Abstract: Apparatus (10) for interrogating an optical signal (not shown) propagating in an optical waveguide, such as an optical fiber, having an input section (12) and a second section (14) through which light entering from the input section (12) will subsequently propagate. The second section (14) includes a grating portion, such as a tilted chirped fiber Bragg grating (16). The grating (16) causes at least part of the optical signal to be coupled out of the optical fiber, through the fiber cladding. A photodetector (18) is provided generally alongside the grating (16). The photodetector (18) is arranged to collect and detect substantially all of the outcoupled optical signal. The relationship between the optical power outcoupled by the grating (16) and the wavelength of the optical signal is known, allowing a measurement of the outcoupled optical power to be used to determine the wavelength of the optical signal propagating through the grating (16).

Abstract: Apparatus (10) for interrogating an optical signal (not shown) propagating in an optical waveguide, such as an optical fibre, having an input section (12) and a second section (14) through which light entering from the input section (12) will subsequently propagate. The second section (14) includes a grating portion, such as a tilted chirped fibre Bragg grating (16). The grating (16) causes at least part of the optical signal to be coupled out of the optical fibre, through the fibre cladding. A photodetector (18) is provided generally alongside the grating (16). The photodetector (18) is arranged to collect and detect substantially all of the outcoupled optical signal. The relationship between the optical power outcoupled by the grating (16) and the wavelength of the optical signal is known, allowing a measurement of the outcoupled optical power to be used to determine the wavelength of the optical signal propagating through the grating (16).

Abstract: An improved device or tool is provided for cleaving angled ends on to at least one optical fiber (1) (FIG. 1) in which spring means (6) and co-operating pivotally mounted clamping blocks (7a, 7b) are employed to clamp and tension the optical fiber (1) with tension (T). A sharp corner edge (11) of an anvil (10) is used to locally deflect or displace the fiber (1) and bend it about the opposing sharp corner edge (12) of the clamping surface (5) of one of the clamping blocks (viz 7b) so that the fiber experiences a localized shear force. The resultant stress is a superposition of tension and shear and is directed away from the axis of the fiber (1). An acutely angled blade (13) is operable to score the fiber (1) at a point between the two opposing corners (11, 12). The fiber (1) cleaves with ends which are consistently angled at between 1° and 20° (preferably 5° to 10°) away from the perpendicular to the fiber axis.

Abstract: An improved device or tool is provided for cleaving angled ends onto at least one optical fiber (1) in which spring means (6) and co-operating pivotally mounted clamping blocks (7a, 7b) are employed to clamp and tension the optical fiber (1) with tension (T). A sharp corner edge (11) of an anvil (10) is used to locally deflect or displace the fiber (1) and bend it about the opposing sharp corner edge (12) of the clamping surface (5) of one of the clamping blocks (viz 7b) so that the fiber experiences a localised shear force. The resultant stress is a superposition of tension and shear and is directed away from the axis of the fiber (1). An acutely angled blade (13) is operable to score the fiber (1) at a point between the two opposing corners (11, 12). The fiber (1) cleaves with ends which are consistently angled at between 1° and 20° (preferably 5° to 10°) away from the perpendicular to the fiber axis.