A master oscillator configured as a seed laser for a laser optical module includes a reduced size, temperature controlled non-planar ring oscillator, a piezo-electric transducer mounted on the non-planar ring oscillator, a pump laser diode, and coupling optics configured to couple a laser output of the pump laser diode to an end face of the non-planar ring oscillator. The pump laser diode may operate as a single-mode pump.

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.

A microchip laser and a handpiece including the microchip laser. The microchip laser includes a laser medium with input and output facets. The input facet is coated with a highly reflective dielectric coating at microchip laser wavelength and highly transmissive at pump wavelength. The output facet is coated with a partially reflective at microchip laser wavelength dielectric coating. A saturable absorber attached by intermolecular forces to output facet of microchip laser. A handpiece for skin treatment includes the microchip laser.

A laser system may include a laser resonator configured to emit an input laser beam having an elliptical cross-sectional shape. The laser system also may include first reflective device configured to reflect the input laser beam to produce a first reflected laser beam. The first reflective device may include a spherical surface for reflecting the input laser beam. The laser system also may include a second reflective device configured to reflect the first reflected laser beam to produce a second reflected laser beam. The laser system also may include a coupling device configured to focus the second reflected laser beam to produce an output laser beam. The coupling device may include a spherical surface for receiving the second reflected laser beam. The laser system also may include an optic fiber configured to transmit the output laser beam for emission of the output laser beam onto a target area.

Apparatuses and methods are disclosed for applying laser energy having desired pulse characteristics, including a sufficiently short duration and/or a sufficiently high energy for the photomechanical treatment of skin pigmentations and pigmented lesions, both naturally-occurring (e.g., birthmarks), as well as artificial (e.g., tattoos). The laser energy may be generated with an apparatus having a resonator with the capability of switching between a modelocked pulse operating mode and an amplification operating mode. The operating modes are carried out through the application of a time-dependent bias voltage, having waveforms as described herein, to an electro-optical device positioned along the optical axis of the resonator.

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.

Provided is a method for producing a crystal fiber which can suppress the occurrence of stress birefringence even while distributing a light emission center so as to concentrate on a cross-sectional middle portion. The method for producing a crystal fiber comprises the steps of: using, as a preform, the crystal fiber comprising a light emission center that volatilizes from a melted portion upon the melting of a crystal, and heating a portion or a plurality of portions of the side of the preform, whereby the portion or the plurality of portions of the preform are melted such that only a given amount of the inside of the portion or the plurality of portions of the preform is not melted, to form the melted portion; and sequentially transferring the melted portion in the longitudinal direction of the preform, and cooling the melted portion, whereby the melted portion is continuously recrystallized to form a recrystallized region.

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