A temperature sensor for sensing changes in temperature up to a predetermined temperature, including: a microstructured optical fiber the microstructured optical fiber including an outer cladding portion and an inner suspended core extending longitudinally along the temperature sensor and a plurality of longitudinal channels (340a-c, 440a-c) surrounding the inner suspended core and extending along the microstructured optical fiber to form a suspended core microstructured optical fiber ; a fiber Bragg grating formed in the suspended core microstructured optical fiber by generating a periodic modulation in the refractive index along a core region of the inner suspended core of the suspended core microstructured optical fiber , wherein the fiber Bragg grating is operable to produce band reflection at a reflection wavelength that varies in accordance with changes in temperature at the core region of the optical fiber, wherein the periodic modulation in the refractive index along the core region is formed by laser ablating defects along the core region, wherein the structure of the suspended core microstructured optical fiber is configured to facilitate the laser ablating of defects along the core region of the suspended core microstructured optical fiber by including a single longitudinal access channel extending between the core region and the outer cladding portion of the suspended core microstructured optical fiber to provide laser access to the core region through only the outer cladding portion; the temperature sensor characterized by the structure of the suspended core microstructured optical fiber being further configured to facilitate the laser ablating of defects along the core region by configuring a cross-sectional geometry of the single longitudinal access channel to assist the focusing of a laser through the outer cladding portion onto a surface of the core region. a microstructured optical fiber the microstructured optical fiber including an outer cladding portion and an inner suspended core extending longitudinally along the temperature sensor and a plurality of longitudinal channels (340a-c, 440a-c) surrounding the inner suspended core and extending along the microstructured optical fiber to form a suspended core microstructured optical fiber ; a fiber Bragg grating formed in the suspended core microstructured optical fiber by generating a periodic modulation in the refractive index along a core region of the inner suspended core of the suspended core microstructured optical fiber , wherein the fiber Bragg grating is operable to produce band reflection at a reflection wavelength that varies in accordance with changes in temperature at the core region of the optical fiber, wherein the periodic modulation in the refractive index along the core region is formed by laser ablating defects along the core region, wherein the structure of the suspended core microstructured optical fiber is configured to facilitate the laser ablating of defects along the core region of the suspended core microstructured optical fiber by including a single longitudinal access channel extending between the core region and the outer cladding portion of the suspended core microstructured optical fiber to provide laser access to the core region through only the outer cladding portion; the temperature sensor characterized by the structure of the suspended core microstructured optical fiber being further configured to facilitate the laser ablating of defects along the core region by configuring a cross-sectional geometry of the single longitudinal access channel to assist the focusing of a laser through the outer cladding portion onto a surface of the core region. <EOS>