A hybrid fiber rod includes a fiber core and inner and outer cladding layers. The core is doped with an active element. The inner cladding layer surrounds the core, and has a refractive index substantially equal to that of the core. The outer cladding layer surrounds the inner cladding layer, and has a refractive index less than that of the core and inner cladding layer. The core length is about 30 to 2000 times the core diameter. A hybrid fiber rod laser system includes an oscillator laser, modulating device, the rod, and pump laser diode(s) energizing the rod from opposite ends. The rod acts as a waveguide for pump radiation but allows for free-space propagation of laser radiation. The rod may be used in a laser resonator. The core length is less than about twice the Rayleigh range. Degradation from single-mode to multi-mode beam propagation is thus avoided.

A MOPA laser system that includes a seed laser configured to output pulsed laser light, an amplifier configured to receive and amplify the pulsed laser light emitted by the seed laser; and a pump laser configured to deliver a pump laser beam to both the seed laser and the amplifier.

A hybrid fiber rod includes a fiber core and inner and outer cladding layers. The core is doped with an active element. The inner cladding layer surrounds the core, and has a refractive index substantially equal to that of the core. The outer cladding layer surrounds the inner cladding layer, and has a refractive index less than that of the core and inner cladding layer. The core length is about 30 to 2000 times the core diameter. A hybrid fiber rod laser system includes an oscillator laser, modulating device, the rod, and pump laser diode(s) energizing the rod from opposite ends. The rod acts as a waveguide for pump radiation but allows for free-space propagation of laser radiation. The rod may be used in a laser resonator. The core length is less than about twice the Rayleigh range. Degradation from single-mode to multi-mode beam propagation is thus avoided.

The present application discloses various embodiments of a laser amplifier system utilizing multiple end pump spots to pump an optical crystal during the amplification process which includes a telecentric telescope configured to magnify each individual pump beamlet and output the magnified pump beamlets such that the pump beamlets remain parallel and substantially non-divergent incident on an optical crystal positioned within a resonator-like thereby permitting the construction of a compact laser amplifier system.

Core-cladding planar waveguide (PWG) structures and methods of making and using same. The core-cladding PWG structures can be synthesized by hydride vapor phase epitaxy and processed by mechanical and chemical-mechanical polishing. An Er doping concentration of [Er] between 110.sup.18 atoms/cm.sup.3 and 110.sup.22 atoms/cm.sup.3 can be in the core layer. Such PWGs have a core region that can achieve optical confinement between 96% and 99% and above.

In one aspect, a transparent ceramic optic includes: a lasing region comprising at least one lasing species dopant; and a transparent region transparent to light generated by the lasing species. At least the transparent region is doped with at least one other dopant species such that the lasing region and the transparent region are characterized by a difference in refractive index between the two regions in an amount of about 1.010.sup.4 or less.

In one aspect, a system for forming a transparent ceramic optic includes an apparatus configured to deposit a plurality of layers of at least one optic precursor ink to form a monolith using a technique selected from: direct ink writing (DIW) and extrusion freeform fabrication. In another aspect, a system for forming a transparent ceramic optic includes an apparatus configured to deposit a plurality of layers of at least one optic precursor ink to form a monolith using a technique selected from: direct ink writing (DIW) and extrusion freeform fabrication. The apparatus includes a mixing nozzle, wherein the apparatus is configured to create a compositional gradient as a function of nozzle position and flow of two or more inks into the mixing nozzle.