A method and a system for pulsed excitation of a nonlinear medium for photon pair generation, he method comprising exciting a single narrow resonance of a nonlinear resonant element with a pulsed laser field, comprising embedding a nonlinear resonant element directly into an external laser cavity and locking the cavity modes.

A surface-emitting laser array includes a plurality of light emitting parts. Each light emitting part includes a reflection mirror including aluminum gallium arsenide (Al.sub.xGa.sub.(1-x)As) where x is greater than 0.95 but less than or equal to 1; an active layer; and an electrode surrounding an emission region, from which laser light is emitted, the electrode covering a region between adjacent light emitting parts in the plurality of light emitting parts.

Embodiments are directed to a method for directly synthesizing graphene on a surface of a target object, which includes: forming a non-metal layer on a support substrate; disposing the target object in a space above the support substrate, which is opposite to the non-metal layer; and injecting a carbon precursor to form graphene on the surface of the target object to synthesize a graphene film, wherein the graphene is nucleated and grown by a decomposition of the carbon precursor, the carbon precursor is decomposed by heat with the catalytic assist from the non-metal layer, a carbon atom from the decomposition of the precursor is anchored on the surface to form the graphene film.

A method and apparatus for characterizing an optical element. The optical element is part of a laser and is mounted on a translation stage to scan the optical element transverse to an intracavity laser beam. A performance characteristic of the laser is recorded as a function of position of the optical element.

A method for in situ synthesis of graphene along a lengthwise direction of a waveguide applied to a photonic device includes processing an evanescent field of laser propagating in the waveguide to spread outward the waveguide, depositing a nickel thin film on a surface of the waveguide, growing graphene between a surface of the waveguide and a nickel thin film by irradiating telecommunication laser to a core of the waveguide, and removing the nickel thin film from the waveguide. Accordingly, graphene with high optical nonlinearity is in situ synthesized in the photonic device.

A laser apparatus according to the present invention may comprise: a plurality of reflection mirrors which form a resonance path so as for light to be amplified by an induced emission; a medium having a first surface which forms a vertical surface with respect to the resonance path, and a second interface which does not form a vertical surface with respect to the resonance path, and absorbs energy from a light source and amplifies and emits the light; and a saturable absorber having a second surface which forms a vertical surface with respect to the resonance path, and a second interface which does not form a vertical surface with respect to the resonance path, and generates ultrashort pulses. The laser apparatus according to the present invention has the effects of cutting a saturable absorber having a specific crystallographic axis to thereby make polarization capacity in one direction advantageous and minimize propagation loss. In addition, the laser apparatus according to the present invention has the effect of maximizing transmittivity maintenance capacity of polarization orientation in one direction by arranging a medium and a saturable medium so as to have a specific inclined plane.

A lidar system can include a solid-state laser to emit pulses of light. The solid-state laser can include a Q-switched laser having a gain medium and a Q-switch. The lidar system can also include a scanner configured to scan the emitted pulses of light across a field of regard and a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system. The lidar system can also include a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time of flight for an emitted pulse of light to travel from the lidar system to the target and back to the lidar system.

The present disclosure discloses a saturable absorber mirror of a composite structure, including: a substrate; a buffer layer on the substrate; a distributed Bragg reflective mirror on the buffer layer; a quantum dot or quantum well saturable absorber body on the distributed Bragg reflective mirror; a graphene saturable absorber body on the quantum dot or quantum well saturable absorber body. In the present disclosure, the graphene saturable absorber body is composited with the quantum dot saturable absorber body or the quantum well saturable absorber body to be used as the saturable absorber body in the saturable absorber mirror of the present disclosure. A thermal damage threshold and an optical property stability of the saturable absorber body are improved, and an ultrafast laser pulse with high power and short pulse mode locking, a stable output repetition cycle, a narrow pulse width, and a short response time is implemented.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument for biological or chemical analyses. The pulsed laser may produce sub-100-ps optical pulses at a repetition rate commensurate with electronic data-acquisition rates. The optical pulses may excite samples in reaction chambers of the instrument, and be used to generate a reference clock for operating signal-acquisition and signal-processing electronics of the instrument.

To provide a laser ignition device in which the ignition efficiency is improved and the laser pulse energy necessary for ignition is minimized by optimizing the pulse time width of laser. The laser ignition device includes: a pulse laser oscillator 1 configured to output a beam having a wavelength [m] and a beam quality M.sup.2; an energy controller 2 configured to control energy of pulse laser outputted from the pulse laser oscillator 1; a lens 3 having a focal length f [mm] and configured to focus the pulse laser outputted from the pulse laser oscillator 1; and a pulse time width controller 14 configured to control a time width of the pulse laser, wherein the pulse time width controller 14 controls the time width of the pulse laser to be 0.6 to 2 ns.