A single mode fiber pulsed oscillator includes an all normal dispersion ring cavity provided with a mode-locking fiber loop component and a giant chirp generating fiber component. The mode-locking fiber loop component is configured with a hybrid of NOLM and NALM configurations which is operative to induce a first phase acquisition of a spectrally narrow pulse due to SPM. The giant chirp generating fiber loop component is configured to induce the additional phase acquisition to the pulse broadened in the mode-locking fiber component so as to generate a pulse with a giant chirp. The fiber loop components each include a fiber amplifier and a coil of fiber. The amplifiers each are configured with an active fiber provided with a core which supports multiple transverse mode in a range of wavelength except for the desired wavelength at which the core is configured to support a single fundamental mode.

An optical fiber for a fiber laser includes a core to which a rare-earth element is added, a first cladding formed around the core; and a second cladding formed around the first cladding, and excitation light is guided from at least one end of the first cladding to excite the rare-earth element to output a laser oscillation light. An addition concentration of the rare-earth element to the core is different in a longitudinal direction of the optical fiber for a fiber laser, and a core diameter and a numerical aperture of the optical fiber for a fiber laser are constant in the longitudinal direction of the optical fiber for a fiber laser.

A laser amplifier includes a broadband laser gain medium having a first lateral face spaced from an opposing second lateral face at a wedge angle with respect to the first lateral face. At least the first lateral face receives a pump beam and one of the first and second lateral faces receives a seed beam. A first coating on the first lateral face is highly transmissive at the pump beam wavelength. A second coating is disposed on the second lateral face. In one example, the first coating is highly reflective at the seed beam wavelength over a first wavelength band and the second coating is highly reflective at the seed beam wavelength over a second wavelength band (partially or fully) overlapping the first wavelength band.

The invention relates to phosphate-based glasses suitable for use as a solid laser medium, doped with Er3+ and sensitized with Yb, in “eye-safe” applications. In particular, the invention relates to improving the physical properties of such phosphate-based laser glass composition, particularly with regards to strength of the glass structure and improved thermal shock resistance.

An active element added-optical fiber includes a core, having a radius d and including a first region and a second region, and a cladding that surrounds an outer peripheral surface of the core without a gap and propagates light in a few mode. The first region is a region from a central axis of the core to a radius ra and contains ytterbium as an active element. The second region is a region to the radius d that surrounds the first region without a gap and contains a plurality of dopants, one of which is germanium. The active element is not added to a region within the second region from a radius rc to the radius d. The germanium is not added to a region within the first region from the central axis to a radius rb, and a concentration of the germanium is highest among the plurality of dopants.

A laser system for generating optical pulses at an operating wavelength of the laser system. The system has an optical resonator comprising first and second reflectors, and a tapered optical fiber disposed between the first and second reflectors. The tapered optical fiber has a core which has a tapered input section which tapers from single mode to multimode at the laser operating wavelength, an inner section of substantially constant diameter capable of supporting multiple modes at the laser operating wavelength and a tapered output section which tapers from a first diameter to a second diameter that is smaller than the first diameter.

Double-clad optical fibers with polymer outer coatings are used in fiber amplifiers and fiber lasers to guide and amplify light. As the optical power increases, the optical fibers must dissipate more heat. Unfortunately, it is difficult to dissipate heat through a polymer cladding, especially at high altitude, without introducing phase noise in the optical signal. To overcome this problem, the inventors have realized metallized polymer-clad optical fibers with superior heat dissipation characteristics than conventional polymer-clad optical fibers. An example metallized polymer-clad optical fiber includes a thin chrome layer that is vacuum-deposited onto the polymer cladding at low temperature, then electroplated with a thicker copper layer. In operation, the copper layer dissipates heat from within the fiber's core and claddings via a heatsink, enabling the fiber to guide and amplify high-power optical signals at high altitude.

A femtosecond laser based laser processing system having a femtosecond laser, frequency conversion optics, beam manipulation optics, target motion control, processing chamber, diagnostic systems and system control modules. The femtosecond laser based laser processing system allows for the utilization of the unique heat control in micromachining, and the system has greater output beam stability, continuously variable repetition rate and unique temporal beam shaping capabilities.

A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Peak power handling capability of fiber amplifiers is expanded by using optimized pulse shapes, as well as dispersively broadened pulses. Dispersive pulse stretching in the presence of self-phase modulation and gain results in the formation of high-power parabolic pulses. To ensure a wide tunability of the whole system, Raman-shifting of the compact sources of ultrashort pulses in conjunction with frequency-conversion in nonlinear optical crystals can be implemented, or an Anti-Stokes fiber in conjunction with fiber amplifiers and Raman-shifters are used. Positive dispersion optical amplifiers are used to improve transmission characteristics. An optical communication system utilizes a Raman amplifier fiber pumped by a train of Raman-shifted, wavelength-tunable pump pulses, to thereby amplify an optical signal which counterpropagates within the Raman amplifier fiber with respect to the pump pulses.

A light amplifier according to an aspect of the present invention includes: a seed light source configured to generate a pulsing seed light; an excitation light source configured to generate excitation light; a light amplifying fiber configured to amplify the seed light by the excitation light and output the amplified light; and a control unit configured to control the seed light source and the excitation light source. The control unit has a mode to control the excitation light's power such that as a set value of a pulse width of the amplified light increases, the amplified light's peak energy increases within a threshold value at a minimum set value of the pulse width.