100 Hertz frame-rate switching three-dimensional orbital angular momentum multiplexing holography via cross convolution

Abstract

The orbital angular momentum (OAM) of light has been implemented as an information carrier in OAM holography. Holographic information can be multiplexed in theoretical unbounded OAM channels, promoting the applications of optically addressable dynamic display and high-security optical encryption. However, the frame-rate of the dynamic extraction of the information reconstruction process in OAM holography is physically determined by the switching speed of the incident OAM states, which is currently below 30 Hz limited by refreshing rate of the phase-modulation spatial light modulator (SLM). Here, based on a cross convolution with the spatial frequency of the OAM-multiplexing hologram, the spatial frequencies of an elaborately-designed amplitude distribution, namely amplitude decoding key, has been adopted for the extraction of three-dimensional holographic information encoded in a specific OAM information channel. We experimentally demonstrated a dynamic extraction frame rate of 100 Hz from an OAM multiplexing hologram with 10 information channels indicated by individual OAM values from -50 to 50. The new concept of cross convolution theorem can even provide the potential of parallel reproduction and distribution of information encoded in many OAM channels at various positions which boosts the capacity of information processing far beyond the traditional decoding methods. Thus, our results provide a holographic paradigm for high-speed 3D information processing, paving an unprecedented way to achieve the high-capacity short-range optical communication system.

Structured Light Laser Based on Intra-Cavity Modulation

“…However, in fact, particularly in the dynamic transformation of holograms, the relatively low refresh rate of the phase-only SLM always restricts data-handling capacity. Some technologies based on cross-convolution have been put forward to increase the speed of frame rate [58].…”

Broadband Wide Field-of-View Metalens by the Virtual-Diffraction-Aperture Method

“…Recently, various metasurfaces have progressively sprung up as new devices for modulating electromagnetic (EM) fields at subwavelength spatial resolution through patterned elements on a flat surface. − Metalens, a specific case of the metasurface, has emerged as the focusing component of advanced imaging systems and has received growing interest, owing to its subwavelength thickness and diverse functionalities. − Versatile metalens-enabled devices have been designed and realized in an ultra-compact configuration, becoming significant as the demand for high-performance and low-cost miniaturized devices rapidly increases. − The metalens commercialization is, unfortunately, affected by different aberrations, resulting in, for example, deteriorated image resolution and limited field-of-view (FOV). , …”

Meta-optics empowered vector visual cryptography for high security and rapid decryption

“…Nevertheless, the early efforts rely on the complex combination of multiple optical components for signal processing in the Fourier realm 7 , leading to a large form factor. Furthermore, owing to the limited vector optical-field manipulation capabilities of conventional optical devices, the abundant degrees of freedom of light, such as amplitude, phase, frequency, polarization, etc., have not been fully exploited in early optical cryptography, leading to a limited safety performance [8][9][10][11] .In recent years, metasurfaces, one kind of ultrathin optical elements consisting of an array of subwavelength nanostructures, have been developed to manipulate all the fundamental properties of light [12][13][14][15][16][17][18][19][20][21][22][23][24] . By combining multiple meta-atoms [25][26][27] or different phase shift mechanisms [28][29][30][31][32] , a single metasurface can be engineered to achieve independent multi-dimensional optical-field manipulation [33][34][35] .…”

“…In recent years, metasurfaces, one kind of ultrathin optical elements consisting of an array of subwavelength nanostructures, have been developed to manipulate all the fundamental properties of light [12][13][14][15][16][17][18][19][20][21][22][23][24] . By combining multiple meta-atoms [25][26][27] or different phase shift mechanisms [28][29][30][31][32] , a single metasurface can be engineered to achieve independent multi-dimensional optical-field manipulation [33][34][35] .…”