MONOLITHIC BROADBAND ENERGY COLLECTOR WITH DICHROIC FILTERS AND MIRRORS EMBEDDED IN WAVEGUIDE
A solar energy collector includes a planar waveguide formed of multiple material layers having at least two different dielectric constants. Two or more dichroic filters disposed within the waveguide core, and two or more minors are also disposed within the waveguide core. At least one optical to electrical detector positioned in alignment with each of the dichroic filters, and at least one optical to electrical detector is aligned with each of the mirrors. The dichroic filter may be formed from a plurality of material layers.
1 . A solar energy collector apparatus comprising:
a planar waveguide having a top surface, a bottom surface, and a core, the core providing a coherent propagation mode via internal reflection along a horizontal propagation axis parallel to the top surface and bottom surface, the waveguide further including multiple material layers having at least two different dielectric constants;
a prism disposed on the top surface of the waveguide and coextensive with the propagation axis of the planar waveguide, for providing electromagnetic energy to the waveguide;
two or more dichroic filters disposed within the waveguide core;
two or more mirrors also disposed within the waveguide core, each of the minors associated with one of the dichroic filters, each minor having a surface disposed at an angle with respect to the horizontal propagation axis of the core, and each of the mirrors disposed in parallel with at least one another minor;
at least one optical to electrical detector positioned aligned with the dichroic filters;
at least one optical to electrical detector aligned with the minors; and
the optical to electrical detectors disposed below the bottom surface of the waveguide.
2 . The apparatus of claim 1 wherein the dichroic filter is formed from a plurality of material layers.
3 . The apparatus of claim 1 wherein the detector aligned with the dichroic filters and the detector aligned with the mirrors are active in two different wavelength ranges.
4 . The apparatus of claim 1 wherein the detectors are each disposed in a same horizontal plane.
5 . The apparatus of claim 1 wherein the detectors are photovoltaics.
6 . The apparatus of claim 1 wherein the detectors are metal-insulator-metal (MIM) detectors.
7 . The apparatus of claim 1 wherein the minors are disposed on a surface etched into the waveguide.
8 . The apparatus of claim 1 wherein the minors are disposed at a critical angle within the waveguide.
9 . The apparatus of claim 1 wherein the detectors are each a continuous material layer disposed adjacent two or more of the respective dichroic filters.
10 . The apparatus of claim 1 wherein the detectors comprise a plurality of discrete detectors, each detector associated with a given one of the dichroic filters.
11 . The apparatus of claim 1 additionally comprising
a coupling layer disposed between the prism and the waveguide and having thickness and dielectric constant to provide evanescent coupling of light energy between the prism and waveguide.
12 . The apparatus of claim 1 wherein the optical detectors further comprise a dual cell photovoltaic.