The invention discloses a visible laser apparatus including a linear cavity. The linear cavity includes along the first direction: a first optical component, a gain medium, a second optical component, a Raman crystal, a double-harmonic crystal and a third optical component. The first optical component receives an incident pumping light in the first direction. The gain medium receives the pumping light from the first optical component, and generates a first infrared base laser having a first wavelength. The second optical component has a first high transmittance in a first wave band including the first wavelength in the first and the second directions. The Raman crystal receives the first infrared base laser, and generates a second infrared base laser having a second wavelength. The double-harmonic crystal receives the first and the second infrared base lasers, and generates a visible laser light having a third wavelength.

A method, apparatus, and system for non-linear optical process. A first light of a first wavelength is routed in a first loop in a main nonlinear optical waveguide. The first loop has a first length for the first light of the first wavelength. A second light of a second wavelength is routed in a second loop that includes portions of the main nonlinear optical waveguide and a first extension optical waveguide. The second loop has a second length for the second light of the second wavelength. A third light of a third wavelength is routed in a third loop that include portions of the main nonlinear optical waveguide and a second extension optical waveguide. The third loop has a third length for the third light of the third wavelength.

An optical waveguide structure comprises a first coupler and a second coupler that, in combination, direct a first-wavelength light to travel through a nonlinear-optical waveguide, the two couplers and an extension waveguide but not a secondary waveguide, a first resonator loop is defined for which the first-wavelength light is resonant. The two couplers, in combination, also direct a second-wavelength light to travel through the nonlinear-optical waveguide, the two couplers and the secondary waveguide but not the extension waveguide, wherein a different second resonator loop is defined for which the second-wavelength light is resonant.

An optical waveguide structure comprises a nonlinear optical waveguide comprising a nonlinear optical material having a second order nonlinear coefficient that changes with a direction of light propagation. A first portion of the nonlinear optical waveguide in which a light propagating through the first portion is affected by a positive value of a second order nonlinear coefficient. A second portion of the nonlinear optical waveguide in which the light propagating through the first portion is affected by a negative value of a second order nonlinear coefficient, wherein a set of dimensions in the nonlinear optical waveguide in the first portion and the second portion is selected to cause the light to have a phase walk-off that is an odd multiple of 180 degrees.

An optical waveguide structure comprising a nonlinear optical waveguide, a central region, a first side region, and a second side region. The central region is located within the nonlinear optical waveguide, wherein the central region comprises a nonlinear optical material. The first side region is on a first side of the central region and the second side region is on a second side of the central region. The nonlinear optical material comprising the central region has a first nonlinear coefficient that is larger than a second nonlinear coefficient of a second material comprising the first side region and the second side region.

An optical element includes Strontium tetraborate SrB.sub.4O.sub.7 (SBO) crystal plates that are cooperatively configured to create a periodic structure for quasi-phase-matching (QPM) is used in the final frequency converting stage of a laser assembly to generate laser output light having a wavelength in the range of 125 nm to 183 nm. One or more fundamental light beams having fundamental wavelengths between 1 and 1.1 μm are doubled and/or summed using multiple intermediate frequency conversion stages to generate one or more intermediate light beam frequencies (e.g., second through eighth harmonics, or sums thereof), and then the final frequency converting stage utilizes the optical element to either double a single intermediate light beam frequency or to sum two intermediate light beam frequencies to generate the desired laser output light at high power and photon energy levels. A method and inspection system incorporating the laser assembly is also described.

A device for high-speed real-time sampling of mid-infrared ultrafast light signals includes a time domain amplification unit and a detection unit. The time domain amplification unit is used to perform sampling and time domain amplification on signal light incident to the time domain amplification unit, and convert the signal light of a mid-infrared band into a near-infrared/visible band. The detection unit is used to receive and record information of the to-be-detected signal light processed by the time domain amplification unit to realize high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal. The present disclosure can accurately obtain subpicosecond transient characteristics of the light signal, breaks through the capacity limit to the response rate of a traditional photoelectric detector, the bandwidth of the oscilloscope and the like, and is applicable to femtosecond-level mid-infrared ultrafast light signals.

The invention relates to an arrangement and a method for efficient, non-linear light conversion. The object of the present invention of specifying an arrangement for efficient, non-linear light conversion, which simultaneously optimally fulfills the local conversion rate, the interaction scale, and the dispersive properties, is achieved in that the arrangement is provided in the form of a component, which comprises an optical waveguide or an optical fiber with or without cavities, wherein said arrangement consists of fiber cladding substrate or waveguide substrate (IV) with an adapted geometry, which defines the light-guiding properties of the fiber mode with designed dispersion properties (VI), and wherein the waveguide or the core carries a grown, atomically-thin layer of transition metal dichalcogenides in the form of crystallites, wherein this layer completely or partially covers the waveguide or the core.

A nonlinear crystal including stacked Strontium tetraborate SrB.sub.4O.sub.7 (SBO) crystal plates that are cooperatively configured to create a periodic structure for quasi-phase-matching (QPM) is used in the final frequency converting stage of a laser assembly to generate laser output light having a wavelength in the range of 125 nm to 183 nm. One or more fundamental light beams having fundamental wavelengths between 1 and 1.1 μm are doubled and/or summed using multiple intermediate frequency conversion stages to generate one or more intermediate light beam frequencies (e.g., second through eighth harmonics, or sums thereof), and then the final frequency converting stage utilizes the nonlinear crystal to either double a single intermediate light beam frequency or to sum two intermediate light beam frequencies to generate the desired laser output light at high power and photon energy levels. A method and inspection system incorporating the laser assembly is also described.

Techniques for generating an arbitrary target electromagnetic signal with a nonlinear material, include determining a time varying target amplitude and target phase and an order n of a nonlinear material. For each time, a first set of nth roots of the target amplitude and a second set of nth roots of the target phase are determined. An input amplitude based on one value from the first set and an input phase based on one value from the second set is determined at each time. A difference between temporally successive values of phase is minimized. An electromagnetic signal is modulated to impose the input amplitude and phase to produce a modulated electromagnetic input signal that is introduced into the nonlinear material to produce a target electromagnetic signal.