In order to solve the problem that the power consumption of optical amplifiers is not optimized over the life time of a network whose capacity in use varies, an optical amplifier according to an exemplary aspect of the invention includes a gain medium for amplifying a plurality of optical channels, the gain medium including a plurality of cores through which the plurality of optical channels to propagate respectively and a cladding area surrounding the plurality of cores; monitoring means for monitoring the plurality of optical channels inputted into the gain medium and producing a monitoring result; a first light source configured to emit a first light beam to excite the cladding area; a second light source configured to emit a plurality of second light beams to excite each of the plurality of cores individually; and controlling means for making a decision as to whether each of the plurality of cores to transmit one of the plurality of optical channels based on the monitoring result, and controlling the first light source and the second light source based on the decision.

The invention relates to an optical waveguide with at least one core region (1) extending along the longitudinal extent of the optical waveguide, and with a first jacket (2) which, viewed in the cross section of the optical waveguide, surrounds the core region (1). The invention further relates to an optical arrangement with such an optical waveguide, and to a method for producing the optical waveguide. The object of the invention is to make available an optical waveguide for high-performance operation, which is improved in relation to the prior art in terms of mode instability. The invention achieves this object by virtue of the fact that the optical waveguide consists of crystalline material at least in the core region (1).

The present invention discloses a high-peak-power single-frequency narrow-linewidth nanosecond fiber laser based on a triangular pulse, wherein the laser includes: pulsed laser generated by the laser seed injecting into a first power pre-amplifier through a first isolator, and then injecting into a second pre-amplifier and then injecting into a power amplifier; wherein triangle-shaped pulsed laser with fast rising edge is obtained by using electro-optic and acousto-optic modulator to modulate continuous wave single-frequency laser or a single-frequency semiconductor laser directly modulated by radio frequency signal; single-frequency triangle-shaped pulsed laser is employed as the laser source according to the characteristics of narrow intrinsic linewidth and suppression of linewidth broadening caused by SPM, and the power of pulsed laser is amplified through the MOPA system.

The present disclosure relates to a fiber encapsulation mechanism for energy dissipation in a fiber amplifying system. One example embodiment includes an optical fiber amplifier. The optical fiber amplifier includes an optical fiber that includes a gain medium, as well as a polymer layer that at least partially surrounds the optical fiber. The polymer layer is optically transparent. In addition, the optical fiber amplifier includes a pump source. Optical pumping by the pump source amplifies optical signals in the optical fiber and generates excess heat and excess photons. The optical fiber amplifier additionally includes a heatsink layer disposed adjacent to the polymer layer. The heatsink layer conducts the excess heat away from the optical fiber. Further, the optical fiber amplifier includes an optically transparent layer disposed adjacent to the polymer layer. The optically transparent layer transmits the excess photons away from the optical fiber.

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.

Rare earth doped fiber lasers can be robust and efficient sources of high quality light, but are usually limited to the highest gain transitions of the active species. But rare earths typically possess a multitude of potentially useful transitions that might be accessed if the dominant transition can be suppressed. In fiber lasers this suppression is complicated by the very high net gain the dominant transitions exhibit; effective suppression requires some mechanism distributed along the length of the fiber. We have developed a novel waveguide with resonant leakage elements that frustrate guidance at well-defined and selectable wavelengths. Based on this waveguide, we have fabricated a Large Mode Area Neodymium doped fiber with suppression of the four-level transition around 1060 nm, and demonstrated lasing on the three-level transition at 930 nm with good efficiency.

An Nd.sup.3+ optical fiber laser and amplifier operating in the wavelength range from 1300 to 1450 nm is described. The fiber includes a rare earth doped optical amplifier or laser operating within this wavelength band is based upon an optical fiber that guides light in this wavelength band. The waveguide structure attenuates light in the wavelength range from 850 nm to 950 nm and from 1050 nm to 1150 nm.

A white light spectroscopy system includes a super continuum light source having an input light source including semiconductor diodes to generate an input beam having a wavelength shorter than 2.5 microns. The light source includes a cladding-pumped fiber optical amplifier to receive the input beam, and a photonic crystal fiber to receive the amplified optical beam to broaden the spectral width to 100 nm or more forming an output beam in the visible wavelength range. The output beam is pulsed with a repetition rate of 1 Megahertz or higher. The system also includes a lens and/or mirror to receive the output beam, to send the output beam to a scanning stage, and to deliver the received output beam to a sample. A detection system includes dispersive optics and narrow band filters followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.

An optical fiber securing structure includes: an optical fiber including a coating, and a coating-removed section in which a partial section of the coating is removed from the optical fiber; a reinforcement member including main surfaces and a groove formed from one of the main surfaces toward an inside of the reinforcement member, where the groove has a pair of side walls and a bottom wall; and a resin member that secures the coating-removed section to the pair of side walls and the bottom wall. A bottom part of the groove that includes the bottom wall has a widthwise cross-sectional shape where the bottom wall constitutes a trapezoidal shape such that a distance between the pair of side walls becomes greater in a direction away from the bottom wall.

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.