Disclosed is a planar waveguide including: a core (11) which is a flat plate through which light propagates; a cladding (12) which is a flat plate for reflecting the light in a state of being joined to an upper surface of the core (11); and a cladding (13) which is a flat plate for reflecting the light in a state of being joined to a lower surface of the core (11), in which each of the claddings (12) and (13) is a multilayer film in which multiple films made from different materials are layered. As a result, a material having a low index of refraction can be used as the material of the core (11), and the limit on materials usable as the material of the core (11) is relaxed.

An Nd.sup.3+ optical fiber laser and amplifier operating in the wavelength range from 1300 to 1450 nm is described. The fiber includes a rare earth doped optical amplifier or laser operating within this wavelength band is based upon an optical fiber that guides light in this wavelength band. The waveguide structure attenuates light in the wavelength range from 850 nm to 950 nm and from 1050 nm to 1150 nm.

The invention relates to an optical waveguide (3) as a laser medium or as a gain medium for high-power operation, wherein the optical waveguide (3) is an optical fiber, the light-guiding core of which, at least in sections, is doped with rare earth ions. It is an object of the invention to provide an optical waveguide as a laser or a gain medium, and a laser/amplifier combination realized therewith, in which the output signal of the laser or gain medium is better stabilized. The invention achieves this object by virtue of the maximum small signal gain of the optical waveguide (1) being up to 60 dB, preferably up to 50 dB, more preferably up to 40 dB, even more preferably up to 30 dB, on account of the concentration of the rare earth ions and/or the distribution thereof in the light-guiding core. Moreover, the invention relates to the use of such an optical waveguide as an amplifier fiber (3) in a laser/amplifier combination.

A uniform temperature profile is provided across the width of the core of a ribbon fiber laser or amplifier by the use of insulating elements at the core edges and a spatially variable gain in the fiber core. High average power ribbon fibers, enable a variety of applications such as practical laser cutting and beam combining.

Systems and methods described herein may include a first semiconductor layer with a first lattice constant, a rare earth pnictide buffer epitaxially grown over the first semiconductor, wherein a first region of the rare earth pnictide buffer adjacent to the first semiconductor has a net strain that is less than 1%, a second semiconductor layer epitaxially grown over the rare earth pnictide buffer, wherein a second region of the rare earth pnictide buffer adjacent to the second semiconductor has a net strain that is a desired strain, and wherein the rare earth pnictide buffer may comprise one or more rare earth elements and one or more Group V elements. In some examples, the desired strain is approximately zero.

A laser illumination or dazzler device and method. More specifically, examples of the present invention provide laser illumination or dazzling devices power by one or more violet, blue, or green laser diodes characterized by a wavelength from about 390 nm to about 550 nm. In some examples the laser illumination or dazzling devices include a laser pumped phosphor wherein a laser beam with a first wavelength excites a phosphor member to emit electromagnetic at a second wavelength. In various examples, laser illumination or dazzling devices according to the present invention include polar, non-polar, or semi-polar laser diodes. In a specific example, a single laser illumination or dazzling device includes a plurality of violet, blue, or green laser diodes. There are other examples as well.

A structure can include a III-N layer with a first lattice constant, a first rare earth pnictide layer with a second lattice constant epitaxially grown over the III-N layer, a second rare earth pnictide layer with a third lattice constant epitaxially grown over the first rare earth pnictide layer, and a semiconductor layer with a fourth lattice constant epitaxially grown over the second rare earth pnictide layer. A first difference between the first lattice constant and the second lattice constant and a second difference between the third lattice constant and the fourth lattice constant are less than one percent.

A quantum device for interfacing Lanthanide ions with optical fields or microwave fields or both. The device includes waveguides or resonators or both for optical fields or microwave fields or for both. The device includes at least one surface to which a single customized Lanthanide molecular complex, or an ensemble, layer, multilayer or crystal of such, are attached or bonded. This places the Lanthanide ions within the optical or microwave fields or both. The ability to customize the molecular structure around each Lanthanide ion, and to control their orientation and position and nano-environment in general, enables minimizing the host lattice effects and non-radiative loss channels for each ion, and increasing their homogeneity. Accordingly, the advantages of the present invention include reduced inhomogeneities, narrower linewidths, extended fluorescence and coherence times, and higher operation temperatures. Devices which benefit from the present invention include lasers, amplifiers, sensors, quantum memories, repeaters and quantum information processing devices at optical fields, microwave fields, or both, including bi-directional optical-microwave convertors.

A higher-order mode (HOM) fiber is configured as a polarization-maintaining fiber by including a pair of stress rods at a location within the cladding layer that provides for a sufficient degree of birefringence without unduly comprising the spatial mode profile of the propagating higher-order modes. Long-period gratings are used as mode couplers at the input and output of the PM-HOM fiber, where the gratings are formed by exposing areas of the core region orthogonal to the position of the stress rods. The diameter of the stress rods (D) and displacement of the rods from the center of the core region (R1) are controlled to yield a configuration with an acceptable birefringence and polarization extinction ratio (PER) within the HOM fiber, even in situations where the fiber is bent (a bend radius less than 50 cm).

An electro-optic (EO) sensor and a method for detecting a local electric field strength, the EO sensor including: a first optical cavity; a gain medium within the first optical cavity; a mode locking element within the first optical cavity; and an EO material within the first optical cavity, an effective optical path length of the EO material being variable depending on the local electric field strength at the EO sensor, wherein the gain medium, the mode locking element, and the EO material are arranged in a common path of light within the first optical cavity, and wherein during operation, the EO sensor emits pulses of light at a repetition rate characteristic of an effective optical path length of the light within the first optical cavity, the effective optical path length varying depending on the electric field strength local to the EO sensor.