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Polarization manipulation is essential in photonic integrated circuits and has numerous applications in various fields, such as optical communication, nonlinear optics, and quantum optics. Advances in nanofabrication have enabled the integration of subwavelength‐structured metamaterials on optical waveguides, providing unprecedented optical manipulation capabilities beyond classical waveguide‐based architectures. In this paper, the polarization space is demonstrated to be fully manipulated by a dielectric metamaterial composed of nanoholes and nanoslots. This approach offers competitive performances for key polarization components, including the polarizer, polarization beam splitter, and polarization‐splitter‐rotator, while maintaining ultra‐compact coupling regions of 18×1 µm2, 16×1.1 µm2, and 13×1 µm2 respectively. The devices are designed by manipulating the phase and amplitude of all possible eigenmodes supported in the waveguide, which is inherently scalable and versatile for on‐chip mode and wavefront manipulation. The unique properties of metamaterials provide powerful tools for on‐chip polarization manipulation and offer new possibilities for the development of compact and high‐performance photonic integrated circuits. [ABSTRACT FROM AUTHOR]

The emergence of new materials and fabrication techniques provides progress in the development of advanced photonic and communication devices. Transition metal dichalcogenides (e.g., molybdenum disulfide, MoS2) are novel materials possessing unique physical and chemical properties promising for optical applications. In this paper, a metasurface composed of particles made of bulk MoS2 is proposed and numerically studied considering its operation in the near‐infrared range. In the bulk configuration, MoS2 has a layered structure being a uniaxial anisotropic crystal demonstrating an optical birefringence property. It is supposed that the large‐scale and uniform MoS2 layers are synthesized in a vertical‐standing morphology, and then they are patterned into a regular 2D array of disks to form a metasurface. The natural anisotropy of MoS2 is utilized to realize the splitting of electric and magnetic dipole modes of the disks while optimizing their geometric parameters to bring the desired modes into overlap. At the corresponding resonant frequencies, the metasurface behaves as either an electric or a magnetic mirror, depending on the polarization of incident light. Based on the extraordinary reflection characteristics of the proposed metasurface, it can be considered an alternative to traditional mirrors and optical splitters when designing compact and highly efficient metadevices, which provide polarization and phase manipulation of electromagnetic waves on a subwavelength scale. [ABSTRACT FROM AUTHOR]

While the quantum metrological advantages of performing non‐Gaussian operations on two‐mode squeezed vacuum (TMSV) states have been extensively explored, similar studies in the context of two‐mode squeezed thermal (TMST) states are severely lacking. This paper explores the potential advantages of performing non‐Gaussian operations on TMST state for phase estimation using parity detection‐based Mach–Zehnder interferometry and compares it with the TMSV case. To this end, a realistic photon subtraction, addition, and catalysis model is considered. A unified Wigner function of the photon subtracted, photon added, and photon catalyzed TMST state is derived, which is used to obtain the expression for the phase sensitivity. The results show that performing non‐Gaussian operations on TMST states can enhance the phase sensitivity for significant squeezing and transmissivity parameter ranges. Because of the probabilistic nature of these operations, it is of utmost importance to consider their success probability. When the success probability is considered, the photon catalysis operation performed using a high transmissivity beam splitter is the optimal non‐Gaussian operation. This contrasts with the TMSV case, where photon addition is observed as the most optimal. Further, the derived Wigner function of the non‐Gaussian TMST states will be useful for state characterization and various quantum protocols. [ABSTRACT FROM AUTHOR]

The polarization beam splitter (PBS) is a pivotal element in the polarization management of free-space optical instruments and systems. Photonic integrated circuits for sensing, imaging, communications, and quantum-information processing also have needs for monolithically integrated PBSs with an ultra-broad optical bandwidth. In this paper, a novel silicon nanophotonic PBS inspired by the crystalline Glan-Thompson prism but implemented with silicon subwavelength-grating (SWG) metamaterials is presented. Due to the tailored artificial anisotropy of SWGs, the meta-prism functions like a thin-film reflector or a waveguide crossing for different polarizations. Thus, the incident light can be steered with strong polarization selectivity and negligible wavelength dependence. Unlike conventional PBS designs, the routing of polarized light is enabled by the wavelengthindependent total internal reflection in anisotropy-engineered effective media, thereby breaking the bandwidth limit. The device footprint is as small as ≈15 x 7 υm². Low insertion losses of 0.6-1.7 dB and high extinction ratios of 20-30 dB are experimentally achieved spanning a record broad bandwidth of over 415 nm, ranging from 1.26 to 1.675 μm wavelength. These results represent, to the best of their knowledge, the most broadband integrated PBS ever demonstrated to date. [ABSTRACT FROM AUTHOR]

Design of the optical devices is an important matter of discussion in the present scenario where optical devices have become ultra‐compact due to miniaturization, ultra‐speed with the integration of optoelectronic devices. In this paper a 1 × 3 2D photonic crystal based on optical beam‐splitter has been designed on OptiFDTD for TE polarized light. The wafer is of the dimensions of 21 µm × 15 µm in length and width, respectively. The design works at the wavelength of 1.55 µm, and the mode is selected to be the Gaussian Modulated Continuous Wave (GMCW). The design is based on the 2D Hexagonal lattice, where the elliptical Si‐rods are placed in the air. This splitter prototype consists of one input and three outputs with the split ratio as 60:20:20. This refers to the first output port has 60% power of the transmitted signal, and the second and the third output ports have 20% power of the input. The structure is implemented using OptiFDTD software. It utilizes Finite Domain Time Difference (FDTD) numerical method to analyze the transmission spectra of the structure, and the Plane Wave Expansion (PWE) method is utilized to calculate the photonic bandgap of the prototype. [ABSTRACT FROM AUTHOR]

The development of high‐efficiency compact non‐mechanical beam tuning devices has attracted a lot of attention for light detection and ranging, augmented reality display, and chip‐to‐chip communication. Owing to the fast wavefront manipulation in an ultra‐thin dimension, metasurfaces have been regarded as potential substitutes for traditional tunable optical components toward further miniaturization and low power consumption. However, most beam tuning metasurfaces currently are polarization‐sensitive and designed to work in reflection mode, which limit their applications in integrated optical systems for full‐range steering. In this paper, a transmission mode polarization‐insensitive beam switching metasurface based on nonvolatile phase‐change material Ge2Sb2Te5 is proposed and experimentally demonstrated at the telecommunication wavelength. The high transmission efficiency with a large switching angle of up to 75° is achievable for potentially full‐range beam steering applications. As a proof of concept, the transmitted beam with a switching angle of 15° and directivity of 82.4% is demonstrated. In addition, by controlling the phase transition in the intermediate states, the metasurface can be used as a tunable beam splitter to control the ratio of the beam power between two predesigned transmission angles. The demonstrated phase‐change metasurfaces pave the way for achieving high‐efficiency dynamic beam steering for various important applications. [ABSTRACT FROM AUTHOR]