Examples of the present invention include integrated erbium-doped waveguide lasers designed for silicon photonic systems. In some examples, these lasers include laser cavities defined by distributed Bragg reflectors (DBRs) formed in silicon nitride-based waveguides. These DBRs may include grating features defined by wafer-scale immersion lithography, with an upper layer of erbium-doped aluminum oxide deposited as the final step in the fabrication process. The resulting inverted ridge-waveguide yields high optical intensity overlap with the active medium for both the 980 nm pump (89%) and 1.5 μm laser (87%) wavelengths with a pump-laser intensity overlap of over 93%. The output powers can be 5 mW or higher and show lasing at widely-spaced wavelengths within both the C- and L-bands of the erbium gain spectrum (1536, 1561 and 1596 nm).

An example laser cooling system may include a first laser to induce a transition of a plurality of electrons in a medium to an excited energy state via absorption of photons. The laser cooling system may also include a second laser to stimulate emission from the medium of emitted photons having a higher energy than an energy of the absorbed photons.

A configuration is provided with a laser medium 1 of a refractive index nc that is an isotropic medium and includes an upper surface and a lower surface, where at least one of the upper surface and the lower surface is bonded with a cladding 2 having a refractive index satisfying a relationship of no<nc<ne or ne<nc<no. This allows selective output of only polarized light generated by a refractive index in the cladding 2 smaller than the refractive index nc at a desired wavelength (e.g. 1535 nm) which can be implemented by using the isotropic medium.

Layered glass structures and fabrication methods are described. The methods include depositing soot on a dense glass substrate to form a composite structure and sintering the composite structure to form a layered glass structure. The dense glass substrate may be derived from an optical fiber preform that has been modified to include a planar surface. The composite structure may include one or more soot layers. The layered glass structure may be formed by combining multiple composite structures to form a stack, followed by sintering and fusing the stack. The layered glass structure may further be heated to softening and drawn to control linear dimensions. The layered glass structure or drawn layered glass structure may be configured as a planar waveguide.

The invention relates to phosphate-based glasses suitable for use as a solid laser medium, doped with Er3+ and sensitized with Yb, in “eye-safe” applications. In particular, the invention relates to improving the physical properties of such phosphate-based laser glass composition, particularly with regards to strength of the glass structure and improved thermal shock resistance.

A manufacturing method of a channel type planar waveguide amplifier and a channel type planar waveguide amplifier. The method is to pattern the channel structures on the surface of the optical substrate, and then seal them together with rare earth doped chalcogenide glass into the quartz tube, and finally the channel-type waveguide structure is directly created via the melt-quenching method to achieve high quality planar waveguide amplifier. Excellent side wall roughness can be assured since the present invention does not have any direct etching of rare earth ions. Chemical composition and the activity of the rare earth ions can be maintained since the whole process is not involved in any decomposition of the glass into atoms, ions or clusters as that occurs during the fabrication process of the films deposited by the traditional methods like thermal evaporation and magnetron sputtering.

An erbium-doped bismuth oxide emitting light from high-intensity Er.sup.3+ ions is produced. Provided is a method of producing an erbium-doped bismuth oxide film including: a step of disposing a first sputtering target containing the bismuth oxide, a second sputtering target containing erbium oxide (Er.sub.2O.sub.3), and a substrate in a closed film forming chamber separately from each other; a step of setting the temperature of the substrate to room temperature, introducing H.sub.2O gas into the film forming chamber at a predetermined pressure, and supplying H.sub.2O gas in the vicinity of the substrate; a step of simultaneously sputtering the first sputtering target and the second sputtering target to deposit a part of the first sputtering target and a part of the second sputtering target on the substrate to form a precursor film; and a step of forming a crystalline film by heating the precursor film at a predetermined temperature.

The passively q-switched diode end-pumped solid-state laser is used the gain medium made of Er:Yb doped crystal and the Q-switch made of Co.sup.2+:MgAl.sub.2O.sub.4 crystal. The optical elements are optimally designed for the resonator to achieve pulse energy in a range 0.5 mJ<E<2mJ with the pulse width in a range of 4 ns-15 ns. The resonator is appropriate to use in laser rangefinders, target designator, and other products in military and civilian applications.

The passively q-switched diode end-pumped solid-state laser is used the gain medium made of Er:Yb doped crystal and the Q-switch made of Co.sup.2+:MgAl.sub.2O.sub.4 crystal. The optical elements are optimally designed for the resonator to achieve pulse energy in a range 0.5 mJ<E<2mJ with the pulse width in a range of 4 ns-15 ns. The resonator is appropriate to use in laser rangefinders, target designator, and other products in military and civilian applications.

Methods include directing a laser beam to a target along a scan path at a variable scan velocity and adjusting a digital modulation during movement of the laser beam along the scan path and in relation to the variable scan velocity so as to provide a fluence at the target within a predetermined fluence range along the scan path. Some methods include adjusting a width of the laser beam with a zoom beam expander. Apparatus include a laser source situated to emit a laser beam, a 3D scanner situated to receive the laser beam and to direct the laser beam along a scan path in a scanning plane at the target, and a laser source digital modulator coupled to the laser source so as to produce a fluence at the scanning plane along the scan path that is in a predetermined fluence range as the laser beam scan speed changes along the scan path.