The present invention relates to an optical fiber comprising at least a first end with an first end facet, the optical fiber comprising a core region capable of guiding light at a first wavelength λ; and a microstructured cladding region surrounding said core region. The cladding region comprises an inner cladding region and an outer cladding region. The inner cladding region comprises inner cladding features arranged in an inner cladding background material having a refractive index n
1 , said inner cladding features comprising thermally collapsible holes or voids. The outer cladding region comprising outer cladding features arranged in an outer cladding background material, said outer cladding features comprising solid material with refractive index n
2 , wherein n
2 is lower than n
1 . The invention further relates to methods for splicing such an optical fiber to an optical component and to methods for using such an optical fiber.