Apparatus comprising a distributed coupled-cavity waveguide reflector
AssigneeQuintessent Inc.
InventorMichael Davenport
Life of this patent
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Abstract
Coupled-cavity waveguide reflectors suitable for use in high-Q reflective spectral filters, narrow-linewidth lasers, and the like, are presented. Coupled-cavity waveguide reflectors in accordance with the present disclosure comprise multiple waveguide segments arranged in a series, each segment including a tooth having relatively higher refractive index and a gap having relatively lower refractive index, where the lengths of the teeth and gaps are based on the position of their respective segments in the series. The lengths of the teeth and gaps are selected such that the reflectivity of the segments align at only a single wavelength, thereby enabling very narrow-linewidth operation.
Claims36
An article comprising:
- a substrate;
- and
- a first distributed coupled-cavity (DCC) reflector disposed on the substrate, the first DCC reflector having a first longitudinal axis and being reflective at a first wavelength, wherein the first DCC reflector includes:
- a first plurality of teeth, wherein the teeth of the first plurality thereof have different lengths along the first longitudinal axis, and wherein each tooth of the first plurality thereof has a first length that is based on its location along the first longitudinal axis;
- and
- a first plurality of gaps, wherein the gaps of the first plurality thereof have different lengths along the first longitudinal axis, and wherein each gap of the first plurality thereof has a second length that is based on its location along the first longitudinal axis;
- wherein the of teeth of the first plurality thereof and the gaps of the first plurality thereof are interleaved and collectively define a first plurality of cavities, each cavity of the first plurality thereof having a reflection peak at the first wavelength.
An article comprising a first distributed coupled-cavity (DCC) reflector disposed on a substrate, the first DCC reflector having a first longitudinal axis and being reflective at a first wavelength, lo, wherein the first DCC reflector includes a first plurality of segments, the first plurality of segments including M segments that are arranged contiguously along the first longitudinal axis, and wherein each mth segment, where m=1 through M, includes:
- a first tooth having a first length, L1,m, along the first longitudinal axis, wherein L1,m=(lo/4n1+b) (4m+1);
- and
- a first gap having a second length, L2,m, along the first longitudinal axis, wherein L2,m=(lo/4n2−b) (4m+3);
- wherein n1 is the effective refractive index of the first tooth, n2 is the effective refractive index of the first gap, and b is a section-detuning value for giving rise to a phase error that accumulates as a multiple of p/4;
- wherein the first plurality of segments defines a first plurality of cavities, each cavity of the first plurality thereof having a reflection peak at the first wavelength.
A method comprising:
- providing a first substrate;
- and
- forming a first distributed coupled-cavity (DCC) reflector on the first substrate, the first DCC reflector being formed such that it has a first longitudinal axis, is reflective at a first wavelength, lo, and includes:
- a first plurality of teeth, wherein the teeth of the first plurality thereof have different lengths along the first longitudinal axis, and wherein each tooth of the first plurality thereof has a first length that is based on its location along the first longitudinal axis;
- and
- a first plurality of gaps, wherein the gaps of the first plurality thereof have different lengths along the first longitudinal axis, and wherein each gap of the first plurality thereof has a second length that is based on its location along the first longitudinal axis;
- wherein the of teeth of the first plurality thereof and the gaps of the first plurality thereof are interleaved and collectively define a first plurality of cavities, each cavity of the first plurality thereof having a reflection peak at the first wavelength.
Dependencies are inferred from the claim text.