The system and method for a scalable optically pumped CO.sub.2 laser. The optically pumped CO.sub.2 laser having a Tm fiber laser configured to pump a Q-switched Ho laser that is configured to pump a molecular isotopologue mix of CO.sub.2 above atmospheric pressure, to produce a broadband, high energy, tunable output beam.

A hybrid optical amplifier is proposed that includes a preamplifier element formed of single-clad Ho-doped optical fiber and a power amplifier element formed of single-clad Tm-doped (or Tm—Ho co-doped) optical fiber. The preamplifier is used to impart gain to an input signal propagating at a wavelength λ.sub.S in the presence of a first pump beam operating at λ.sub.P1, creating an amplified output over a defined transmission bandwidth. The power amplifier element is disposed at the output of the preamplifier element and provides an additional level of gain to the output of the preamplifier element in the presence of a second pump beam operating at λ.sub.P2. A passband filter may be used between the preamplifier and the power amplifier to ensure that only wavelength components within the defined transmission bandwidth are applied as an output to the power amplifier.

The invention discloses a preparation method and device of active microcrystalline fiber, place the prefabricated rod in the drawing furnace for wire drawing, the drawn fiber is induced by magnetic field in uncoated state and combined with laser treatment technology, the laser beam is focused on the fiber and recrystallized after laser treatment to obtain active microcrystalline fiber. Appropriate laser processing power directly affects the silicate glass fiber in the crystal structure, type, degree of crystallinity, grain size, content, and how much residual phase of glass. Induced by external magnetic field, the thermodynamics and dynamics of crystallization process are changed, make the crystal size distribution is better and uniform, reduce the phenomenon of condensation and makes the grain size is smaller.

Examples of robust self-starting passively mode locked fiber oscillators are described. In certain implementations, the oscillators are configured as Fabry-Perot cavities containing an optical loop mirror on one cavity end and a bulk mirror or saturable absorber on the other end. The loop mirror can be further configured with an adjustable line phase delay to optimize modelocking. All intra-cavity fiber(s) can be polarization maintaining. Dispersion compensation components such as, e.g., dispersion compensation fibers, bulk diffraction gratings or fiber Bragg gratings may be included. The oscillators may include a bandpass filter to obtain high pulse energies when operating in the similariton regime. The oscillator output can be amplified and used whenever high power short pulses are required. For example the oscillators can be configured as frequency comb sources or supercontinuum sources. In conjunction with repetition rate modulation, applications include dual scanning delay lines and trace gas detection.

Ultrashort pulse fiber amplifier having a pulse width from 200 ps to 200 fs comprising a rare earth oxide doped multicomponent glass fibers for laser amplification, including a core and a cladding, the core comprising at least 2 weight percent glass network modifier selected from BaO, CaO, MgO, ZnO, PbO, K.sub.2O, Na.sub.2O, Li.sub.2O, Y.sub.2O.sub.3, or combinations; wherein the mode of the core is guided with step index difference between the core and the cladding, a numerical aperture of the fiber is between 0.01 and 0.04; core diameter is from about 60 microns to about 150 microns, and a length of the gain fiber is shorter than 60 cm.

Low wavelength infrared Super Continuum (SC) signals from a master oscillator seeds an amplifier that supports the Raman effect. Counter-propagating, high-power, continuous wave, and quasi-continuous wave quantum cascade lasers pumps (amplify) the optical seeds forming multiple coherent wavelength optical pump sources.

A laser system may include a laser resonator configured to emit an input laser beam having an elliptical cross-sectional shape. The laser system also may include first reflective device configured to reflect the input laser beam to produce a first reflected laser beam. The first reflective device may include a spherical surface for reflecting the input laser beam. The laser system also may include a second reflective device configured to reflect the first reflected laser beam to produce a second reflected laser beam. The laser system also may include a coupling device configured to focus the second reflected laser beam to produce an output laser beam. The coupling device may include a spherical surface for receiving the second reflected laser beam. The laser system also may include an optic fiber configured to transmit the output laser beam for emission of the output laser beam onto a target area.

A laser system includes a first laser cavity to output a laser light along a first path, a first mirror to receive the laser light from the first laser cavity, and redirect the laser light along a second path that is different than the first path, a second mirror to receive the laser light from the first mirror, and redirect the laser light along a third path that is different than the first path and the second path, a beam splitter located at a first position on the third path, a beam combiner located at a second position on the third path; and a coupling lens assembly, the coupling lens assembly including a lens located at a third position on the third path, wherein the coupling lens assembly moves the lens in x-, y-, and x-directions.

A laser apparatus and a polycrystalline material are described. The apparatus includes the polycrystalline material which is configured to receive pumping light at a pump wavelength and to produce an optical gain for laser oscillation at a laser wavelength different from the pump wavelength. The polycrystalline material includes a ceramic material with a predetermined grain size. The polycrystalline material further includes a rare earth dopant with a predetermined concentration, wherein the predetermined grain size and the predetermined concentration cause the polycrystalline material to exhibit the optical gain at the laser wavelength.

A wavelength-tunable, polarization-maintaining (PM) fiber laser for use in the two micron wavelength region is based upon a ring laser geometry and includes sections of polarization-maintaining (PM) optical fiber for supporting propagation of the circulating laser radiation around the ring. At least one gain module is included in the ring and is formed of polarization-maintaining active optical fiber including a core region that is doped with either Thulium (Tm) or Holmium (Ho), or co-doped with both of these rare earth materials. In the presence of a pump beam operating at a suitable wavelength, the gain module(s) generate laser radiation at a wavelength within the two micron region. A PM-based tunable bandpass filter (BPF) is included within the ring and used to control/adjust the wavelength of the output beam provided by the fiber laser.