Harnessing disordered photonics via multi-task learning towards intelligent four-dimensional light field sensors

Abstract

The complete description of a continuous-wave light field includes its four fundamental properties: wavelength, polarization, phase and amplitude. However, the simultaneous measurement of a multi-dimensional light field of such four degrees of freedom is challenging in conventional optical systems requiring a cascade of dispersive and polarization elements. In this work, we demonstrate a disordered-photonics-assisted intelligent four-dimensional light field sensor. This is achieved by discovering that the speckle patterns, generated from light scattering in a disordered medium, are intrinsically sensitive to a high-dimension light field given their high structural degrees of freedom. Further, the multi-task-learning deep neural network is leveraged to process the single-shot light-field-encoded speckle images free from any prior knowledge of the complex disordered structures and realizes the high-accuracy recognition of full-Stokes vector, multiple orbital angular momentum (OAM), wavelength and power. The proof-of-concept study shows that the states space of four-dimensional light field spanning as high as 1680=4 (multiple-OAM) $$\times$$ × 2 (OAM power spectra) $$\times$$ × 15 (multiple-wavelength) $$\times$$ × 14 (polarizations) can be well recognized with high accuracy in the chip-integrated sensor. Our work provides a novel paradigm for the design of optical sensors for high-dimension light fields, which can be widely applied in optical communication, holography, and imaging.

Achromatic CMOS-Integrated Four-Bit Orbital Angular Momentum Mode Detector at Three Wavelengths

“…The quickly increasing data transfer load requires revolutionary breakthroughs in current optoelectronic systems. , Remarkably, the ever-increasing demand for high-capacity optical devices has prompted the use of orthogonal physical dimensions of light for optical multiplexing to process information in parallel. − In recent years, orbital angular momentum (OAM), represented by a helical wavefront, exp­(i lφ ) (where l and φ denote the helical mode index and the azimuthal angle, respectively), − has emerged as a new degree of freedom of light for boosting information capacity due to its theoretically unbounded helical mode index. − The orthogonal OAM mode states can be utilized as an information carrier, creating the pioneering concepts such as high-security encryption holography, optically addressable three-dimensional (3D) display, high-capacity optical communication, − six-dimensional data storage, and high-dimensional quantum entanglement. , To further increase the number of information channels in practical applications, the synergistic multiplexing of OAM and other physical dimensions has attracted a significant amount of attention. , For example, the light beams with distinctive spin eigenstates and OAM states can be individually controlled in a high-security nested holographic encryption scheme; the 3D optical elements encoded with color and OAM information substantially increase the number of combinations for optical anticounterfeiting and photonic lock–key devices in a pairwise fashion, and the merging of the wavelength and OAM contributes to a total data capacity on the order of Pbit per second in the field of optical communications . Among these technologies, manipulating the multidimensional light fields with compact devices is critical.…”

“…T he quickly increasing data transfer load requires revolutionary breakthroughs in current optoelectronic systems. 1,2 Remarkably, the ever-increasing demand for highcapacity optical devices has prompted the use of orthogonal physical dimensions of light for optical multiplexing to process information in parallel. 3−6 In recent years, orbital angular momentum (OAM), represented by a helical wavefront, exp(ilφ) (where l and φ denote the helical mode index and the azimuthal angle, respectively), 7−10 has emerged as a new degree of freedom of light for boosting information capacity due to its theoretically unbounded helical mode index.…”