ENCODING and decoding images
FOCUS
for these proof-of-principle experiments to transition to real-world applications and compete with classical imaging systems. Among the most critical are the limited photon detection efficiency of single-photon sensitive cameras- rarely exceeding 30 %- and the inherent inefficiency of SPDC in generating correlated photons. While these limitations are still manageable when working with two-photon states, the scaling rapidly deteriorates for generating and detecting N-photon states: both photon detection efficiency and conversion probability decrease exponentially with N.
Despite its current limitations, recent progress in quantum imaging is encouraging. Alternative photon sources to SPDC, such as semiconductor quantum dots [ 11 ], are being actively developed and show promise. Simultaneously, event-based cameras with higher quantum efficiency and improved temporal resolution are advancing, often driven by consumer market demands – such as the integration of SPAD cameras in smartphones. As these technologies continue to evolve, quantum imaging remains most relevant for specialized applications, including biological imaging of photo-sensitive samples [ 4 ] and imaging in challenging wavelength ranges [ 12 ].
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