A laser pumping assembly includes a parallelepipedal solid laser medium having the shape of a plate in a horizontal plane (xy) and a thickness e.sub.L, the laser medium having an absorption spectral band and an associated absorption coefficient α; at least one light emission module intended to pump the laser medium, comprising a fluorescent parallelepipedal crystal called a concentrator, having the shape of a plate of thickness e.sub.c′, the concentrator having at least one illumination face illuminated by electroluminescent radiation and being configured to absorb the electroluminescent radiation and emit fluorescence radiation in a spectral range exhibiting an overlap with the absorption spectral band, the concentrator having an emitting face; the concentrator being in optical contact, via the emitting face, with a receiving face of the laser medium, the concentrator being arranged perpendicular to the laser medium such that the one or more illumination faces are perpendicular to the receiving face so as to perform transverse pumping of the laser medium, the optical contact being designed such that a portion of the fluorescence radiation trapped in the concentrator by total internal reflection is able to pass into the laser medium by passing through the emitting face, and be trapped in the laser medium by total internal reflection, the thickness e.sub.l of the laser medium being such that e.sub.L≤L.sub.abs/5 where L.sub.abs=1/α is an absorption length of the laser medium.

Hybrid silicon devices are disclosed in which a silicon-based resonant structure is coated with a rare-earth-doped tellurium oxide layer that facilitates optical gain, thereby forming a silicon-based laser cavity. The silicon-based laser cavity supports at least one resonant mode that has a modal volume extending from the silicon resonant base structure into the rare-earth-doped tellurium oxide layer. The silicon-based laser cavity is optically coupled to a silicon waveguide to facilitate the delivery of pump laser energy to the silicon-based laser cavity, such that at least a portion of the pump laser energy propagating through the silicon waveguide is coupled to the silicon-based laser cavity for excitation of the rare earth dopant within the rare-earth-doped tellurium oxide layer. The silicon waveguide that is optically coupled to the silicon-based laser cavity also facilitates the external delivery of the laser energy generated within silicon-based laser cavity.

An optical oscillator includes a first reflection part configured to reflect light of a first wavelength, a laser medium excited by excitation light of a second wavelength different from the first wavelength and configured to emit light of the first wavelength, a second reflection part configured to form an unstable resonator together with the first reflection part, the unstable resonator being configured to output annular laser light of the first wavelength, and a saturable absorption part disposed between the laser medium and the second reflection part and of which a transmittance increases with absorption of light of the first wavelength. When a power of the excitation light is indicated by P.sub.p (kW), and an inner diameter of the annular laser light is indicated by d.sub.i, and an outer diameter is indicated by d.sub.o, and d.sub.o/d.sub.i is a magnification m, the magnification m satisfies a.sub.0+a.sub.1 Log(P.sub.p)≤m≤b.sub.0+b.sub.1P.sub.p+b.sub.2P.sub.p.sup.2.

A gain mirror is created for use as an optical amplifier in a solid state ring laser rotation sensor. Such a ring laser includes at least three mirrors for reflecting counter propagating laser beams around a closed loop optical path, wherein at least one of the mirrors is a gain mirror. The gain mirror is formed by applying a thin film of silica, a few half wavelengths thick and doped with Nd isotopes, onto a very high reflectivity mirror and then using a laser diode to pump it with intense light to form a population inversion in Nd.sup.3+ ions. An assembly consisting of this gain mirror and a pump laser diode can be used as an optical amplifier in a solid state ring laser to generate the two counter propagating laser light beams needed to measure rotation.

A technique which is suitable in joining an end surface of a laser medium to a transparent heat sink for maintaining thermal resistance therebetween low and avoiding large thermal stress from acting on the laser medium is to be provided. An end coat is provided on the end surface of the laser medium, a same-material layer constituted of a same material as the heat sink is provided on a surface of the end coat, a surface of the same-material layer and an end surface of the heat sink are activated in a substantially vacuum environment, and those activated surfaces are bonded in the substantially vacuum environment. A laser apparatus having low thermal resistance between the laser medium and the heat sink and high transparency at a joint interface therebetween, and no large thermal stress acting on the laser medium is thereby obtained.

A laser system comprising an RE:XAB gain medium within a resonator cavity. X is selected from Ca, Lu, Yb, Nd, Sm, Eu, Gd, Ga, Tb, Dy, Ho, Er, and RE is selected from Lu, Y, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Pr, Tm, Cr, Ho. The system further comprises a pumping source having optical output directed towards the gain medium. A laser controller operates the pumping source. The system further comprises a heat spreader, the heat spreader in thermal communication with the gain medium through a surface wherein the pump source has optical output incident.

A method for manufacturing an optical element is a method for manufacturing an optical element in which laser light is transmitted, reciprocated, or reflected, and the method includes a first step of obtaining a bonded element formed by subjecting a first element part and a second element part, both being transparent to laser light, to surface activated bonding with a non-crystalline layer interposed therebetween; and after the first step, a second step of crystallizing at least a portion of the non-crystalline layer by raising the temperature of the bonded element. In the second step, the temperature of the bonded element is raised to a predetermined temperature that is lower than the melting points of the first element part and the second element part.

Passively Q-switched lasers and short wave infrared (SWIR) electro-optical systems including such lasers. A passively Q-switched laser may include a gain medium (GM) having a stimulated emission cross section σ.sub.SE, a saturable absorber (SA) having an absorption cross section (σ.sub.a) which is less than three times the σ.sub.SE of the GM, and an optical resonator within which the GM and the SA are positioned, the optical resonator comprising a high reflectivity mirror and an output coupler, wherein at least one of the high reflectivity mirror and the output coupler comprises a curved mirror, directing light within the optical resonator such that an effective cross-section of a laser mode within the SA (A.sub.SA) is smaller than a cross-section of a laser mode within a Rayleigh length of the pump (A.sub.GM).

A tunable microwave source based on dual-wavelength lasing of a single optical whispering gallery microcavity includes a dual-wavelength laser having the single optical whispering gallery microcavity for generating dual-wavelength lasing with adjustable spacing, narrow linewidth and low threshold; an optical fiber or waveguide amplifier for optical signal amplification; an optical filter for optical signal and noise filtration; and a high-speed detector for generating a tunable microwave signal with narrow bandwidth. The dual-wavelength laser includes a pump source, the optical whispering gallery microcavity, an optical waveguide or a tapered optical fiber, a microcavity substrate, and a gold electrode pair. The frequency spacing of the dual-wavelength lasing is tuned by adjusting the external voltage of the gold electrode pair.

The laser amplification apparatus is provided with a plurality of plate-shaped laser medium components (M1 to M4) which are disposed to be aligned along a thickness direction, and prisms (P1 to P3) which optically couples the laser medium components. Each of the laser medium components is provided with a main surface to which a seed light is incident, and a side surface which surrounds the main surface. An excitation light is incident from at least one side surface of a specific laser medium component among the plurality of laser medium components. The excitation light is incident through the prism to a side surface of the laser medium component adjacent to the prism.