Abstract: A single-mode optical fiber for guiding an optical signal, wherein the core region is capable of guiding an optical signal in a fundamental core mode at an optical signal wavelength. A cladding region is arranged to surround the core region and includes an inner cladding region and an outer cladding region. The inner cladding region includes a background material and a plurality of inner cladding features arranged in the background material, wherein a plurality of the plurality of inner cladding features are of a first type of feature that includes an air hole surrounded by a high-index region comprising a high-index material that is larger than the refractive index of the inner cladding background material.

Abstract: A single-mode optical fiber for guiding an optical signal, wherein the core region is capable of guiding an optical signal in a fundamental core mode at an optical signal wavelength. A cladding region is arranged to surround the core region and includes an inner cladding region and an outer cladding region. The inner cladding region includes a background material and a plurality of inner cladding features arranged in the background material, wherein a plurality of the plurality of inner cladding features are of a first type of feature that includes an air hole surrounded by a high-index region comprising a high-index material that is larger than the refractive index of the inner cladding background material.

Abstract: An optical fibre that use index-guidance formed with a low index cladding or a microstructured cladding using voids/holes or low index features (404) together with multiple high index resonant cladding features (1205, 1206). One to three resonant cross sectional extending structure act as a filter by resonantly coupling light out to part of the cladding (1202) or other structures (fx. a high index outer cladding ring) that acts as light sink(s) at one to three wavelength when using one to three materials or features with different size, shape, refractive index profile or normalized frequency parameter. The fibre can be asymmetrical. The fibre can be adapted for suppression of higher order modes (HOM) and/or guiding light in a narrow spectral wavelength range and act as a band pass filter.

Abstract: An optical fibre that use index-guidance formed with a low index cladding or a microstructured cladding using voids/holes or low index features (404) together with multiple high index resonant cladding features (1205, 1206). One to three resonant cross sectional extending structure act as a filter by resonantly coupling light out to part of the cladding (1202) or other structures (fx. a high index outer cladding ring) that acts as light sink(s) at one to three wavelength when using one to three materials or features with different size, shape, refractive index profile or normalized frequency parameter. The fibre can be asymmetrical. The fibre can be adapted for suppression of higher order modes (HOM) and/or guiding light in a narrow spectral wavelength range and act as a band pass filter.

Abstract: A package comprises a substrate (101, 401) with a longitudinal direction and a lateral direction perpendicular thereto. The substrate (101, 401) has a recess (103, 403) formed in a first surface (102, 402) and the recess (103, 403) extends in the longitudinal direction of the substrate (101, 401), said recess (103, 403) having an inner surface. The inner surface of the recess (103, 403) comprises at least a first set of conductive areas. The first set comprises at least a first area (106, 406) and a second area (107, 407) being provided with a conductive layer, said first area (106, 406) and said second area (107, 407) being mutually spaced in the lateral direction. The package additionally comprises a cap (151, 251, 351, 451.) with a first surface (152, 252, 352, 452) for mounting on top of said first surface (102, 402) of said substrate (101, 401), the cap (151, 251, 351, 451) and the recess (103, 403) of the substrate (101, 401) defining an elongated channel in the longitudinal direction.

Abstract: A package comprises a substrate (101, 401) with a longitudinal direction and a lateral direction perpendicular thereto. The substrate (101, 401) has a recess (103, 403) formed in a first surface (102, 402) and the recess (103, 403) extends in the longitudinal direction of the substrate (101, 401), said recess (103, 403) having an inner surface. The inner surface of the recess (103, 403) comprises at least a first set of conductive areas. The first set comprises at least a first area (106, 406) and a second area (107, 407) being provided with a conductive layer, said first area (106, 406) and said second area (107, 407) being mutually spaced in the lateral direction. The package additionally comprises a cap (151, 251, 351, 451.) with a first surface (152, 252, 352, 452) for mounting on top of said first surface (102, 402) of said substrate (101, 401), the cap (151, 251, 351, 451) and the recess (103, 403) of the substrate (101, 401) defining an elongated channel in the longitudinal direction.