A method for generating a single-cavity dualcomb or multicomb for laser spectroscopy, the method comprising the steps of providing a laser system comprising a pump source, a gain medium, and a resonator having a spectral filter; spectrally filtering, by the spectral filter, light in the resonator and attenuating, in particular blocking, by the spectral filter, one or more wavelength bands at least one of which being located completely within the gain bandwidth of the laser system such that two or more at least partially separated spectral regions are provided; mode-locking the two or more at least partially separated spectral regions.

The technology disclosed in this patent document allows mode locking of both selected longitudinal and transverse modes to produce laser pulses. The laser light produced based on such mode locking exhibits a 3-dimensional mode profile based on the locked longitudinal and transverse modes.

One illustrative laser disclosed herein includes a gain medium layer having a first width in a transverse direction that is orthogonal to a laser emitting direction of the laser, and an upper light-confining structure positioned above an upper surface of the gain medium layer, wherein the upper light-confining structure has a second width in the transverse direction that is equal to or less than the first width and comprises at least one material having an index of refraction that is at least 2.0. The laser also includes a lower light-confining structure positioned below a lower surface of the gain medium layer, wherein the lower light-confining structure has a third width in the transverse direction that is equal to or less than the first width and comprises at least one material having an index of refraction that is at least 2.0.

A collinear T-cavity VECSEL system generating intracavity Hermite-Gaussian modes at multiple wavelengths, configured to vary each of these wavelengths individually and independently. A mode converter element and/or an astigmatic mode converter is/are aligned intracavity to reversibly convert the Gaussian modes to HG modes to Laguerre-Gaussian modes, the latter forming the system output having any of the wavelengths provided by the spectrum resulting from nonlinear frequency-mixing intracavity (including generation of UV, visible, mid-IR light). The laser system delivers Watt-level output power in tunable high-order transverse mode distribution.

A laser device for laser resonance ionization includes a wavelength variable grating-type titanium-doped sapphire laser and includes a titanium (Ti) doped titanium sapphire crystal disposed within a resonator. The titanium sapphire crystal is fixedly disposed on a stage. The titanium-doped sapphire crystal can be moved in the optical axis direction by the stage, thereby changing the position of the titanium-doped sapphire crystal. The switching between the wideband mode and the high-output mode can be performed by changing the position of the titanium-doped sapphire crystal.

The present disclosure relates more to mode mixing optical fibers useful, for example in providing optical fiber laser outputs having a desired beam product parameter and beam profile. In one aspect, the disclosure provides a mode mixing optical fiber for delivering optical radiation having a wavelength, the mode mixing optical fiber having an input end, an output end, a centerline and a refractive index profile, the mode mixing optical fiber comprising: an innermost core, the innermost core having a refractive index profile; and a cladding disposed about the innermost core, wherein the mode mixing optical fiber has at least five modes at the wavelength, and wherein the mode mixing optical fiber is configured to distribute a fraction of the light input at its input end from its lower-order modes to its higher-order modes.

The present invention discloses a transverse mode switchable all-fiber high-order mode Brillouin laser. The laser comprises a narrow linewidth pump laser, an optical amplifier, a 1N optical switch (N2), a fiber mode selection coupler group, a first polarization controller, a fiber circulator, a fiber coupler, a second polarization controller, and a few-mode fiber. Based on the Brillouin nonlinear gain of a few-mode fiber in a ring cavity, the present invention realizes the resonance amplification of a specific order transverse mode in the cavity, and obtains the transverse mode switchable high-order mode laser beam output. The present invention, adopting an all-fiber structure, has the advantages of simple structure, low cost, easy fiber system integration, high stability and narrow linewidth of outputted laser beams, etc., and improves the practicality and reliability of high-order mode lasers.

The present invention discloses a transverse mode switchable all-fiber high-order mode Brillouin laser. The laser comprises a narrow linewidth pump laser, an optical amplifier, a 1N optical switch (N2), a fiber mode selection coupler group, a first polarization controller, a fiber circulator, a fiber coupler, a second polarization controller, and a few-mode fiber. Based on the Brillouin nonlinear gain of a few-mode fiber in a ring cavity, the present invention realizes the resonance amplification of a specific order transverse mode in the cavity, and obtains the transverse mode switchable high-order mode laser beam output. The present invention, adopting an all-fiber structure, has the advantages of simple structure, low cost, easy fiber system integration, high stability and narrow linewidth of outputted laser beams, etc., and improves the practicality and reliability of high-order mode lasers.

Fine-structure in the transverse mode of an excimer laser beam is minimized by having a plurality of resonator mirrors located at each end of a linear excimer laser. At one end, a highly-reflective end mirror and a partially-reflective end mirror are inclined at small angle with respect to each other. At the other end, two output-coupling mirrors are inclined at a small angle with respect to each other. This arrangement of resonator mirrors generates a composite laser beam that blurs any fine structure.

The present disclosure relates more to mode mixing optical fibers useful, for example in providing optical fiber laser outputs having a desired beam product parameter and beam profile. In one aspect, the disclosure provides a mode mixing optical fiber for delivering optical radiation having a wavelength, the mode mixing optical fiber having an input end, an output end, a centerline and a refractive index profile, the mode mixing optical fiber comprising: an innermost core, the innermost core having a refractive index profile; and a cladding disposed about the innermost core, wherein the mode mixing optical fiber has at least five modes at the wavelength, and wherein the mode mixing optical fiber is configured to distribute a fraction of the light input at its input end from its lower-order modes to its higher-order modes.