Photonics package with tunable liquid crystal lens
A photonics package that incorporates a liquid crystal lens situated between a light source and a waveguide or output element of the package. The liquid crystal lens may focus or collimate light passing through it. This may be useful, for example, to focus light from a light source on or at an entry of a waveguide. Certain embodiments may include or incorporate routing or optical elements between the light source and the liquid crystal lens, and/or on a side of the lens opposite a side on which the light source is located.
1. A photonic integrated circuit package, comprising:
a substrate;
a light source disposed on the substrate and operable to emit a light output;
a tunable liquid crystal lens disposed on the substrate and comprising:
a first exterior substrate comprising a first electrode conductively coupled to a voltage source;
an interior substrate;
a second exterior substrate comprising a second electrode conductively coupled to at least one of the voltage source or to ground potential;
a first liquid crystal layer interposing the first exterior substrate and the interior substrate; and
a second liquid crystal layer interposing the interior substrate and the second exterior substrate, wherein the tunable liquid crystal lens is operable to switch between:
a base state in which a first voltage is applied by the voltage source across the first electrode and the second electrode; and
a light steering state in which a second voltage is applied by the voltage source across the first electrode and the second electrode;
first optics interposing the light source and the tunable liquid crystal lens, disposed on the substrate, and comprising an optical isolator coupled to the light source and configured to receive light as output by the light source;
an integrated waveguide disposed on the substrate;
second optics interposing the tunable liquid crystal lens and the integrated waveguide and disposed on the substrate, the second optics configured to cooperate with the tunable liquid crystal lens to direct light output from the light source onto an input facet of the integrated waveguide when the tunable liquid crystal lens is in the base state; and
an integrated sensor disposed on the substrate and configured to determine an operating parameter of the photonic integrated circuit package, the operating parameter comprising at least one of a temperature of the photonic integrated circuit package or a coupling efficiency between the light source and the photonic integrated circuit package, the integrated sensor configured to cooperate with the voltage source to transition the tunable liquid crystal lens to the light steering state from the base state by varying the second voltage in response to each determination of the operating parameter satisfying a threshold.
2. The photonic integrated circuit package of claim 1 , wherein the operating parameter satisfying the threshold indicates a misalignment of the second optics and the integrated waveguide.
3. The photonic integrated circuit package of claim 2 , wherein the tunable liquid crystal lens is one of multiple tunable liquid crystal lenses.
4. The photonic integrated circuit package of claim 1 , wherein
each of the first exterior substrate, the second exterior substrate, the substrate, the first electrode, and the second electrode are transparent to wavelengths of the light output.
5. The photonic integrated circuit package of claim 1 , wherein the tunable liquid crystal lens is variably tunable, such that the tunable liquid crystal lens may increase steering of the light output as the second voltage varies.
6. The photonic integrated circuit package of claim 1 , wherein the tunable liquid crystal lens is dynamically tunable, such that the tunable liquid crystal lens steers the light output in response to a change in the operating parameter of the photonic integrated circuit package.
7. The photonic integrated circuit package of claim 6 , wherein the operating parameter is the temperature of the photonic integrated circuit package.
8. The photonic integrated circuit package of claim 6 , wherein the tunable liquid crystal lens is both dynamically tunable and variably tunable.
9. The photonic integrated circuit package of claim 1 , further comprising an index-matching material positioned between the tunable liquid crystal lens and either or both of the first optics and the second optics.
10. The photonic integrated circuit package of claim 1 , wherein detection of changes in the operating parameter of the photonic integrated circuit package occurs while the light source is emitting light.