Vertical cavity surface-emitting lasers (VCSELs) have made indispensable contributions to the development of modern optoelectronic technologies. However, arbitrary beam shaping of VCSELs within a ...compact system has remained inaccessible until now. The emerging ultra-thin flat optical structures, namely metasurfaces, offer a powerful technique to manipulate electromagnetic fields with subwavelength spatial resolution. Here, we show that the monolithic integration of dielectric metasurfaces with VCSELs enables remarkable arbitrary control of the laser beam profiles, including self-collimation, Bessel and Vortex lasers, with high efficiency. Such wafer-level integration of metasurface through VCSEL-compatible technology simplifies the assembling process and preserves the high performance of the VCSELs. We envision that our approach can be implemented in various wide-field applications, such as optical fibre communications, laser printing, smartphones, optical sensing, face recognition, directional displays and ultra-compact light detection and ranging (LiDAR).
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Polarization response of artificially structured nano-antennas can be exploited to design innovative optical components, also dubbed "vectorial metasurfaces", for the modulation of phase, amplitude, ...and polarization with subwavelength spatial resolution. Recent efforts in conceiving Jones matrix formalism led to the advancement of vectorial metasurfaces to independently manipulate any arbitrary phase function of orthogonal polarization states. Here, we are taking advantages of this formalism to design and experimentally validate the performance of CMOS compatible Jones matrix metasurfaces monolithically integrated with standard VCSELs for on-chip spin-decoupling and phase shaping. Our approach enables accessing the optical spin states of VCSELs in an ultra-compact way with previously unattainable phase controllability. By exploiting spin states as a new degree of freedom for laser wavefront engineering, our platform is capable of operating and reading-out the spin-momentum of lasers associated with injected spin carriers, which would potentially play a pivotal role for the development of emerging spin-optoelectronic devices.
Metasurfaces offer complete control of optical wavefront at the subwavelength scale, advancing a new class of artificial planar optics, including lenses, waveplates, and holograms, with unprecedented ...merits over conventional optical components. In particular, the ultrathin, flat, and compact characteristics of metasurfaces facilitate their integration with semiconductor devices for the development of miniaturized and multifunctional optoelectronic systems. In this work, generation of structured light is implemented at an ultracompact wafer‐level through the monolithic integration of metasurface with standard vertical cavity surface‐emitting lasers (VCSELs). This work opens new perspectives for the design of structured light systems with compactness, lightweight, and scalability. Ultracompact beam structured laser chips with versatile functionalities are experimentally demonstrated, including multichannel beams array generation, on‐chip large‐angle beam steering up to 60°, and wafer‐level holographic beam shaping with a wide field of view (about 124°). The results will promote the development of compact light structuring systems with great potential in 3D imaging, displays, robotic vision, human–computer interaction, and augmented/virtual reality.
On‐chip generation of structured light is demonstrated via monolithic integration of dielectric metasurfaces with standard vertical cavity surface‐emitting lasers (VCSELs). This new type of ultracompact beam structuring chip exhibits versatile functionalities, including multichannel beams array generation, on‐chip large‐angle beam steering up to 60°, and wafer‐level holographic beam shaping with a wide field of view.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Metasurface polarization optics that consist of 2D array of birefringent nano‐antennas have proven remarkable capabilities to generate and manipulate vectorial fields with subwavelength resolution ...and high efficiency. Integrating this new type of metasurface with the standard vertical cavity surface‐emitting laser (VCSEL) platform enables an ultracompact and powerful solution to control both phase and polarization properties of the laser on a chip, which allows to structure a VCSEL into vector beams with on‐demand wavefronts. Here, this concept is demonstrated by directly generating versatile vector beams from commercially available VCSELs through on‐chip integration of high‐index dielectric metasurfaces. Experimentally, the versatility of the approach for the development of vectorial VCSELs are validated by implementing a variety of functionalities, including directional emission of multibeam with specified polarizations, vectorial holographic display, and vector vortex beams generations. Notably, the proposed vectorial VCSELs integrated with a single layer of beam shaping metasurface bypass the requirements of multiple cascaded optical components, and thus have the potential to promote the advancements of ultracompact, lightweight, and scalable vector beams sources, enriching and expanding the applications of VCSELs in optical communications, laser manipulation and processing, information encryption, and quantum optics.
On‐chip generation and manipulation of vector beams are demonstrated by monolithically integrating vectorial metasurfaces with standard vertical cavity surface‐emitting lasers (VCSELs). The developed approach enables a powerful tool to structure the complex wavefronts of a VCSEL in an ultracompact way, providing the access to previously unattainable both phase and polarization degrees of freedom.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Blockchain technology has been widely applied in numerous industries with its decentralization, verifiability, distributivity, and immutability. However, the identity privacy security of blockchain ...users is facing serious threats because of the openness of traditional blockchain transaction information. Moreover, numerous traditional cryptographic algorithms used by blockchain transaction networks are difficult to attack quantum computing. In this paper, we propose a new lattice-based blind ring signature scheme in allusion to completely anonymous blockchain transaction systems. There into, the blind ring signature can implement the complete anonymity of user identity privacy in blockchain transactions. Meanwhile, lattice cryptography can availably resist quantum computing attacks. Firstly, the proposed signature scheme has strong computational security based on the small integer solution (SIS) problem and a high sampling success rate by utilizing the techniques of rejection sampling from bimodal Gaussian distribution. Secondly, the proposed signature scheme can satisfy the correctness and security under the random oracle model, including anonymity, blindness, and one-more unforgeability. Thirdly, we construct a blockchain transaction system based on the proposed blind ring signature algorithm, which realizes the completely anonymous and antiquantum computing security of the blockchain users’ identity privacy. Finally, the performance evaluation results show that our proposed blind ring signature scheme has lower latency, smaller key size, and signature size than other similar schemes.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract Metasurface enables a new class of “meta‐optics” that can manipulate light at subwavelength scale. Despite that versatile metasurfaces have been demonstrated based on a wide range of ...materials, the vulnerability of conventional materials to harsh environments, i.e., low resistance to corrosion, low transparency at short wavelength, and lack of thermal/mechanical stability, greatly limit their applications in extreme conditions. Diamond is well‐known for exceptional properties, including the highest thermal conductivity, high damage resistance, extraordinary hardness, and chemical inertness. Therefore, diamond based metasurface is generally expected to benefit from its material merits for extreme use. However, the performance of diamond metasurface in harsh environments remains unexplored up to date. To address this question, this work is designed to study the suitability of single‐crystal diamond based metasurface for broadband applications under harsh environments. As an example, diamond metasurfaces with representative functionalities, including holographic wavefront‐shaping, DUV‐focusing, are investigated under high‐temperature, acid/alkali, and abrasive conditions, respectively. The findings prove the capability of diamond metasurfaces for applications in broadband and harsh conditions, which not only provides a practical and scalable scheme to encode on‐demand functionalities into diamond, but also unlocks a capable candidate to develop robust, large bandwidth, and durable meta‐optics for advanced wavefront shaping under extreme conditions.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The orthogonality among optical beams with different orbital angular momentum (OAM) modes presents a new perspective as independent data‐carrying channels for multiplexing and demultiplexing. In ...particular, the theoretically infinite topological charge of OAM beam promises the unbounded capacity in communication systems. As a key part for the advancement of OAM technologies, OAM source has attracted considerable interest and experienced a rapid development. Nevertheless, conventional approaches to create OAM modes mainly rely on the use of bulky optical devices and external laser source, preventing their implementation into a miniaturized system. As a contrast, on‐chip generation of OAM beams with a built‐in source stands out with several advantages, including small footprint, compactness, portability, and high‐power efficiency. In this work, a versatile approach to directly produce OAM modes with on‐demand characteristics on a chip is demonstrated. Featuring the judicious combination of the emerging dielectric metasurface with the standard vertical cavity surface‐emitting laser (VCSEL) platform, the approach represents a feasible solution to the wide implementation of wafer‐level OAM emitters for optoelectronic integrations. Prototype laser chips for the generation of both individual OAM beam and OAM array with novel functionalites, such as controllable directionality and spatially varying topological charge and distribution, are systematically presented.
Wafer‐level optical vortex sources are demonstrated via monolithic integration of metasurfaces with vertical cavity surface‐emitting lasers (VCSELs). This approach features versatile capabilities to on‐chip convert the Gaussian beam of a VCSEL into any given orbit angular mode (OAM) with on‐demand characteristics, including multichannel generation and well‐defined directionality.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Two-dimensional coherently coupled arrays of vertical cavity surface emitting lasers were fabricated using proton implantation. A 2 × 2 array with the far field beamwidth of 3.6° ( 1.18×diffraction ...limited), the output power of 0.45 mW, and the spectral line width of 0.2 nm was achieved for continuous wave operation at room temperature. It showed an excellent beam quality due to the in-phase coupling among the elements in the array. The array performance dependence on injection current level and thermal effects was discussed. The processing for the arrays is considerably simple and can be used as an alternative to other array implementations.
A three-dimensional electrical-thermal coupling model based on the finite element method is applied to study thermal properties of implant-defined vertical cavity surface emitting laser （VCSEL） ...arrays. Several parameters including inter-element spacing, scales, injected current density and substrate temperature are considered. The actual temperatures obtained through experiment are in excellent agreement with the calculated results, which proves the accuracy of the model. Due to the serious thermal problem, it is essential to design arrays of low self-heating. The analysis can provide a foundation for designing VCSEL arrays in the future.
An optimization of oxide aperture diameter to match the light emission aperture (the central defect region) in the photonic crystal vertical-cavity surface-emitting laser (PhC-VCSEL) is presented in ...order to obtain low threshold current and high single-fundamental-mode output of the device. A 3-D finite-difference time-domain method has been applied to simulate the mode field distribution and quality factors (Q factors) of fundamental and high order transverse modes which correspond to the mode loss of the PhC-VCSEL cavity. Single-fundamental-mode operation of PhC-VCSEL with 1.7-mW output power and low threshold current of 0.7-mA is demonstrated after oxide aperture optimization.
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