Luminescent detector for free-space optical communication

A method comprising, by a luminescent detector:

• receiving, at a first side of a wavelength-shifting element of the luminescent detector, an input-light data signal comprising a first range of wavelengths, wherein the wavelength-shifting element comprises a photoluminescent wavelength-shifting material;
• absorbing, by the photoluminescent wavelength-shifting material, at least a portion of the received input-light data signal;
• producing, by the photoluminescent wavelength-shifting material, an emitted-light data signal comprising a second range of wavelengths, wherein the emitted-light data signal is produced based on an upper-state lifetime of the photoluminescent wavelength-shifting material, and wherein the emitted-light data signal is emitted through a second side of the wavelength-shifting element that is opposite to the first side;
• receiving, by a plasmonic grating of the luminescent detector, at least a portion of the emitted-light data signal, the plasmonic grating comprising a plurality of plasmonic-structure elements;
• directing, by the plasmonic grating, the received portion of the emitted-light data signal toward a photodetector of the luminescent detector;
• receiving, by the photodetector, the directed portion of the emitted-light data signal;
• and
• producing, by the photodetector, an electrical current corresponding to the directed portion of the emitted-light data signal.

An apparatus comprising:

• means for receiving, at a first side of a wavelength-shifting element, an input-light data signal comprising a first range of wavelengths, wherein the wavelength-shifting element comprises a photoluminescent wavelength-shifting material;
• means for absorbing, by the photoluminescent wavelength-shifting material, at least a portion of the received input-light data signal;
• means for producing, by the photoluminescent wavelength-shifting material, an emitted-light data signal comprising a second range of wavelengths, wherein the emitted-light data signal is produced based on an upper-state lifetime of the photoluminescent wavelength-shifting material, and wherein the emitted-light data signal is emitted through a second side of the wavelength-shifting element that is opposite to the first side;
• means for receiving, by a plasmonic grating, at least a portion of the emitted-light data signal, the plasmonic grating comprising a plurality of plasmonic-structure elements;
• means for directing, by the plasmonic grating, the received portion of the emitted-light data signal toward a photodetector;
• means for receiving, by the photodetector, the directed portion of the emitted-light data signal;
• and
• means for producing, by the photodetector, an electrical current corresponding to the directed portion of the emitted-light data signal.