Search

In this paper, a reflective trapezoidal dual-functional beam splitter grating is proposed, which performs two independent functions at 1550 nm. For TE polarization, the grating can achieve a uniform three-port output with efficiencies of 32.85%, 32.89%, and 32.75% for 0th, -1st, and -2nd orders respectively. For TM polarization, the grating can achieve a highly-efficient single-channel output of order -2nd with an efficiency of 93.27%. HfO 2 is chosen as the material of grating ridge layer, the structural parameters of the grating are studied by using rigorous coupled-wave analysis (RCWA) and simulated annealing algorithm (SAA), and the results are verified by using finite element method (FEM). In addition, the influence of structure and incident error on grating efficiency was also analyzed, the results indicate that the grating has good incident bandwidth and manufacturing tolerance with excellent performance. • Trapezoidal dual-functional splitter with two reflective independent functions. • For TE polarization, a uniform three-port with efficiencies of 32.85%, 32.89%, and 32.75% for 0th, -1st, and -2nd orders. • For TM polarization, a highly-efficient single-channel output of order -2nd with an efficiency of 93.27%. [ABSTRACT FROM AUTHOR]

The spin part of the angular momentum of light can cause a birefringent particle to spin around its axis, while having no effect on a nonbirefringent particle. The orbital part of light’s angular momentum, on the other hand, can cause both birefringent and nonbirefringent particles to orbit around the axis of a light beam. In this paper, we demonstrate that nonbirefringent particles can also be made to spin around their axis when trapped in an optical vortex beam. The rotation of the particle depends on the ratio of the size of the particle and the diameter of the laser beam in which the particle is trapped. It can therefore be controlled by varying the position of the particle with respect to the focal point of the laser beam. The rotational frequency can also be controlled by changing the polarization state of the beam, since spin–orbit coupling affects the total angular momentum experienced by the trapped particle. The motion of the trapped particle is detected by a photodiode and a high-speed camera. Most microparticles found in nature are nonbirefringent, and the method presented in this paper will therefore open up new applications for optically induced rotations. [ABSTRACT FROM AUTHOR]

Metasurface, with its powerful and flexible terahertz(THz) wave manipulation capability, has become a key component of beamforming and imaging systems in the THz band. However, its practical application is limited by fixed properties and propagation mode on a single metasurface. In this paper, we propose a coding metasurface with tunable characteristics and bidirectional working modes. The complete 2π phase compensation can be realized by rotating the InSb unit according to the Pancharatnam-Berry phase concept, and eight meta-atoms are selected to regulate the wavefront of terahertz waves using phase compensation. By increasing the temperature of the InSb from 290 K to 370 K, the working frequency permits wideband coverage from 1.7 to 4.5 THz. As the temperature reaches 341.15 K, which is required for vanadium dioxide's(VO 2) phase transition, the metasurface's propagation direction mode will switch from transmission to reflection. The proposed metasurface can perform beam deflecting, splitting, and focusing functions when VO 2 is in a dielectric state. Meanwhile, beam deflecting, splitting, and radar scattering surface (RCS) reduction can also be achieved when VO 2 is in a metallic state. Furthermore, a near-field image of the letter P is presented as verification. Numerous potential applications for the reconfigurable metasurfaces include polarization beam splitters, imaging, and terahertz switching. • Multi-function. The metalens achieves focusing and RCS attenuation. • Multi-mode. Every metasurface operates in both reflecting and transmissive modes. • Broadband. Metasurface makes advantage of InSb to broaden the operational range. [ABSTRACT FROM AUTHOR]

In this paper, an octagon structure dual-core photonic crystal fiber (OS-DC-PCF) polarization beam splitter (PBS) with a liquid crystal filled central hole is designed. The octagon lattice structure is simple and easy to fabricate. By filling the nematic liquid crystal into the central hole, the birefringence of the octagon structure can be enhanced, and the coupling lengths along the two polarization directions can be reduced. The full vector-finite element method is used to analyze the polarization and coupling characteristics, and the influences of different structural parameters on the extinction ratio (ER) of the PBS. The simulation results show that for the designed OS-DC-PCF PBS, the maximum ER is ∼ 91 dB, the splitting length is only 125 μ m , and the working bandwidth is up to 339 nm (1.493–1. 832 μ m), covering the whole C + L + U communication bands. Moreover, it has good fabrication tolerances and anti-interference ability. It is believed that the designed OS-DC-PCF PBS can provide the critical device support for the future all-optical communication systems. • The proposed dual-core photonic crystal fiber is filled with nematic liquid crystal for splitting. • All holes in the structure are arranged in an octagon lattice, which is easy to fabricate. • The proposed dual-core photonic crystal fiber polarization beam splitter has good beam splitting characteristics. • The proposed dual-core photonic crystal fiber has good fabrication tolerances and anti-interference ability. [ABSTRACT FROM AUTHOR]

In this paper, we construct the input–output relationships of a three-mode nonlinear beam splitter (TNBS) mathematically, and a set of special solutions for the input–output equations are given. By combining two TNBSs and a phase shifter, we propose a scheme for a three-mode nonlinear interferometer (TNI) and give the input–output expression of the whole TNI. Then, we study the phase sensitivity of the TNI by giving input states and detection scheme. In addition, we also calculate the phase sensitivity of a Mach–Zehnder interferometer (MZI), SU(1,1) interferometer (SU(1,1)I) and modified Mach–Zehnder interferometer (MMZI), and we discuss the relationships of phase sensitivity between the MZI, SU(1,1)I, MMZI and TNI. Finally, in the presence of photon losses, we discuss the phase sensitivity of the four different interferometers and make detailed comparisons. It is shown that the TNI has the best robustness against photon losses under certain conditions with the same parameters. [ABSTRACT FROM AUTHOR]

To achieve non-mechanical laser beam steering in the scenario of long distance propagation such as free-space laser communication between satellites, large aperture size is an inevitable issue to be considered to narrow the divergence angle of the output beam. Liquid crystal optical phased array, to be one of the solutions of non-mechanical beam steering, has already shown its obvious potential to achieve a relative large aperture on the order of centimeter. To achieve even larger, its driving matrix becomes squared larger. In this paper, we proposed a novel architecture to realize an optical phased array with a scalable aperture. Meanwhile the driving matrix is almost not increased. It provides the feature of a cascade system with a device of spatial phased modulation and an array of duplicating units. Each unit of the duplicating array is consist of a polarization beam splitter and a half wave plate to have the same output optical field distribution as the input beam whose phase front is modulated by a small size spatial modulator. Not only the property of beam deflection is numerically simulated and experimentally verified, but also the property of divergence angle compression and grating lobes limitation are evaluated. Meanwhile, due to the high precision of the experimental alignment, the non-mechanical beam deflection property is still maintained no matter how many the duplicated unit number is. The relative standard derivation steering error is 0.025. [ABSTRACT FROM AUTHOR]

In this paper, we consider an underwater wireless optical communication (UWOC) system which consists of an M -ary pulse position modulated (PPM) Gaussian optical beam at the transmitter and an avalanche photodiode (APD) at the receiver. In strong oceanic turbulence, we aimed at investigating the system performance in terms of bit error rate (BER) by the help of gamma–gamma channel model. For this purpose, the average power and the aperture averaged scintillation at the finite sized detector are derived by using the extended Huygens–Fresnel principle and the asymptotic Rytov theory, respectively. BER variations are examined versus the average APD gain, modulation order, bit rate as well as the oceanic turbulence parameters, i.e., the rate of dissipation of kinetic energy per unit mass of fluid, the rate of dissipation of mean-squared temperature and the ratio of temperature to salinity contributions to the refractive index spectrum. [ABSTRACT FROM AUTHOR]

In this paper, we report a prism with two liquid–liquid interfaces based on electrowetting effect. The prism is filled with two immiscible liquids which form two liquid–liquid interfaces. In the device, the filling liquids from the top to the bottom are conductive liquid, oil and conductive liquid. The shape of the two liquid–liquid interfaces will be changed when different voltages are applied to the opposite sidewalls. Our device is capable of wide-angle beam steering and the function of light beam translational. Our results show that the light beam can be deflected by ∼ 22 . 3 ° ( − 11 . 5 ° to + 10 . 8 ° ) and the translational distance is 3.1 mm (−1.5 mm to +1.6 mm). The proposed prism has a wide application in light detection, telecommunications, light alignment and other industrial applications. [ABSTRACT FROM AUTHOR]

An ultra-bandwidth and single-mode polarization beam splitter (PBS) of dual hollow-core anti-resonant fiber (DHC-ARF) with circular outer tubes and inner tubes is proposed. Four outer tubes are introduced in the horizontal direction to obtain two hollow cores. The modal coupling is realized through the gap between the two hollow cores. The inner tubes also are inserted into two the outer tubes between the two hollow cores for realizing ultrawide bandwidth in DHC-ARF. To achieve single-mode performance, the high-order modes are coupled with the cladding modes by optimizing the diameter of outer tubes and the inner tubes. The calculation results show that an 11.0 cm long DHC-ARF can be used to develop a PBS with an operating bandwidth of 410 nm, where the polarization extinction ratio is lower than −20 dB. The high-order mode extinction ratio is 625.41, and the loss of fundamental mode is below 1.018 dB/m. • Because the size of elliptical tubes is hard to fabricate, an ultra-bandwidth and single-mode PBS of DHC-ARF completely composed of circular cladding tubes and nested tubes is proposed in the structures. • The influence factors related to bandwidth, the high-order mode extinction ratio and coupling length of PBS based on DHC-ARF are systematically studied by a full-vector finite element method. • The propagation process of light in the optical fiber is also simulated by the light speed propagation method. When the light travels to a certain distance, the two polarized lights will be separated. • Numerical simulation shows an 11.0 cm long DHC-ARF can be used to develop a PBS with an operating bandwidth of 410 nm ranging from 1.35 to 1. 76 μ m , where the polarization extinction ratio reaches −39.0 dB, the high-order mode extinction ratio is 625.41. • The PBS based on DHC-ARF with circular cladding tubes and nested tubes proposed in this paper compares the performance with other existing PBS, this PBS has the widest bandwidth. [ABSTRACT FROM AUTHOR]

One of the technically challenging issues of free-space optical communication systems is the mitigation of angle-of-arrival (AoA) fluctuations, mainly arising from the vibration of receiving end and atmospheric turbulence. A common approach is to employ an AoA tracking system at the receiver. Beacon-based AoA tracking requires the beacon light, thus the system could be complicated and bulky when implemented. Beaconless AoA tracking could help to minimize the optical components required. This tracking typically requires an optical beam splitter to direct the received optical signal both to the beam position sensor and data photo-detector (PD). However, the presence of beam splitter results in optical power loss and tracking imprecision. In this paper, we propose a design of AoA tracking system based on an integrated beam positioning sensor and data PD to obviate the need for beacon light and beam splitter. We carry out a proof-of-concept experimental demonstration of AoA tracking systems for a 10-Gb/s free-space optical link over 104 m, comparing its performance with that of the conventional system. The demonstration shows a loss reduction of >2.9 dB by using the proposed design. It also shows that the proposed design improves the tolerance to AoA fluctuation by more than a factor of 2 at a target bit-error ratio of 10−3. The tracking time is measured to be 171 ms at an AoA fluctuation of 250 μ rad. We show that the loop controller and fast steering mirror bandwidths are the main factors limiting the tracking time. [ABSTRACT FROM AUTHOR]

In this paper, a novel high-sensitivity strain sensor based on Mach-Zehnder interference is drawn up and implemented. A single-mode fiber (SMF)-splitter-PCF-combiner-SMF structure is required for the sensor. The beam splitter and beam combiner, for example, have both used MMF and an air spherical cavity, respectively. When the symmetric structure of the air spherical cavity is utilized, the strain sensor has a maximum sensitivity of −8.15 pm/ μ ɛ. The device has the benefits of high sensitivity, small size, and good repeatability, making it a possible application in strain shift measurement. [ABSTRACT FROM AUTHOR]

Squeezed state of light is one of the important subjects in quantum optics which is generated by optical nonlinear interactions. In this paper, we especially focus on qubit like entangled squeezed states (ESS's) generated by beam splitters, phase-shifter and cross Kerr nonlinearity. Moreover the Wigner function of two-mode qubit and qutrit like ESS are investigated. We will show that the distances of peaks of Wigner functions for two-mode ESS are entanglement sensitive and can be a witness for entanglement. Like the qubit cases, monogamy inequality is fulfilled for qutrit like ESS. These trends are compared with those obtained for qubit and qutrit like entangled coherent states (ECS). [ABSTRACT FROM AUTHOR]

Polarization rotating beam splitter (PSR) is a key component of an on-chip polarization diversity system. However, a conventional PSR is usually designed for a specific use case, which limits general-purpose applications since its polarization rotation and beam splitting ratio are fixed. In this paper, this theoretical modeling, numerical simulations, and experimental results on the reconfigurable PSR with arbitrary beam splitting ratio is proposed for the silicon on insulator (SOI) platform. The device includes a polarization rotation region and a beam splitting region. The polarization rotation region is composed of multi-segment tapered waveguides, and the beam splitting region consists of a racetrack resonator with a heater. By changing the voltage applied to the heater, the beam splitting ratio can be changed. Measured results show that when the incident light is TM 0 mode, it will be converted to TE 0 mode and output from two output ports. The beam splitting ratio of the two output ports can be adjusted from 9:1 to 1:9. Furthermore, in order to optimize the thermal tunability of the PSR, we introduce an asymmetric embedded racetrack resonator with electromagnetically induced transparency (EIT)- like effect in beam splitting region, which can reduce the power consumption dramatically from 27.5 mW to 1.8 mW. The proposed integrated PSR suggests great potential for reconfigurable, fully programmable photonic polarization diversity circuits. In addition, we believe such an embedded racetrack resonator with EIT-like effect could find its applications in chip-scale sensor, modulator, switch, etc. • In this paper, we propose a reconfigurable PSR with arbitrary beam splitting ratio based on silicon on insulator (SOI) ridge waveguides. • The working principle of the asymmetric embedded racetrack resonator with electromagnetically induced transparency (EIT)- like effect has been analytically established and calculated by using temporal coupled mode theory. • The measured results verify that the quality factor of micro-ring resonance can be increased 10 times by introducing the asymmetric embedded racetrack resonator. [ABSTRACT FROM AUTHOR]

A novel heterogeneous structure of two-dimensional photonic crystal polarization beam splitter is proposed, which is similar to the structure of graphene. Research and analysis in this paper are combined with the FDTD method. The results show that, the extinction ratio of the TE and TM output ports can reach over 95 dB and 60 dB respectively. The transmission efficiency for multiple normalized frequencies in the range from 0.3904 ωa /2 πc to 0.4199 ωa /2 πc are within −3 dB. When the normalized frequency is 0.4112 ωa /2 πc , the transmission efficiency is −0.13 dB and the extinction ratio is 31.76 dB at the TM output port, the transmission efficiency is −0.04 dB and the extinction ratio is 80.54 dB at the TE output port. This polarization beam splitter has not only high transmission efficiency, but also ultrahigh extinction ratio. These features have important application prospects in integrated optical circuit, optical communication and other fields. [ABSTRACT FROM AUTHOR]

Photonic crystals have a great prospect in the field of integrated optics due to their high integration and low transmission loss. In this paper, a beam splitter based on the bandgap of photonic crystal is designed and demonstrated experimentally for polarization-dependent beam splitting. The simulated radiation patterns show excellent polarization purity, with a cross-polarization level above 20 dB. Furthermore, the angle deviation of the incident and the temperature change of device have slight impact on beamsplitting. Larger shifting range of incident wavelength is allowed. What is more, the range of medium radius with good splitting effect is relatively large, which reduces the difficulty of production and processing. [ABSTRACT FROM AUTHOR]

A novel ultrahigh birefringence dual-core tellurite glass photonic crystal fiber is designed in this paper. We analyze the charateristics of birefringence and coulpling at the two communication windows by using the finite element method. Compared to the traditional silica materials, the birefringence of dual-core telllurite glass photonic crystal fiber is easier to achieve the order of 10 −2 by adjusting the diameters of four small air holes. Numerical results show the extinction ratio at the wavethlengths of 1.33 μ m and 1.55 μ m can reach −89.97 dB and −81.0 dB and the bandwidths as the extinction ratio better than −10 dB are about 15.1 nm and 13.0 nm, respectively. Our study suggests that a 48.642-mm-long or 14.662-mm-long fiber is new possibility for applications on polarization beam splitter. [ABSTRACT FROM AUTHOR]

A polarization-independent highly-efficient transmission beam splitter based on the cross-shaped ridge structure is proposed in this paper. Based on the rigorous coupled-wave analysis (RCWA) and the simulated annealing (SA) algorithm, the efficiencies of 32.33% of 0th order and 32.42% of ± 1st order for transverse electric (TE) polarization and 32.53% of 0th order and 32.60% of ± 1st order for transverse magnetic (TM) polarization can be achieved. In addition, the simplified modal method (SMM) is applied to analysis the internal energy changes process in detail. What is more, different from the reported references only considering the case of one layer, we also used the SMM to analyze the three-port cross-array beam splitter under normal incidence with the approximation treatment. The results show that the method of which has certain reference value, which can be the guidance of the design of the gratings with similar structures in the future. • A polarization-independent splitter by the cross-shaped ridge structure • Efficiencies 32.33% of 0th order and 32.42% of ±1st order for TE polarization. • Efficiencies 32.53% of 0th order and 32.60% of ±1st order for TM polarization. • Three vector theories of RCWA, SA and SMM applied to the analyzation. [ABSTRACT FROM AUTHOR]

In this paper, an asymmetric directional coupler (DC) based on a GaAs–CaF 2 hybrid plasmonic waveguide (HPW) and a GaAs nanowire (NW) is designed for the mid-infrared polarization beam splitter (PBS). The mode characteristics of the GaAs–CaF 2 HPW and GaAs NW-based PBS are simulated by using the finite element method (FEM). With the appropriate widths of the HPW and NW, the TE polarization mode in the HPW and NW is phase-matched, whereas the TM polarization mode is phase mismatch. Hence, the TE mode undergoes a strong coupling to the GaAs NW while the TM mode pass through the GaAs–CaF 2 HPW directly. The results show that the PBS achieves the extinction ratio (ER) of 19.78 dB and insertion loss (IL) of 1.64 dB for the TE mode, ER of 7.78 dB and IL of 2.64 dB for the TM mode at the operating wavelength of 3.5 μ m. The PBS based on an asymmetric DC paves the way to achieve integrated waveplates, which has potential applications in the detection and analysis of airborne molecules and the optical communication techniques with large signal transmission capacity. • The PBS based on HPW has better transmission characteristics. • The PBS achieves the extinction ratio (ER) of 19.78 dB and 7.78 dB, and the insertion loss (IL) of 1.64 dB and 2.64 dB at the operating wavelength of 3. 5 μ m. • The working bandwidth of the PBS is 400 nm, providing a promising platform for increasing communication capacity. [ABSTRACT FROM AUTHOR]

In this paper, we propose a nonlinear interferometer based on two-port feedback nondegenerate optical parametric amplification (NITFPA), which employs two linear beam splitters to feed the two output beams of a nondegenerate optical parametric amplifier back to its input ports. By comparing the NITFPA with the SU(1,1) interferometer (SUI), which is another typical nonlinear interferometer, we demonstrate that the NITFPA has its unique advantages in the precision enhancement of the phase estimation. In addition, we demonstrate that the NITFPA is also advantageous over the SUI in the robustness against the losses. Such a NITFPA may find its potential applications in quantum metrology. • We propose a nonlinear interferometer based on two-port feedback nondegenerate optical parametric amplification (NITFPA), which cyclically utilizes the internal entanglement sources to boost the phase sensitive photon number inside the interferometer, with the help of the feedback structure. • Given the same sources of system, our NITFPA is able to boost the internal photon number of the interferometer, and thus makes the phase sensitivity of the NITFPA enhanced compared with the traditional SU(1,1) interferometer. • Considering the effect of losses, we found that NITFPA performs better in the robustness against the losses than SU(1,1). [ABSTRACT FROM AUTHOR]

In this paper, a polarization beam splitter using a pixelated directional coupler is proposed, designed, and experimentally demonstrated on silicon-on-insulator platform. According to the phase matching, structural parameters for the coupling region consisting of a straight waveguide and a pixelated waveguide are carefully selected by using direct-binary-search optimization algorithm and the finite difference time domain method, and thus the input fundamental transverse-magnetic and transverse-electric modes can be effectively separated from each other in an ultra-compact coupling length. The coupling length of our designed device is only 6 μ m. Experimental results reveal that, the measured polarization extinction ratio is greater than 14.22 dB and the corresponding insertion loss is smaller than 1.36 dB within a bandwidth from 1527 to 1580 nm for the fabricated device operating in transverse-electric polarization, while the measured polarization extinction ratio and insertion loss are respectively larger than 14.47 dB and lower than 1.53 dB from 1527 to 1580 nm for the fabricated device operating in transverse-magnetic polarization. • A PBS using a pixelated directional coupler is designed and experimentally demonstrated. • The coupling length of our designed device is only 6 μ m. • The measured PER and IL are respectively larger than 14.22 dB and less than 1.53 dB from 1527 to 1580 nm. [ABSTRACT FROM AUTHOR]

The intriguing discoveries of quantum spin Hall effect of electrons and its analogy in photon systems have renovated several concepts in condensed matter physics. Here we emulate topological edge states at microwave frequencies utilizing honeycomb photonic crystals with elliptical rods made of silicon material, and a novel topological beam splitter is implemented and analyzed. Robustness against perturbations provides the beam splitter with extremely strong transmission stability. Noticeably, suppressing the backward transmission of electromagnetic wave mitigates undesirable reflection interference. The numerical analysis results reveal that the splitting ratio obtained is in the range of 0.5–1.5 and the maximum transmittance value can reach up to 97% in this system. Besides, by appropriately adjusting the configuration parameters of photonic crystals, the location of operating frequency can be tuned to match different cases. The proposed structure has tremendous potential applications in the field of all-optical integrated circuits and will promote the practicability of photonic topological insulators in the communication domain • Based on the topological edge states theory, we have implemented a topological beam splitter utilizing honeycomb photonic crystals with elliptical rods made of silicon material in this paper. • The unique feature of present beam splitter is its robust unidirectional transmission. • The proposed configuration possesses stronger light confinement and spin guiding effect. • The topological beam splitter can suppress backscattering and is immunity to imperfections. • The system is concise and compact in structure and has broad operating bandwidth. [ABSTRACT FROM AUTHOR]

This paper presents a compact dual-mode polarization beam splitter (PBS) based on silicon on insulator platform. The proposed PBS separates two lowest-order transverse magnetic (TM) modes from two lowest-order transverse electric (TE) ones by employing an optimized tapered directional coupler. To the best of our knowledge, this is the first PBS with the ability of separating two sets of modes with different polarizations, simultaneously. Such a component is an essential block in the hybrid mode/polarization-multiplexing systems. The three-dimensional finite-difference time-domain (FDTD) simulation results confirm that the designed PBS has a low loss of 1.6 dB and high extinction ratio of more than 10 dB over a broad wavelength range of 90 nm. Also, the presented PBS tolerates ± 15 nm change in the coupling gap, ± 30 nm waveguide width deflection, and more than ± 100 nm coupling length variation with an insertion loss lower than 1 dB and extinction ratio higher than 10 dB. • Proposing the first dual-mode polarization beam splitter. • Separating two lowest-order TM modes from two lowest-order TE ones, at the same time. • Achieving the wide bandwidth of 90 nm and high extinction ratio of 10 dB. • Reducing the length, 7 times compared to the symmetric directional coupler structure. [ABSTRACT FROM AUTHOR]

An optical engine (OE) for stellar simulation systems with low extinction ratios (ERs) is proposed. This engine combines two orthogonal polarizers with a non-polarizing beam splitter to suppress the leakage of dark silicon-based liquid crystals (LCOS) in traditional systems. In this paper, a method to calculate the ER based on vector ray tracing is used. The new optical engine (OE) is demonstrated to have lower ERs than traditional systems. The calculations show that the maximum ER is 5 × 10−5 in the range of ± 8 ° , which is much lower than the ERs of traditional optical engines of 2.5 × 10−2. It reduces the ER by three orders of magnitude. The experimental results show that the new OE improves the ERs by 92.68% compared with the traditional system. [ABSTRACT FROM AUTHOR]

Under the second Bragg incidence, a new polarization-controlled grating is proposed based on the multilayer dielectric grating structure. This novel polarizing beam splitter can diffract TE wave in the 0th order and TM wave in the -1st/-2nd orders. In most reported polarization-selective dual-function beam splitter, two polarizations cannot be separated in the -1st order. While in this paper, as a polarizer, TE polarization and TM polarization propagate in different orders. At an incident wavelength of 800 nm, the efficiency of TE-polarized light is 99.32%. Both orders of TM-polarized light are more than 40%, and the extinction ratio is greater than 20 dB. This new high-efficiency polarizer can be used well in biosensors and optical communications. • Polarization-controlled under second Bragg incidence with silver deposited in groove. • TE wave reflection in the 0th order and TM wave splitter in the -1st/-2nd orders. • Reflection of 99.32% for TE wave and extinction ratio of 20 dB for TM wave. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the competence of the Fast Fourier Transform based beam propagation method (FFT-BPM) in the analysis of the diffraction of a Gaussian light beam by linearly binary chirped gratings. The visibility and the focusing of the diffraction orders are investigated thoroughly. The waist size and focal distance of the diffraction orders are extracted easily. Moreover, the key parameters that control the Gaussian beam deflection and focusing are examined for more improvement of the chirped grating lens operation and to design a beam splitter. The applicability and accuracy of the method is verified by comparing our results with those obtained by other analytical method. The comparison showed a good agreement. Furthermore, the illumination by flat-top beam profiles such as rectangular and super-gaussian are studied. [ABSTRACT FROM AUTHOR]

In this paper we studied the surface morphology of the grating fabricated on the soda-lime silicate glass using a 500 kHz, 1040 nm femtosecond laser. A nanocluster-ripple grating can be fabricated with proper processing parameters. Our results demonstrate that the scan line spacing plays an important role in the diffraction efficiency of the fabricated grating. Such gratings, used as a multi-beam splitter or a dispersion element, can be fabricated easily by changing the laser scan line spacing. [ABSTRACT FROM AUTHOR]