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.

An optical parametric device (OPD), which is selected from an optical parametric oscillator (OPO) or optical parametric generator (OPG), is configured with a nonlinear optical element (NOE) which converts an incoupled pump radiation at first frequency into output signal and idler radiations at one second frequency or different second frequencies, which is/are lower than the first frequency, by utilizing nonlinear interaction via a random quasi-phase matching process (RQPM-NOE). The NOE is made from a nonlinear optical material selected from optical ceramics, polycrystals, micro and nanocrystals, colloids of micro and nanocrystals, and composites of micro and nanocrystals in polymer or glassy matrices. The nonlinear optical material is prepared by modifying a microstructure of the initial sample of the NOE such that an average grain size is of the order of a coherence length of the three-wave interaction which enables the three wave nonlinear interaction with a highest parametric gain achievable via the RQPM process

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.

The present invention provides systems and methods for optical frequency comb generation with self-generated optical harmonics in mode-locked lasers for detecting the carrier envelope offset frequency. The mode-locked laser outputs an optical frequency comb and a harmonic output. The harmonic output provides an optical heterodyne resulting in a detectable beat note. A carrier envelope offset frequency detector detects the beat note and generates an optical frequency comb signal. The signal can be used to stabilize the optical frequency comb output.

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.

The present invention demonstrates a technique for achieving milli-joule level and higher energy, broad bandwidth laser pulses centered around 2.4 micrometer with a kilohertz and other repetition rate. The key to such technique is to start with a broadband micro-joule level seed laser at around 2.4 micrometer, which could be generated through difference frequency generation, four-wave mixing process and other methods. This micro-joule level seed laser could then be amplified to above one milli-joule through chirped pulse amplification in a Cr2+:ZnSe or Cr2+:ZnS crystal pumped by a commercially available Ho:YAG or other appropriate suitable lasers. Due to the high seed energy, fewer gain passes are needed to achieve a milli-joule level output thus significantly simplifies laser architectures. Furthermore, gain narrowing effect in a typical chirped pulse amplifier is also mitigated and thus enable a broadband output.

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 structure can include a III-N layer with a first lattice constant, a first rare earth pnictide layer with a second lattice constant epitaxially grown over the III-N layer, a second rare earth pnictide layer with a third lattice constant epitaxially grown over the first rare earth pnictide layer, and a semiconductor layer with a fourth lattice constant epitaxially grown over the second rare earth pnictide layer. A first difference between the first lattice constant and the second lattice constant and a second difference between the third lattice constant and the fourth lattice constant are less than one percent.

A Kerr Mode Locked (KLM) laser is configured with a resonant cavity. The gain medium, selected from polycrystalline transition metal doped II-VI materials (TM:II-VI), is cut at a normal angle of incidence and mounted in the resonant cavity so as to induce the KLM laser to emit a pulsed laser beam at a fundamental wavelength. The pulses of the emitted laser beam at the fundamental wavelength each vary within a 1.8-8 micron (m) wavelength range, have a pulse duration equal to or longer than 30-35 femtosecond (fs) time range and an average output power within a mW to about 20 watts (W) power range. The disclosed resonant cavity is configured with a plurality of spaced apart reflectors, two of which flank and are spaced from the gain medium which is pumped to output a laser beam at a fundamental wavelength and its higher harmonic wavelengths. The gain medium is mounted on a translation mechanism operative to controllably displace the gain medium along a waist of the laser beam. The displacement of the gain medium causes redistribution of a laser power between a primary output at the fundamental wavelength and at least one secondary output at the higher harmonic wavelength.

A vertical cavity surface emitting laser (VCSEL) is formed on a substrate. The VCSEL includes a layer structure and one or more distributed Bragg reflector (DBR) mirrors formed on at least one of the layer structure or the substrate. The layer structure generates an optical signal at a first wavelength based on a control current received from a transistor that is formed on the substrate. Rare earth ions (REIs) are deposited in the one or more DBR mirrors such that the one or more DBR mirrors receive the optical signal at the first wavelength and generate the optical signal at a second wavelength.