Publications

The objective of SET-170 was to advance the state-of-the-art in mid-IR fiber lasers, to support development of active sources primarily for countermeasures and remote sensing applications. The Task Group made significant advances in each of the three areas of its program of work. (1) In direct-lasing fibers, we identified trivalent holmium operating ~ 3.9 µm as the active ion most likely to result in a successful laser; and fluoroindate fiber as the most promising host material. Spectroscopic analysis and modelling were used to evaluate feasibility and to calculate fiber specifications, and led to demonstration of lasing in a sample of Ho-doped glass. (2) Supercontinuum work focused on increasing output power and especially extending the output spectrum and improving efficiency at longer wavelengths. Results include power scaling demonstrations in fluoride and chalcogenide fibers; demonstration of efficient power distribution at wavelengths longer than 3 µm; and a comparison of different fiber-based pumping techniques. (3) As an intermediate step to all-fiber mid-IR sources, SET-170 considered how best to use fiber lasers to pump bulk non-linear (χ(2)) devices. Pumping strategies were investigated and demonstrated for ZGP, PPLN, and OPGaAs, representing the current spectrum of birefringent, poled ferroelectric, and orientation-patterned non-linear materials.

The objective of SET-170 was to advance the state-of-the-art in mid-IR fiber lasers, to support development of active sources primarily for countermeasures and remote sensing applications. The Task Group made significant advances in each of the three areas of its program of work. (1) In direct-lasing fibers, we identified trivalent holmium operating ~ 3.9 µm as the active ion most likely to result in a successful laser; and fluoroindate fiber as the most promising host material. Spectroscopic analysis and modelling were used to evaluate feasibility and to calculate fiber specifications, and led to demonstration of lasing in a sample of Ho-doped glass. (2) Supercontinuum work focused on increasing output power and especially extending the output spectrum and improving efficiency at longer wavelengths. Results include power scaling demonstrations in fluoride and chalcogenide fibers; demonstration of efficient power distribution at wavelengths longer than 3 µm; and a comparison of different fiber-based pumping techniques. (3) As an intermediate step to all-fiber mid-IR sources, SET-170 considered how best to use fiber lasers to pump bulk non-linear (χ(2)) devices. Pumping strategies were investigated and demonstrated for ZGP, PPLN, and OPGaAs, representing the current spectrum of birefringent, poled ferroelectric, and orientation-patterned non-linear materials.

Multiple

Fiber lasers;Fiber materials ;Fiber optics;Fluoride fiber;Fluoride glass;Guided wave sources;Infrared spectroscopy;Laser materials;Laser modelling;Laser spectroscopy;Lasers;Mid-infrared;Non-linear frequency conversion;Non-linear optics;Optical parametric processes;Optical resonators;Rare earth lasers;Supercontinuum generation

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