An optical device comprising: an underlying device configured to output light in a first spectrum as a result of absorbing input light; a stacked device, formed in a single semiconductor chip, configured to be coupled in an overlapping fashion to an optical output of the underlying device, the stacked device being transparent, according to a first transmission efficiency, to light in the first spectrum, the stacked device characterized by comprising: a plurality of electro-optical circuits formed on the semiconductor chip, including: a plurality of light emitters (516, 518) configured to output at least one color of light; a plurality of detectors, each detector associated with one or more light emitters (516, 518) in the plurality of light emitters (516, 518), each detector configured to detect light emitted from the underlying device; and wherein the light emitters (516, 518) are configured to output light dependent on light detected by an associated detector; and the optical device further comprising a plurality of optical filters (502, 506, 510) optically coupled to an optical input of the underlying device, wherein each filter (502, 506, 510) in the plurality of optical filters (502, 506, 510) is aligned with a detector from among the plurality of detectors to suppress absorption of certain wavelengths of light by the underlying device thereby affecting light detected by the detectors and thus further affecting the light output by the light emitters (516, 518). an underlying device configured to output light in a first spectrum as a result of absorbing input light; a stacked device, formed in a single semiconductor chip, configured to be coupled in an overlapping fashion to an optical output of the underlying device, the stacked device being transparent, according to a first transmission efficiency, to light in the first spectrum, the stacked device characterized by comprising: a plurality of electro-optical circuits formed on the semiconductor chip, including: a plurality of light emitters (516, 518) configured to output at least one color of light; a plurality of detectors, each detector associated with one or more light emitters (516, 518) in the plurality of light emitters (516, 518), each detector configured to detect light emitted from the underlying device; and wherein the light emitters (516, 518) are configured to output light dependent on light detected by an associated detector; and a plurality of light emitters (516, 518) configured to output at least one color of light; a plurality of detectors, each detector associated with one or more light emitters (516, 518) in the plurality of light emitters (516, 518), each detector configured to detect light emitted from the underlying device; and wherein the light emitters (516, 518) are configured to output light dependent on light detected by an associated detector; and the optical device further comprising a plurality of optical filters (502, 506, 510) optically coupled to an optical input of the underlying device, wherein each filter (502, 506, 510) in the plurality of optical filters (502, 506, 510) is aligned with a detector from among the plurality of detectors to suppress absorption of certain wavelengths of light by the underlying device thereby affecting light detected by the detectors and thus further affecting the light output by the light emitters (516, 518).