization in the presence of applied environmental noise, corresponding to a fractional frequency drift of <1% of a photon linewidth. These methods can be used for feedback-controlled quantum state engineering. By distributing a single local oscillator across a one or more chips, our approach enables frequency locking of many single photon sources for large-scale photonic quantum technologies.

A power semiconductor waveguide optical amplifier (P-SWA) may include an amplifier waveguide with an invertible core formed from one or more undoped heterogeneous semiconductor layers and one or more cladding layers surrounding one or more sides of the invertible core formed as one or more undoped semiconductor layers. Pump light may be coupled into the amplifier waveguide to induce the population inversion in the invertible core. Signal light may further be coupled into the amplifier waveguide and may be amplified as it propagates through the amplifier waveguide. The signal light may then exit the amplifier waveguide as amplified signal light.

Disclosed is a terahertz laser device based on phonon vibration excitation, including a resonant cavity composed of a hollow waveguide made of a composite film and optical lenses at both ends of the waveguide, where M represents nano-metal particles. A zinc oxide mesomorphic microsphere is used herein as a source, symmetric stretching vibration of nanosheets on the zinc oxide microsphere is excited and induced by a laser and is transmitted through elastic and electric coupling among the nanosheets, and a terahertz wave with a frequency of 0.36 THz is radiated by means of phonon vibration; moreover, the zinc oxide mesomorphic microspheres and the nano-metal particles are mixed evenly to produce a strong local electric field a few nanometers nearby a surface of the metal particle by taking advantage of a surface-enhanced Raman effect of the nano-metal particles, a nanocantilever of the ZnO mesomorphic microsphere is greatly changed in polarizability with ample contact of the nano-metal particles and the ZnO mesomorphic microspheres, and thus the terahertz radiation power thereof is enhanced.

A CW laser with a rotating ring gain element is disclosed. The ring is pumped at multiple locations and the laser generates a mid-IR output. Multiple pumped gain portions of the ring provide a power scaled output. The gain portions may be positioned in a single resonator cavity, in multiple resonator cavities, and in MOPA architectures with associated focusing, folding, and combining optical elements.