Optical waveguide bragg grating system
First Claim
1. An optical waveguide Bragg grating system comprising a length of optical waveguide having a plurality of Bragg grating locations spaced apart along its length, each grating location containing a plurality of Bragg gratings formed thereat, each of the gratings at a respective location having a characteristic response wavelength different from the other gratings at that location, each location being assigned a unique digital code representative of a unique set of response wavelengths of the gratings at that location, an optical source for providing an optical signal to the optical waveguide, the signal having a bandwidth which includes the response wavelength of each grating at each location, a correlator for correlating in wavelength space combined optical responses from all locations with. each code, whereby. the responses from each grating location may be uniquely determined.
2 Assignments
0 Petitions
Accused Products
Abstract
An optical wavelength Bragg grating system has a length of optical waveguide (2) containing a set of Bragg gratings (10, 20, 30) at each of a number of locations along the fibre. Each location is assigned a unique digital code defining the wavelength set (λ1, λ4, λ7; λ1, λ5, λ9; λ3, λ6, λ8) of the gratings at that location. The waveguide (2) is coupled to a wide-band optical source (5) and the combined response from all the grating locations is correlated (16) with each digital code to discriminate responses from the respective grating locations.
6 Citations
11 Claims
- 1. An optical waveguide Bragg grating system comprising a length of optical waveguide having a plurality of Bragg grating locations spaced apart along its length, each grating location containing a plurality of Bragg gratings formed thereat, each of the gratings at a respective location having a characteristic response wavelength different from the other gratings at that location, each location being assigned a unique digital code representative of a unique set of response wavelengths of the gratings at that location, an optical source for providing an optical signal to the optical waveguide, the signal having a bandwidth which includes the response wavelength of each grating at each location, a correlator for correlating in wavelength space combined optical responses from all locations with. each code, whereby. the responses from each grating location may be uniquely determined.
- 6. An optical CDMA data communications system comprising a length of optical waveguide having a plurality of Bragg grating locations spaced apart along its length, each grating location containing a plurality of Bragg gratings formed thereat, each of the gratings at a respective location having a characteristic response wavelength different from the other gratings at that location, each location being assigned a unique digital code representative of a unique set of response wavelengths of the gratings at that location and having a respective reflective tap, a plurality of optical sources coupled to the. optical waveguide, each source having a unique respective wavelength corresponding to the characteristic response wavelength of a different respective one of the gratings at the plurality of Bragg grating locations, a data input for feeding data intended to be received at the reflective tap of a grating location to each optical source having a wavelength corresponding to the characteristic response wavelength of each grating at said grating location and a correlator coupled to each reflective tap for correlating in wavelength space optical signals received at a respective tap with each digital code, whereby data signals intended for that tap may be discriminated
Specification