A light source for an imaging system. The light source includes a microresonator laser array having opposing mirrors arranged substantially parallel to one another. A laser gain medium is between the opposing mirrors. An array of microrefractive elements is arranged to stabilize the microresonator. A pump laser's output is shaped by a lens that directs it toward the micro-resonator laser array. An output lens directs a plurality of laser beams from the microresonator laser array to be incoherently combined at an object to be illuminated.

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 higher-order-mode (HOM) fiber of a fiber laser has step index and guidance diameter (GD) defining wavelength-dependent dispersion characteristics and effective areas for corresponding HOMS of optical signal propagation. One HOM has anomalous dispersion and effective area defining a first wavelength and first power of a pulse optical signal for conversion to a second wavelength and second power by soliton self-frequency shifting (SSFS). By controlling step index and GD, the dispersion and effective area of a HOM are adjusted to bring the second wavelength into a desired range, enabling applications requiring non-conventional fiber laser wavelengths. HOMS may share a predetermined group index and group velocity at wavelengths established by a Raman gain peak to effect wavelength conversion by interpulse and intermodal Raman scattering, which may occur in a cascaded fashion to yield multicolor lasers with desired wavelengths, pulse energies and pulse widths.

A fiber laser device includes a pumping light source, an amplifying fiber, an input side fiber fusion-spliced on an input side of the amplifying fiber and formed with a HR-FBG, an output side fiber fusion-spliced on an output side of the amplifying fiber and formed with an OC-FBG having a reflectivity smaller than that of the HR-FBG, an output end, and a mode filter, wherein the input side fiber or an intermediate fiber disposed between the amplifying fiber and the input side fiber is fusion-spliced with the amplifying fiber via a fusion splice portion, and at least a portion of the mode filter is disposed in a region between the fusion splice portion and a position separated from the fusion splice portion by a coherence length of beating caused by mode interference of signal light propagating in the amplifying fiber.

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 unit may include a laser chamber including a pair of discharge electrodes that are opposed to each other in a first direction with an electrode gap interposed in between and are configured to provide a discharge width in a second direction, orthogonal to the first direction, smaller than the electrode gap; and an optical resonator including a first optical member and a second optical member that are opposed to each other in a third direction orthogonal to both the first direction and the second direction with the discharge electrodes interposed in between, and configured to amplify laser light generated between the discharge electrodes and output amplified laser light, the optical resonator satisfying the following expression to configure a stable resonator in the second direction:
0<G1.Math.G2<1 where G1 is a G parameter of the first optical member, and G2 is a G parameter of the second optical member.

An optical fiber, used in a laser device, propagates light having a wavelength of 1060 nm through a core in at least an LP01 mode and an LP11 mode. A difference between a propagation constant of light in the LP01 mode and a propagation constant of light in the LP11 mode is 1850 rad/m or more and 4000 rad/m or less.

A method of inducing light losses at a parasitic wavelength in a fiber laser system includes providing a wavelength discriminator (WD) spaced from and between feeding and process fibers or from the end output of the feeding fiber so as to induce losses of light at parasitic wavelength. The device implementing the disclosed method is configured with a laser source, the delivery fiber and WD spaced at a distance between the surface to be treated and the end of the delivery fiber, wherein the WD receives the parasitic light over free space and is configured as a dichroic filter inducing losses to the light at the parasitic wavelength.

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.

Systems and methods are provided for imaging using complex lasers. In general, a complex laser may be used as an electromagnetic source for an imaging application. The use of a lower spatial coherence configured complex laser in imaging applications may advantageously mitigate coherent artifacts in imaging such as cross-talk and speckle and improve overall image quality. Imaging applications where a complex laser may be useful include both incoherent imaging applications, such as digital light projectors and traditional microscopy, and coherent imaging applications, such as optical coherence tomography (OCT) and holography. The systems and methods provided also enable controlling the degree of spatial coherence of a complex laser.