Aston University

Aston Photonic Technologies Limited

Ian John Murgatroyd

Catherine Anne Sugden

Karen Elizabeth Chisholm

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

Apparatus for interrogating an optical signal

An optical spectrum analyzer ( ), receiving a multi-channel optical signal ( ). The optical signal ( ) is passed through an optical isolator ( ) and a fiber coupler ( ) to a tunable optical filter. The tunable optical filter comprises one or more fiber Bragg gratings ( ) inscribed in a length of optical fiber. The optical fiber is mounted on a means operable to apply a variable strain to the fiber, to they tune the peak wavelength of the Bragg grating ( ) over a desired wavelength range, the tunable optical filter thereby reflecting each channel of the input signal ( ) in turn. The detector ( ) therefore detects a signal only if the input signal ( ) contains wavelengths corresponding to the reflection wavelength of a grating ( ).

Growing community of inventors

Birmingham, United Kingdom

Ian John Murgatroyd