Optical spectrum analyzer
First Claim
1. An optical spectrum analyser comprising:
- a length of optical fibre for receiving an input optical signal;
a tunable optical filter in optical communication with the input fibre, the tunable optical filter including a first in-fibre Bragg grating inscribed in a first section of fibre, and means operable to apply a variable axial force to the first section of fibre, to thereby tune the peak wavelength of the grating over a desired wavelength range; and
optical detection means operable to detect an optical signal selected by the tunable optical filter.
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Accused Products
Abstract
An optical spectrum analyzer (10), receiving a multi-channel optical signal (12). The optical signal (12) is passed through an optical isolator (14) and a fiber coupler (16) to a tunable optical filter. The tunable optical filter comprises one or more fiber Bragg gratings (18) 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 (18) over a desired wavelength range, the tunable optical filter thereby reflecting each channel of the input signal (12) in turn. The detector (20) therefore detects a signal only if the input signal (12) contains wavelengths corresponding to the reflection wavelength of a grating (18).
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Citations
87 Claims
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1. An optical spectrum analyser comprising:
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a length of optical fibre for receiving an input optical signal;
a tunable optical filter in optical communication with the input fibre, the tunable optical filter including a first in-fibre Bragg grating inscribed in a first section of fibre, and means operable to apply a variable axial force to the first section of fibre, to thereby tune the peak wavelength of the grating over a desired wavelength range; and
optical detection means operable to detect an optical signal selected by the tunable optical filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86)
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87. A tunable optical filter comprising:
- two in-fibre Bragg gratings inscribed in first and second sections of optical fibre respectively, the spectra of the gratings having different peak wavelengths, and means operable to apply a variable axial force to one or each of the first and second sections of fibre, to thereby tune the peak wavelength of the or each grating over a desired wavelength range.
Specification