Back to results
US 6,445,847 B1Granted
Apparatus and method for achieving a smooth spectral response optical filter
AssigneeLucent Technologies Inc.
InventorChristopher Richard Doerr
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeLucent Technologies Inc.
InventorChristopher Richard Doerr
Estimating the term…
A design technique minimizes the loss and ripple in the spectral response of an optical filter formed using a pair of gratings connected by an array of optical elements. This filter can be, for example, two waveguide grating routers (WGRs) connected by an array of waveguides. Each WGR includes two star couplers connected by waveguide grating arms. The smoothest spectral response is achieved for a given set of connecting waveguides, by choosing the number of grating arms less than or equal to filling the star coupler central Brillouin zone made by the set of connecting waveguides resulting in the connecting waveguides neither substantially over- or under-sampling the optical spectrum from the waveguide gratings. Exactly filling the Brillouin zone with the grating arms minimizes the loss, and so is the preferred choice.
An optical filter including one or more waveguide grating routers connected to a set of waveguides, each waveguide grating router comprising a pair of star couplers interconnected by a waveguide grating, each waveguide grating router characterized in that
The optical filter of claim 2 wherein one or more of the connecting set of waveguides contain an optical element selected from a group including a phase shifter, a switch, a shutter, a coupler, a polarization converter, an amplifier, and a mirror.
The optical filter of claim 2 wherein the waveguide grating router and waveguides are arranged to form a wavelength equalizer, a programmable filter, or a wavelength add/drop unit.
A method of producing a low-loss and an essentially ripple-free spectral response optical filter from one or more waveguide grating routers connected to a set of waveguides, each waveguide grating router comprising a pair of star couplers interconnected by a waveguide grating, the method including the steps of:
Dependencies are inferred from the claim text.