A laser system may include one or more seed lasers to generate a pulsed seed beam including one or more laser pulses, a pulse pattern generator to generate an intermediate patterned burst-mode beam from at least one laser pulse from the pulsed seed beam, where the pulse pattern generator includes splits the at least one laser pulse from the pulsed seed beam along two or more delay paths and combines light along the two or more delay paths to a common optical path, and where the intermediate patterned burst-mode beam includes laser pulses with a selected pattern of inter-pulse spacings associated with the two or more delay paths. The laser system may further include power amplifiers to amplify the intermediate patterned burst-mode beam to form an amplified patterned burst-mode beam, where the amplified patterned burst-mode beam includes amplified laser pulses with the selected pattern of inter-pulse spacings.

An amplified optical link having a fault-protection capability that is based, at least in part, on the ability to selectively and independently power up and down different groups of optical amplifiers within the link. In an example embodiment, the optical link is implemented using an optical fiber cable having an electrical power line and arrays of optical amplifiers connected between successive optical fiber segments to form a plurality of disjoint groups of parallel optical paths between the ends of the optical fiber cable. The electrical power line is operable to selectively power, as a group, the optical amplifiers of at least some of the disjoint groups. In various embodiments, different optical paths can be implemented using different respective strands of a single-core optical fiber, different respective cores of a multi-core optical fiber, and/or different respective sets of spatial modes of a multimode optical fiber.

A pulse width expansion apparatus according to an aspect of the present disclosure includes a polarization beam splitter and a transfer optical system. The transfer optical system includes ¼-wavelength and reflection mirror pairs. The ¼-wavelength mirror pair include first and second ¼-wavelength mirrors. The first ¼-wavelength mirror provides ¼-wavelength phase shift and reflects a pulse laser beam. The second ¼-wavelength mirror provides ¼-wavelength phase shift and reflects the pulse laser beam reflected by the first ¼-wavelength mirror. The reflection mirror pair are disposed on an optical path before and after or between the ¼-wavelength mirror pair. The transfer optical system transfers an image of an input pulse laser beam on the polarization beam splitter to the optical path between the ¼-wavelength mirror pair at one-to-one magnification as a first transfer image and transfers the first transfer image to the polarization beam splitter at one-to-one magnification as a second transfer image.

A photonic device is configured with a photonic integrated circuit (PIC), a plurality of fiber-based gain mediums in optical communication with the PIC, and at least one optical pump outputting pump light coupled into two or more gain mediums. At least one of the fiber-based gain media and the PIC form a hybrid resonant optical cavity there between operative to lase light into the PIC. The gain media further include one or more fiber amplifiers amplifying light signals coupled into and decoupled from the PIC. The photonic device is integrated with Si photonic passive and active photonic elements, while ail fiber links between the gain media and PIC are free from these elements.

A photonic device is configured with a photonic integrated circuit (PIC), a plurality of fiber-based gain mediums in optical communication with the PIC, and at least one optical pump outputting pump light coupled into two or more gain mediums. At least one of the fiber-based gain media and the PIC form a hybrid resonant optical cavity there between operative to lase light into the PIC. The gain media further include one or more fiber amplifiers amplifying light signals coupled into and decoupled from the PIC. The photonic device is integrated with Si photonic passive and active photonic elements, while ail fiber links between the gain media and PIC are free from these elements.

A laser device includes: a laser unit that outputs laser light; an output end that launches the laser light; a first fusion splice portion; and a second fusion splice portion. In each of the first fusion splice portion and the second fusion splice portion, two multi-mode fibers are fusion-spliced. Each of the two multi-mode fibers include a core through which the laser light propagates and a cladding that surrounds the core. The first fusion splice portion is disposed closer to the laser unit than is the second fusion splice portion. At least a part of the core in the first fusion splice portion contains a dopant that is the same type as a dopant contained in the cladding in the first fusion splice portion for decreasing a refractive index.

In various embodiments, a beam-parameter adjustment system and focusing system alters a spatial power distribution of a radiation beams before the beam is coupled into an optical fiber or delivered to a workpiece.

In various embodiments, a beam-parameter adjustment system and focusing system alters a spatial power distribution of a radiation beams before the beam is coupled into an optical fiber or delivered to a workpiece.

A method for generating gigahertz bursts of laser pulses is provided, where: 1) time delay T2 of the delayed part with respect to the undelayed part of the input pulse is longer than a time period T1 between said input pulse and the next input pulse; 2) the bursts of output pulses have an incrementally increasing number of pulses; 3) intra-burst pulse separation inside the formed bursts is equal to T3=T2−T1 and corresponds to an ultra-high pulse repetition rate higher than 100 MHz. In another embodiment: 1) T2 is longer than M*T1, where M=2, 3, etc.; 2) output train of bursts is composed of bursts of pulses wherein M adjacent bursts have identical number of pulses; 3) T3 is equal to T3=T2−M*T1. The laser apparatus for implementing the method is provided.

The invention relates to a laser beam device for generating an effective laser beam and an illuminating laser beam, having a coupling element for coupling the illuminating laser beam into a beam path of the effective laser beam. The laser beam device is characterized in that the coupling element has a first sub-region and a second sub-region that is different from the first sub-region, and the effective laser beam, the illuminating laser beam and the coupling element are arranged relative to one another such that the effective laser beam is directed onto the first sub-region and the illuminating laser beam is directed onto the second sub-region, the first sub-region being transparent to the effective laser beam and the second sub-region being designed to reflect the illuminating laser beam in parallel with the effective laser beam.