Abstract: Method for fabricating of all-optical-fiber based optical polarizer devoid of fusing of first and second optical fibers. The method includes a process of forming a substantially adiabatic optical fiber taper by pulling an optical fiber and interrupting this process when an optical power parameter measured at an output of the optical fiber is reduced below a pre-defined threshold as a result of said pulling. An optically-tapered single-mode polarization-maintaining optical fiber element fabricated according to the method and configured as such all-optical-fiber polarizer.

Abstract: Method for fabricating of all-optical-fiber based optical polarizer devoid of fusing of first and second optical fibers. The method includes a process of forming a substantially adiabatic optical fiber taper by pulling an optical fiber and interrupting this process when an optical power parameter measured at an output of the optical fiber is reduced below a pre-defined threshold as a result of said pulling. An optically-tapered single-mode polarization-maintaining optical fiber element fabricated according to the method and configured as such all-optical-fiber polarizer.

Abstract: Method and system for a laser welding process employing the use of a single pulsed fiber laser source configured to generate a radiative output with a wavelength spectrum extending from about 1.8 microns to about 2.6 microns. In a specific case, the laser output from the single pulsed fiber laser source is focused onto the interface of the two pieces of materials at least one of which includes any of glasses, inorganic crystals, and semiconductors.

Abstract: A method for fabricating an optical fiber coupler device includes a step of tangibly fusing a first outer cladding of a first optical fiber with a second outer cladding of a second optical fiber as a result of pulling and heating the first and second optical fibers at lengths not exceeding 3 mm to form a first region of structurally-integrated with one another first and second optical fibers, and a step of heating a second, neighboring region of these fibers to configure the device to transmit optical power of at least about a hundred Watts and up to at least a kWatt from the input end to the output end with a value of throughput loss not exceeding 0.2 dB.

Abstract: Method and system for a laser welding process employing the use of a single pulsed fiber laser source configured to generate a radiative output with a wavelength spectrum extending from about 1.8 microns to about 2.6 microns. In a specific case, the laser output from the single pulsed fiber laser source is focused onto the interface of the two pieces of materials at least one of which includes any of glasses, inorganic crystals, and semiconductors.

Abstract: A laser material processing system which includes a pulsed fiber laser source having a continuous wavelength bandwidth of larger than 100 nm and pulse width of from 100 femtosecond to 1 microsecond, a broad band laser emitted from one core of an optical fiber, where the broad band laser is applied to a subject material to produce removal of the subject material and/or color change of the subject material.

Abstract: A laser material processing system which includes a pulsed fiber laser source having a continuous wavelength bandwidth of larger than 100 nm and pulse width of from 100 femtosecond to 1 microsecond, a broad band laser emitted from one core of an optical fiber, where the broad band laser is applied to a subject material to produce removal of the subject material and/or color change of the subject material.

Abstract: A method of ablating a solid substance within a mammalian body is presented. The method includes generating a superheated zone within the body using a fiber lasing assembly that emits pulses at a pulse repetition rate of 1 kHz to 500 kHz, where each pulse has a wavelength from 1.7 micron to 2.2 micron, a pulse width from 2 ns to 800 ns, and a pulse energy from 0.05 mJ to 2 mJ. The fiber lasing assembly used further includes a seed laser and an amplifier optically connected to the seed laser by an Ho-doped, Tm-doped, or Ho Tm co-doped fiber.

Abstract: An all-fiber optic Faraday rotator and isolator is presented. The device has a multicomponent glass optical fiber having a core having a first doping concentration of 55%-85% (wt./wt.) of a first rare-earth oxide and a cladding having a section doping concentration of 55%-85% (wt./wt.) of a second rare-earth oxide, where the first rare-earth oxide and the second rare earth oxide are one or more of Pr2O3, Nd2O3, Pm2O3, Sm2O3, Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3, Yb2O3, La2O3, Ga2O3, Ce2O3, and Lu2O3, and where the refractive index of the cladding is lower than a refractive index of the core. The fiber optic device further includes multiple magnetic cells each formed to include a bore extending there through, where the fiber is disposed in the bore of one of the magnetic cells.

Abstract: A mode-locked fiber laser comprising a multicomponent glass fiber doped with a trivalent rare-earth ion of thulium and/or holmium and including a fiber-optic based passive saturable absorber that contains an adhesive material mixed with a saturable absorbing components and is disposed along the length of an optical fiber such as to assure that a mode propagating within the fiber spatially overlaps with the volume occupied by the saturable absorbing components.

Abstract: An all-fiber Faraday rotator including a plurality of optical fibers doped, at unusually high concentrations of at least several tens of percent, with rare-earth oxides, an all-optical-fiber optical isolator employing a polarization-maintaining fiber-optic splitter, and a method of optically-isolating a laser source from unwanted feedback with such an optical isolator. In a case where the doping concentration exceeds 55 weight-%, the length of the Faraday rotator achieving a 45-degree rotation of the polarization vector of light guided by an optical fiber does not exceed approximately 10 cm.

Abstract: A mode-locked fiber laser comprising a multicomponent glass fiber doped with a trivalent rare-earth ion of thulium and/or holmium and including a fiber-optic based passive saturable absorber that contains an adhesive material mixed with a saturable absorbing components and is disposed along the length of an optical fiber such as to assure that a mode propagating within the fiber spatially overlaps with the volume occupied by the saturable absorbing components.

Abstract: A mode-locked fiber laser comprising a multicomponent glass fiber doped with a trivalent rare-earth ion of thulium and/or holmium.

Abstract: A mode-locked fiber laser comprising a multicomponent glass fiber doped with a trivalent rare-earth ion of thulium and/or holmium.

Abstract: A 2-?m fiber Amplified Spontaneous Emission (ASE) source provides a wide emission bandwidth and improved spectral stability/purity for a given output power. The fiber ASE source is formed from a heavy metal oxide multicomponent glass selected from germanate, tellurite and bismuth oxides and doped with high concentrations, 0.5-15 wt. %, thulium oxides (Tm2O3) or 0.1-5 wt% holmium oxides (Ho2O3) or mixtures thereof. The high concentration of thulium dopants provide highly efficient pump absorption and high quantum efficiency. Co-doping of Tm and Ho can broaden the ASE spectrum.

Abstract: A distributed fiber sensor based on spontaneous Brillouin scattering uses a single-frequency fiber laser as a source and a cw Brillouin fiber ring laser as an OLO to optically shift the frequency of the OLO to set the Brillouin/OLO beat frequency within the bandwidth of a conventional heterodyne receiver. The distributed fiber sensor is capable of real-time measurement of both temperature and strain.

Abstract: A single-frequency Brillouin fiber ring laser with extremely narrow linewidth comprises a single-frequency narrow-linewidth rapid-tunable pump laser, a temperature-controlled acoustically-damped package for Brillouin fiber ring laser cavity, and an auto-tracking feedback electronic loop with novel configuration for active stabilization. The Pound-Drever-Hall frequency-locking technique is employed to keep pump laser frequency in resonance with one of the Brillouin fiber ring cavity modes. Instead of changing cavity length of Brillouin fiber ring laser, the pump laser frequency is rapidly tuned in the auto-tracking feedback electronic loop. This enables extremely narrow linewidth radiation emitted from a Brillouin fiber ring laser without stretching the fiber ring.

Abstract: An all-fiber Q-switched laser includes a gain fiber spliced between narrowband and broadband fiber gratings that define a polarization-dependent resonant cavity. The narrowband grating is, for example, formed in a PM fiber to create a polarization-dependent reflection band. A modulator applies stress to the fiber chain to induce birefringence and switch the cavity Q-factor to alternately store energy in the gain fiber and then release the energy in a laser pulse.

Abstract: A short laser cavity (up to 30 cm in length) comprising a free-space tunable MEMS Fabry-Perot filter, a collimating lens and a section of erbium-doped phosphate gain fiber (2-25 cm) is formed between a pair of broadband reflectors. The cavity is optically pumped to excite the erbium ions and provide gain, which establishes an initial longitudinal mode structure that spans the C-band with a mode spacing of at least 0.3 GHz and a roundtrip unsaturated gain of at least 8 dB over the tuning range. A controller tunes the MEMS filter, which has a filter function whose spectral width is at most ten and preferably less than four times the longitudinal mode spacing, to align its transmission maxima to one of a plurality of discrete output wavelengths that span the C-band. A thermal control element adjusts the longitudinal mode structure to align a single mode with the transmission maxima of the filter.

Abstract: A narrow-linewidth high-power single-frequency laser is realized by pumping a laser cavity with a pair of polarized single-mode pump lasers that are driven below their respective “micro-kink” regions and combined with a polarized beam combiner. The pump lasers emit at the same wavelength and include a length of polarization-maintaining (PM) fiber to maintain the polarization of the respective pumps. The laser cavity is selected from microchip, fiber and waveguide devices and is provided with optical feedback. This laser is capable of producing a stable high-power single-mode signal with a very narrow linewidth, e.g. less than 10 kHz and preferably less than 3 kHz.