Abstract: A sensor for sensing pressure is disclosed. The sensor may be a pressure sensor for sensing pressure, or a tactile sensor for sensing tactile events through pressure measurement. In one aspect, the sensor includes at least one pressure sensor having at least one VCSEL on a substrate. It further includes a compressible sensor layer covering a top surface of the at least one VCSEL, and a reflecting element covering a top surface of the sensor layer. A method of manufacturing such a sensor is also disclosed.

Abstract: Fiber structure including a core and a cladding, a central microstructure having a first plurality of longitudinal holes and which is adapted for guiding optical radiation and for birefringence in the core. Also included is a side microstructure having a second plurality of longitudinal holes is provided, wherein the side microstructure partly surrounds the central microstructure and provides a predetermined mechanical anisotropy, a pressure responsive unit for converting an isotropic pressure force to birefringence changes on the core, a lateral force responsive unit for converting a directional pressure force to birefringence changes on the core, a temperature responsive unit for converting temperature to birefringence changes on the core, and a birefringence responsive unit for converting birefringence in the core to wavelength information.

Abstract: A microstructured fiber or photonic crystal fiber is described having a doped solid core region and a cladding region, holes being provided in the cladding region, the fiber having a low hybrid splice loss to conventional fiber as well as being able to be tightly bent due to the microstructured cladding. The cladding region can contain a plurality of holes surrounding and distanced from the core. These holes are preferably located symmetrically around the core and extend longitudinally along the length of fiber. The holes may be two or more D-shaped holes or truncated D-shaped holes arranged symmetrically around the care. In other embodiments, the holes comprise hole structures arranged symmetrically around the core in a ring. The holes may be arranged having the inner side facing the core formed from arcs of a circle, e.g. equal arcs of a circle. Between the arcs circular holes may be provided called capillaries, i.e. smaller holes.

Abstract: Fiber structure including a core and a cladding, a central microstructure having a first plurality of longitudinal holes and which is adapted for guiding optical radiation and for birefringence in the core. Also included is a side microstructure having a second plurality of longitudinal holes is provided, wherein the side microstructure partly surrounds the central microstructure and provides a predetermined mechanical anisotropy, a pressure responsive unit for converting an isotropic pressure force to birefringence changes on the core, a lateral force responsive unit for converting a directional pressure force to birefringence changes on the core, a temperature responsive unit for converting temperature to birefringence changes on the core, and a birefringence responsive unit for converting birefringence in the core to wavelength information.

Abstract: A sensor for sensing pressure is disclosed. The sensor may be a pressure sensor for sensing pressure, or a tactile sensor for sensing tactile events through pressure measurement. In one aspect, the sensor includes at least one pressure sensor having at least one VCSEL on a substrate. It further includes a compressible sensor layer covering a top surface of the at least one VCSEL, and a reflecting element covering a top surface of the sensor layer. A method of manufacturing such a sensor is also disclosed.

Abstract: A microstructured fiber or photonic crystal fiber is described having a doped solid core region and a cladding region, holes being provided in the cladding region, the fiber having a low hybrid splice loss to conventional fiber as well as being able to be tightly bent due to the microstructured cladding. The cladding region can contain a plurality of holes surrounding and distanced from the core. These holes are preferably located symmetrically around the core and extend longitudinally along the length of fiber. The holes may be two or more D-shaped holes or truncated D-shaped holes arranged symmetrically around the care. In other embodiments, the holes comprise hole structures arranged symmetrically around the core in a ring. The holes may be arranged having the inner side facing the core formed from arcs of a circle, e.g. equal arcs of a circle. Between the arcs circular holes may be provided called capillaries, i.e. smaller holes.

Abstract: A multi-mode microlaser and a method for driving a multi-mode broad-area microlaser such as a multi-mode VCSEL is described such that the multi-mode microlaser shows an unexpected Gaussian-like far-field intensity distribution. The driving conditions are in general determined such that a strong reduction of the degree of spatial coherence occurs. For square pulsed driving current, these conditions are determined by the pulse duration pd and the pulse height ph. A Gaussian-like far-field intensity distribution is obtained for pulsed multi-mode broad area microlasers. The typical spatial coherence area corresponding with these driving conditions is substantially independent of the Fresnel number of the microlaser. Additionally, this partial spatial coherence can be tuned by changing the driving conditions, such as e.g. the pulse shape and length.

Abstract: A method is described for setting up a system comprising an active medium. The method comprises thermally controlling the system comprising an active medium by radiative cooling. The radiative cooling thereby is based on stimulated and/or coherent Raman scattering processes. In particular embodiments, the thermally controlling may be obtained by tailoring the efficiencies of the Raman scattering processes by optimising at least one of a number of system parameters. The invention furthermore relates to systems thus obtained, to methods for thermally controlling systems comprising an active medium that generate radiation and to computer program products for performing the methods for setting up systems comprising an active medium and thermally controlled by radiative cooling using stimulated and/or coherent Raman scattering processes.

Abstract: A multi-mode microlaser and a method for driving a multi-mode broad-area microlaser such as a multi-mode VCSEL is described such that the multi-mode microlaser shows an unexpected Gaussian-like far-field intensity distribution. The driving conditions are in general determined such that a strong reduction of the degree of spatial coherence occurs. For square pulsed driving current, these conditions are determined by the pulse duration pd and the pulse height ph. A Gaussian-like far-field intensity distribution is obtained for pulsed multi-mode broad area microlasers. The typical spatial coherence area corresponding with these driving conditions is substantially independent of the Fresnel number of the microlaser. Additionally, this partial spatial coherence can be tuned by changing the driving conditions, such as e.g. the pulse shape and length.

Abstract: A fiber pigtailed network monitoring module incorporating an optical printed circuit board on which a signal-transferring connection is remotely actuated between electronic components mounted on the board and active and/or passive optical devices mounted on the board to generate remotely readable monitoring signals.

Abstract: A connector device for coupling non-aligned optical fibres (19, 20), in which light is directed from one fibre to another by a reflector (12) and lenses (13, 14) and the positional relationship between the ends of the optical fibres and the reflector is determined by means (31, 32, 33) for locating the end of each optical fibre to be coupled in a predetermined position both parallel to and transverse the length of the fibre. Also covers a connector device for optically coupling an optical fibre (101, FIG. 14) to deliver light to or receive light from another optical component (102) by way of a lens (110), in which the positional relationship between the end of the optical fibre and the said other optical component is determined by means (106) for locating the end of the said optical fibre in a predetermined position both parallel to and transverse the length of the fibre with respect to the said optical component.

Abstract: A connector device for coupling non-aligned optical fibres (19, 20), in which light is directed from one fibre to another by a reflector (12) and lenses (13, 14) and the positional relationship between the ends of the optical fibres and the reflector is determined by means (31, 32, 33) for locating the end of each optical fibre to be coupled in a predetermined position both parallel to and transverse the length of the fibre. Also covers a connector device for optically coupling an optical fibre (101, FIG. 14) to deliver light to or receive light from another optical component (102) by way of a lens (110), in which the positional relationship between the end of the optical fibre and the said other optical component is determined by means (106) for locating the end of the said optical fibre in a predetermined position both parallel to and transverse the length of the fibre with respect to the said optical component.

Abstract: The present invention relates to vertical-cavity surface-emitting lasers (VCSELs), and more particularly to a method and apparatus for controlling and stabilization of polarization in such devices. The method for stabilizing the polarization of light generated by a VCSEL assembly comprising a light generation region of a VCSEL, the VCSEL being mechanically coupled to a mounting substrate, comprises the steps of: mechanically coupling the mounting substrate to a second substrate which is coextensive or larger in area than the mounting substrate, and applying uniaxial strain to the light generation region of the VCSEL by means of external strain applied to the mounting substrate by the second substrate or by means attached to the second substrate.

Abstract: The present invention relates to vertical-cavity surface-emitting lasers (VCSELs), and more particularly to a method and apparatus for controlling and stabilization of polarization in such devices.