Pyroelectric Photodetector Reaches Gigahertz Speeds

As metasurfaces trap and localize optical energy, thermal photodetection begins operating at response times measured in picoseconds rather than conventional slow thermal scales.

Electrical engineers at Duke University have demonstrated a pyroelectric photodetector operating at speeds far beyond those typically associated with thermal detection technologies. The ultrathin device detects light by responding to heat generated when incoming radiation is absorbed, enabling it to capture signals across a wide portion of the electromagnetic spectrum.

Photodetectors form the sensing foundation of modern imaging systems. Conventional semiconductor detectors generate electrical currents when struck by visible light, allowing computers to convert optical signals into digital images. However, semiconductor materials function effectively only within a limited range of wavelengths, restricting their ability to capture information beyond the visible spectrum.

Thermal photodetectors provide an alternative approach. Instead of relying on semiconductor bandgaps, these devices generate electrical signals when absorbed light produces heat within the sensing layer. This mechanism allows them to respond to a broader set of frequencies, but traditional designs have often been slower and bulkier because producing measurable heat typically requires thicker absorbers or intense light sources.