US 2001/0033714 A1 · Method and apparatus for reducing the wavelength dependency of an integrated optical filter

Abstract

The present invention relates to an optical filter comprising an integrated wavelength dispersive element having an input for providing temperature compensation, particularly for providing passive temperature compensation in an arrayed waveguide grating. The present invention has found that by providing an arrayed waveguide grating having a thermally responsive pivotal input structure for changing an angle of a collimated input signal launched into a focusing lens, the input point can be selected in response to changing temperature in order to compensate for thermal drift of the center wavelength. Further, the present invention has found that by providing a reflective lens assembly for focusing an input signal at a selected input point of the input planar waveguide, alignment and tuning of an input and assembly can be improved and simplified. As an additional advantage, variable coupling parameters can be incorporated into a reflective coupling including input position, waveguide taper and planar waveguide length increment to provide relatively simple tuning in an integrated device.

Claims22

Dependent claims

An input coupling for launching light into a planar waveguide of an integrated wavelength dispersive element comprising:

focusing means having optical power for focusing light at an input point on the input plane of the planar waveguide;
an input waveguide for launching a signal comprising a plurality of channels at specific wavelengths into the integrated wavelength dispersive element;
means for coupling the signal as a beam into the focusing means;
and,
tilt means including a pivotal structure having a center of rotation and a thermally responsive actuator, for imparting a tilt on the beam coupled to the focusing means in response to a change in temperature.

2 more elements

An arrayed waveguide grating comprising:

a substrate for supporting an integrated arrayed waveguide grating formed therein including:
an input planar waveguide, having an input plane at an edge of the substrate and an output plane, for propagating a wavefront from an input point on the input plane to an output plane;
a grating comprising an array of waveguides optically coupled to the output plane of the input planar waveguide for receiving the wavefront, an optical length of the waveguides differing by a substantially equal amount from a first waveguide to an nth waveguide;
and,
an output planar waveguide for focusing separated wavelength signals on an output plane of the output planar waveguide for coupling to output waveguides;
and
an input coupling for launching a signal into the integrated arrayed waveguide grating including:
at least one input waveguide;
a lens for focusing an input signal at the input point of the input planar waveguide.
means for coupling the signal as a collimated beam into the lens;
and,
tilt means including a pivotal structure having a center of rotation and a thermally responsive actuator, for imparting a tilt on the collimated beam at a focal plane of the lens in response to a change in temperature.

9 more elements

Dependencies are inferred from the claim text.

Method and apparatus for reducing the wavelength dependency of an integrated optical filter

Life of this patent

Method and apparatus for reducing the wavelength dependency of an integrated optical filter

Life of this patent

Abstract

Claims22