Abstract: The present invention relates to a device for outcoupling of light in an external cavity laser, which external cavity laser comprises at least one light source, at least one wavelength selective feedback element, at least one polarization selective beam-splitting optical element, and at least one Faraday-rotator element.

Abstract: A broad stripe semiconductor laser has a folded cavity that permits the laser to produce output powers into a high quality beam with low divergence. The folded cavity includes a first material region disposed within the cavity having a first refractive index and a second material region having a second refractive index less than the first refractive index, and forming a first interface with the first material region. The first interface is disposed to reflect a lowest order reflection mode light beam propagating within the first material region. The first interface is disposed at a predetermined angle so that the lowest order reflection mode intracavity light beam is incident on the first interface at an angle below the critical total internal reflection angle, and higher order reflection modes are incident on the first interface at angles in excess of the total internal reflection critical angle. The interface may be curved to control the divergence to the light emitted from the cavity.

Abstract: High power semiconductor lasers for pumping fiber devices, such as fiber amplifiers and fiber lasers, include an optical gain region disposed between a rear end and the output end, the width of the optical gain region being greater at the output end than at the rear end. The optical gain region may include a single mode channel region coupled to a flared amplifier region. The light output from the laser is coupled via a lens system into a fiber for propagating to the fiber device to be pumped. Light is fedback into the laser, for example from a fiber Bragg grating, to induce the laser to operate in coherence collapse. The broad bandwidth output associated with coherence collapse permits the laser to deliver high optical powers into the fiber without the onset of stimulated Billion scattering. Fiber grating feedback improves the quality of the beam output by the laser, thus enhancing coupling efficiency into the fiber. The pump laser may be used to pump multiple fiber devices.

Abstract: The present invention relates to a device for outcoupling of light in an external cavity laser, which external cavity laser comprises at least one light emitting and/or amplifying element (300, 500, 600, 700, 800), at least one wavelength selective feedback element (340, 540, 640, 740, 840). The outcoupling device further comprises at least one polarization selective beam-splitting optical element (320, 520, 620, 720, 820), and at least one Faraday-rotator element (330, 530, 630, 730, 830).

Abstract: A semiconductor gain element has an active waveguide incident at an angle greater than normal incidence on an end facet. The waveguide may be a single stripe or may be a stripe coupled to a flared region. The waveguide may include a curved portion to produce the non-normal incidence on the end facet. The gain element may be used as the gain element within a tunable, external cavity laser, or may also be used as an amplifier to amplify an external signal. The waveguide may be formed from a central portion surrounded laterally by cladding regions. Further, absorbing regions may be positioned outside the cladding regions to absorb light that does not propagate within the waveguide.

Abstract: A semiconductor gain element has an active waveguide incident at an angle greater than normal incidence on an end facet. The waveguide may be a single stripe or may be a stripe coupled to a flared region. The waveguide may include a curved portion to produce the non-normal incidence on the end facet. The gain element may be used as the gain element within a tunable, external cavity laser, or may also be used as an amplifier to amplify an external signal. The waveguide may be formed from a central portion surrounded laterally by cladding regions. Further, absorbing regions may be positioned outside the cladding regions to absorb light that does not propagate within the waveguide.

Abstract: A semiconductor gain element has an active waveguide incident at an angle greater than normal incidence on an end facet. The waveguide may be a single stripe or may be a stripe coupled to a flared region. The waveguide may include a curved portion to produce the non-normal incidence on the end facet. The gain element may be used as the gain element within a tunable, external cavity laser, or may also be used as an amplifier to amplify an external signal. The waveguide may be formed from a central portion surrounded laterally by cladding regions. Further, absorbing regions may be positioned outside the cladding regions to absorb light that does not propagate within the waveguide.

Abstract: As to a first feature, a semiconductor optoelectronic device includes a resonator having an optical cavity between opposite end facets, a larger portion of a length of the resonator cavity comprising a single mode confining region for propagation of light and a smaller portion of a length of the resonator cavity comprising a tapered region for permitting propagation of light with a diverging phase front to a first of the end facets, which first facet is the light beam output. The tapered region provides a sufficiently large aperture to prevent catastrophic optical mirror damage (COD) at the first end facet while reducing the amount of required astigmatism correction while the single mode confining region provides spatial filtering to maintain diffraction-limited beam at the output. This structure therefore, more readily lends itself for incorporation into existing device packages designed for linear stripe laser diodes devices.

Abstract: A method of determining the filler content of paper, wherein the paper stock is examined prior to delivering the stock to the de-watering section of the paper machine, and wherein the volume concentration of particles in the stock that have a size which is greater than the characteristic size of the filler is determined at varying mechanical working of the pulp, and the amount of filler retained in the paper is predicted from the result of at least two such determinations.