Light Modulator Research Articles

Stimulated Raman-induced beam focusing.

Stimulated Raman scattering, employing a pump and a Stokes beam, exhibits itself through both the Raman loss observed in the pump beam and the Raman gain in the Stokes beam. This phenomenon finds application in spectroscopy for chemical analyses and microscopy for label-free bioimaging studies. Recent efforts have been made to implement super-resolution Raman microscopy using a doughnut-shaped pump, Stokes, or depletion beam. In this study, it is shown that the amplitude and phase of the pump or Stokes beam undergo significant modulation through the stimulated Raman process when they are configured as one of the higher-order Laguerre-Gauss modes, achieved using appropriate spiral phase plates or spatial light modulators. The resulting intensity distributions of the pump and Stokes beams are determined by a superposition of multiple Laguerre-Gauss modes that are coupled through nonlinear Raman gain and loss processes. Calculation results are used to elucidate the limitations associated with super-resolution coherent Raman imaging with a toroidal pump or Stokes beam. This stands in contrast with the stimulated emission depletion fluorescence microscopy technique, which has no fundamental limit in the spatial resolution enhancement.

Decoupling Plasmonic Hot Carrier from Thermal Catalysis via Electrode Engineering.

Increased attention has been directed toward generating nonequilibrium hot carriers resulting from the decay of collective electronic oscillations on metal known as surface plasmons. Despite numerous experimental endeavors, demonstrating hot carrier-mediated photocatalysis without a heating contribution has proven challenging, particularly for single electron transfer reactions where the thermal contribution is generally detrimental. An innovative engineering solution is proposed to enable single electron transfer reactions with plasmonics. It consists of a photoelectrode designed as an energy filter and photocatalysis performed with light function modulation instead of continuously. The photoelectrode, consisting of FTO/TiO2 amorphous (10 nm)/Au nanoparticles, with TiO2 acting as a step-shape energy filter to enhance hot electron extraction and charge-separated state lifetime. The extracted hot electrons were directed toward the counter electrode, while the hot holes performed a single electron transfer oxidation reaction. Light modulation prevented local heat accumulation, effectively decoupling hot carrier catalysis from the thermal contribution.

Preparation and properties of tellurite glass-based CsPb(BrCl)3@glass fluorescent film for a white light emitting diode color converter

Perovskite nanocrystal glass has the advantages of narrow-band emission, easy tuning, and stable structural, physical, and chemical properties, and can be used to mix with other colored materials for white light modulation. The current white light mode widely adopts the packaging method of blue light chip and yellow phosphor, which has the problem of a blue-yellow cavity and low light quality. In this work, the central wavelength of CsPb(BrCl)3 can be adjusted continuously ranging from 463 nm to 486 nm by adjusting the relative ratio of bromine to chlorine in nanocrystals. On the basis of the previous design of YAG:Ce phosphor-in-glass, perovskite nanocrystal glass powder as a color compensator was introduced into the tellurite glass matrix to form a doubly encapsulated system by low-temperature co-sintering. The yellow phosphor and perovskite nanocrystal glass maintain good structural integrity in the glass matrix. By combining the double-package fluorescent material with the blue chip, the continuous adjustment of chromaticity coordinates along the saddle line is realized, and the color-rendering index is also improved to 81.3.

Coherent beam combining of optical vortices.

We experimentally demonstrate the power scaling of optical vortices using the coherent beam combining technique, encompassing topological charges ranging from ℓ = 1 to ℓ = 5 realized on the basis of a Yb-doped fiber short-pulsed laser system. The combining efficiency varies from 83.2 to 96.9% depending on the topological charge and beam pattern quality generated by the spatial light modulators. This work is a proof of concept for using a coherent beam combining technique to surpass the physical power/energy limitation of any single source of optical vortices, regardless of the generation methods employed. These results open a pathway to power scaling of optical vortices with diverse applications in science and industry by utilizing advances in light-matter interactions.

High-fidelity and high-speed wavefront shaping by leveraging complex media.

High-precision light manipulation is crucial for delivering information through complex media. However, existing spatial light modulation devices face a fundamental speed-fidelity tradeoff. Digital micromirror devices have emerged as a promising candidate for high-speed wavefront shaping but at the cost of compromised fidelity due to the limited control degrees of freedom. Here, we leverage the sparse-to-random transformation through complex media to overcome the dimensionality limitation of spatial light modulation devices. We demonstrate that pattern compression by sparsity-constrained wavefront optimization allows sparse and robust wavefront representations in complex media, improving the projection fidelity without sacrificing frame rate, hardware complexity, or optimization time. Our method is generalizable to different pattern types and complex media, supporting consistent performance with up to 89% and 126% improvements in projection accuracy and speckle suppression, respectively. The proposed optimization framework could enable high-fidelity high-speed wavefront shaping through different scattering media and platforms without changes to the existing holographic setups, facilitating a wide range of physics and real-world applications.

Entanglement and correlations in an exactly-solvable model of a Bose–Einstein condensate in a cavity

An exactly solvable model of a trapped interacting Bose–Einstein condensate (BEC) coupled in the dipole approximation to a quantized light mode in a cavity is presented. The model can be seen as a generalization of the harmonic-interaction model for a trapped BEC coupled to a bosonic bath. After obtaining the ground-state energy and wavefunction in closed form, we focus on computing the correlations in the system. The reduced one-particle density matrices of the bosons and the cavity are constructed and diagonalized analytically, and the von Neumann entanglement entropy of the BEC and the cavity is also expressed explicitly as a function of the number and mass of the bosons, frequencies of the trap and cavity, and the cavity-boson coupling strength. The results allow one to study the impact of the cavity on the bosons and vice versa on an equal footing. As an application we investigate a specific case of basic interest for itself, namely, non-interacting bosons in a cavity. We find that both the bosons and the cavity develop correlations in a complementary manner while increasing the coupling between them. Whereas the cavity wavepacket broadens in Fock space, the BEC density saturates in real space. On the other hand, while the cavity depletion saturates, and hence does the BEC-cavity entanglement entropy, the BEC becomes strongly correlated and eventually increasingly fragmented. The latter phenomenon implies single-trap fragmentation of otherwise ideal bosons, where their induced long-range interaction is mediated by the cavity. Finally, as a complimentary investigation, the mean-field equations for the BEC-cavity system are solved analytically as well, and the breakdown of mean-field theory for the cavity and the bosons with increasing coupling is discussed. Further applications are envisaged.

Bentuk Penyajian Tari Manggang Kemplang Oleh Sanggar Kipas Emas Di Kelurahan Timbangan Ogan Ilir

Manggang Kemplang Dance is a dance that tells about the manggang kemplang tradition which reflects the local wisdom of the Ogan Ilir people in utilizing natural resources and local wisdom in processing food which is danced by 5 dancers. The problem in the research is the form of presentation of the Manggang Kemplang dance in Timbangan Village, Ogan Ilir Regency. The aim of this research is to find out and describe the form of presentation of the Manggang Kemplang dance by the Golden Fan Studio in Timbangan Village, Ogan Ilir Regency. This research uses qualitative methods with data collection techniques in the form of observation, interviews, documentation and literature study. The form of presentation of the Manggang Kemplang dance consists of aspects of choreographic elements which include dance movements, dance space, accompaniment/accompaniment music, dance title, dance theme, dance type, mode of presentation, dancers, fashion, make-up, lighting and props. .

O-113 Non-invasive evaluation of embryo metabolic activity through hyperspectral microscopy

Abstract Current approaches for assessing embryo quality are subjective (morphology) or invasive (biopsy) and are not always predictive of live birth. Development of an accurate and non-invasive method to assess embryo quality would likely improve IVF success. We have taken a different approach towards developing a non-invasive diagnostic for embryo quality: optical imaging. We use low levels of light to illuminate the embryo and obtain spatial information on cell metabolism as well as biophysical properties of the embryo. Here I will present our work showing that hyperspectral imaging can be used to accurately discriminate between euploid and aneuploid mouse embryos, and in light sheet mode, able to generate 3D metabolic maps of developing embryos. Importantly, we show that this form of imaging is safe: compared to embryos that were not imaged, hyperspectral imaged embryos had similar, and not significantly different, pregnancy and implantation rates, with offspring weight at weaning also comparable. Another potential optical approach to assess embryo quality is digital holographic imaging. To date, little attention has been paid to the physical parameters of an embryo and whether these could be markers of embryo quality. One such physical parameter is refractive index. We have shown that digital holographic microscopy is able to measure very small changes in refractive index between good and poor-quality mouse embryos. Importantly, these optical approaches occur in the absence of stains or exogenous tags. Used alone, or in combination, such optical approaches may prove beneficial in developing an accurate, non-invasive diagnostic for embryo quality.

Very-large-scale-integrated high quality factor nanoantenna pixels.

Metasurfaces precisely control the amplitude, polarization and phase of light, with applications spanning imaging, sensing, modulation and computing. Three crucial performance metrics of metasurfaces and their constituent resonators are the quality factor (Q factor), mode volume (Vm) and ability to control far-field radiation. Often, resonators face a trade-off between these parameters: a reduction in Vm leads to an equivalent reduction in Q, albeit with more control over radiation. Here we demonstrate that this perceived compromise is not inevitable: high quality factor, subwavelength Vm and controlled dipole-like radiation can be achieved simultaneously. We design high quality factor, very-large-scale-integrated silicon nanoantenna pixels (VINPix) that combine guided mode resonance waveguides with photonic crystal cavities. With optimized nanoantennas, we achieve Q factors exceeding 1,500 with Vm less than 0.1 . Each nanoantenna is individually addressable by free-space light and exhibits dipole-like scattering to the far-field. Resonator densities exceeding a million nanoantennas per cm2 can be achieved. As a proof-of-concept application, we show spectrometer-free, spatially localized, refractive-index sensing, and fabrication of an 8 mm × 8 mm VINPix array. Our platform provides a foundation for compact, densely multiplexed devices such as spatial light modulators, computational spectrometers and in situ environmental sensors.

Single-pixel microscopy with optical sectioning.

Imaging with single-pixel detectors offers a valuable alternative to the conventional focal plane array strategy, especially for wavelengths where silicon-based sensor arrays exhibit lower efficiency. However, the absence of optical sectioning remains a challenge in single-pixel microscopy. In this paper, we introduce a single-pixel microscope with optical sectioning capabilities by integrating single-pixel imaging (SPI) techniques with structured illumination microscopy (SIM) methods. A spatial light modulator positioned at the microscope's input port encodes a series of structured light patterns, which the microscope focuses onto a specific plane of the 3D sample. Simultaneously, a highly sensitive bucket detector captures the light reflected by the object. Optical sectioning is achieved through a high-frequency grating positioned at the microscope's output port, which is conjugated with the spatial light modulator. Utilizing SPI reconstruction techniques and SIM algorithms, our computational microscope produces high-quality 2D images without blurred out-of-focus regions. We validate the performance of the single-pixel microscope (SPM) by measuring the axial response function and acquiring images of various 3D samples in reflected bright-field configuration. Furthermore, we demonstrate the suitability of the optical setup for single-pixel fluorescence microscopy with optical sectioning.

O-229 Neck scarf of ureter and Intraoperative ICG-fluorescence for preventing ureters injuries in Da Vinci Robotic deep infiltrating endometriosis excision

Abstract Study question To prevent ureters injury during deep infiltrating endometriosis excision. Summary answer Identify the ureter course with ICG and near-infrared fluorescence (NIRF) imaging mode and traction with a vessel loop like neck scarf in white light mode. What is known already Deep infiltrating endometriosis is one of the most challenging gynecologic operation due to the distorted anatomy by the fibrosis of endometriosis gland.Identification of ureters through intraurethral ICG instillation and NIRF imaging has been reported to be useful during robotic surgery. However, surgeons cannot do robotic ureterolysis in Firefly NIRF imaging mode. When shift back to the white light mode, surgeons could only try to remember the ureter course during the ureterolysis procedure.When the ureter course was in doubt, the surgeon must shift back to the ICG-NIRF image mode again. Study design, size, duration From 2017 Jan1 till 2024 Jan 7, a single surgeon perform 47 consecutive patients with DIE received robotic surgery with ureterolysis from pelvic brim to the level of uterine vessels crossing them. Yellow and blue rubber bands were used to collar the ureters as a neck scarf, with Da Vinci robot system (SI, XI)The third arm as an stable assistant to traction the neck scarf to traction ureter indirectly in different direction when ureterolysis. Participants/materials, setting, methods We perform cystoscopy and intraurethral ICG injection with or without ureteral stent placement and Inject ICG-fluorescence with Firefly fluorescence imaging if the ureters were hard to find due to adhesion and fibrosis. Under the Firefly NIRF imaging mode,the location of ureter over the pelvic brim was found and the vessel loops were set up. Then shift back to white light mode to do the ureterolysis. Main results and the role of chance 47 consecutive patients with deep infiltrating endometriosis were safely operated without fistula, ureter injury, laceration during one month to 5 years period follow up. In them 2 patients need cystoscopy and ICG-NIRF help to setting up the vessel’s loops. Conclusion The surgeons could always keep the ureter safety during difficult endometriosis dissection with the vessel loops over the ureter as a neck scarf.There will be an indirect traction force pulled by robotic assistant forceps in the regular robotic laparoscopy light source mode during ureterolysis. The Firefly NIRF imaging mode could be used to help in setting up the neck scarf of ureters when the adhesion and fibroisis made the ureters course obscure. Limitations, reasons for caution Indocyanine Green is a fluorescent substance visible in near-infrared light. It is FDA-approved with IV injection for the identification of anatomical structures.The intra-ureteral ICG injection is off-label use. Wider implications of the findings Our techniques could be applied to all pelvic surgeries especially DIE, broad ligament and cervix myoma, scar defect repair and gynecologic cancer surgery, to preventing the ureters injured. However, further studies will be warranted. Trial registration number non-clinical trials

Transfer of optical vortices in a coherently-prepared rare-earth-ion-doped solid

Optical vortices carrying orbital angular momentum (OAM) of light have earned much attention due to their potential applications in the classical and quantum physics. Quantum coherence has been proved to be an important tool for controlling the behavior of light fields. Developing the manipulation method of optical vortices is very useful for high-dimensional information processing encoded with OAM. In this paper, we experimentally investigate the transfer of optical vortices between different light modes in a coherently-prepared solid-state medium. Utilizing the technique of fractional stimulated Raman passage (f-STIRAP), the experimental medium is prepared into a coherent superposition of two ground states. By applying a probe vortex beam to scatter the induced atomic coherence, a new signal is generated with the same vorticity as that of the input probe field. Furthermore, the vortex beams are used as the f-STIRAP preparation pulses, and the helical phases of the vortex beams are mapped into the coherent superposition state. Subsequently, the optical vortices of the preparation pulses are transferred to a new light mode by using the probe beam to interact with the coherent medium. The new signal field accumulates the total topological charges of the applied fields in this coherent process. Such an experimental demonstration will enrich the interactions between optical vortices and matter, and can be helpful in further information processing.

Full-Dimensional Geometric-Phase Spatial Light Metamodulation.

Full-dimensional spatial light modulation requires simultaneous, arbitrary, and independent manipulation of the spatial phase, amplitude, and polarization. This is crucial for leveraging the complete physical dimension resources of light. However, full-dimensional metamodulation can be challenging due to the need for multiple independent control factors. To address this challenge, here we propose parallel-tasking metasurfaces to enable full-dimensional spatial light metamodulation based fully on the geometric-phase concept. Indeed, the meta-atoms are divided into several subphases, each of which serves as an independent control factor to manipulate light phase, amplitude, and polarization through geometric phase, interference, and orthogonal polarization superposition, respectively. Therefore, the macroscopic group of meta-atoms leads to metasurfaces that can achieve broadband full-dimensional spatial light metamodulation, as demonstrated by various types of structured light generation. This approach paves the way to future wide applications of light manipulation enabled by full-dimensional spatial light metamodulation.

Generation of wavelength- and orbital angular momentum-tunable extreme-ultraviolet vortex beams using a spiral phase mirror

To generate or manipulate the orbital angular momentum (OAM) of light, various optical elements, such as spiral phase plates, spatial light modulators, diffractive optical elements, and spiral phase mirrors (SPMs) have been used. In contrast to other optical components, the SPM depends only on the angle of incidence, which allows for the manipulation of the OAM values by simply rotating a single SPM or changing the angle of incidence of light. This study theoretically demonstrated the generation of high-quality vortex beams in the X-ray region (within a range of several tens of nanometers) beyond the existing visible and infrared regions using a SPM. Based on the geometry of grazing incidence, by rotating a single SPM, we obtained wavelength-tunable vortex beams with an identical OAM value of l = 1 in the 20–40 nm wavelength range and OAM-tunable vortex beams with various OAM values ranging from l = 3 to l = 5 at a 10 nm wavelength. Based on these characteristics, the tuning range of an SPM was discussed and the variation in the major radius of the elliptical beam formed on the SPM by grazing incidence was analyzed to realize SPM manufacturing. This novel optical technique holds great promise for enabling light-matter interactions at the nanometer scale, such as in the molecular or atomic regions, by implementing easily controllable wavelength- and OAM-tunable vortex beams based on a single SPM.

Time-of-flight resolved stimulated Raman scattering microscopy using counter-propagating ultraslow Bessel light bullets generation

We present a novel time-of-flight resolved Bessel light bullet-enabled stimulated Raman scattering (B2-SRS) microscopy for deeper tissue 3D chemical imaging with high resolution without a need for mechanical z-scanning. To accomplish the tasks, we conceive a unique method to enable optical sectioning by generating the counter-propagating pump and Stokes Bessel light bullets in the sample, in which the group velocities of the Bessel light bullets are made ultraslow (e.g., vg ≈ 0.1c) and tunable by introducing programmable angular dispersions with a spatial light modulator. We theoretically analyze the working principle of the collinear multicolor Bessel light bullet generations and velocity controls with the relative time-of-flight resolved detection for SRS 3D deep tissue imaging. We have also built the B2-SRS imaging system and present the first demonstration of B2-SRS microscopy with Bessel light bullets for 3D chemical imaging in a variety of samples (e.g., polymer bead phantoms, biological samples such as spring onion tissue and porcine brain) with high resolution. The B2-SRS technique provides a > 2-fold improvement in imaging depth in porcine brain tissue compared to conventional SRS microscopy. The method of optical sectioning in tissue using counter-propagating ultraslow Bessel light bullets developed in B2-SRS is generic and easy to perform and can be readily extended to other nonlinear optical imaging modalities to advance 3D microscopic imaging in biological and biomedical systems and beyond.

Highly versatile, two-color setup for high-order harmonic generation using spatial light modulators.

We present a novel, interferometric, two-color, high-order harmonic generation setup based on a turn-key Ytterbium-doped femtosecond laser source and its second harmonic. Each interferometer arm contains a spatial light modulator with individual capabilities to manipulate the spatial beam profiles and to stabilize the relative delay between the fundamental and the second harmonic. In addition, separate control of the relative power and focusing geometries of the two color beams is implemented to conveniently perform automated scans of multiple parameters. A live diagnostics system gives continuous information during ongoing measurements.

Phase-modulated multi-foci microscopy for rapid 3D imaging

3D imaging technology is pivotal in monitoring the functional dynamics and morphological alterations in living cells and tissues. However, conventional volumetric imaging associated with mechanical z-scanning encounters challenges in limited 3D imaging speed with inertial artifact. Here, we present a unique phase-modulated multi-foci microscopy (PM3) technique to achieve snapshot 3D imaging with the advantages of extended imaging depths and adjustable imaging intervals between each focus in a rapid fashion. To accomplish the tasks, we utilize a spatial light modulator (SLM) to encode the phases of the scattered or fluorescence light emanating from a volumetric sample and then project the multiple-depth images of the sample onto a single charge-coupled device camera for rapid 3D imaging. We demonstrate that the PM3 technique provides ∼55-fold improvement in imaging depth in polystyrene beads phantom compared to the depth of field of the objective lens used. PM3 also enables the real-time monitoring of Brownian motion of fluorescent beads in water at a 15 Hz volume rate. By precisely manipulating the phase of scattered light on the SLM, PM3 can pinpoint the specific depth information in living zebrafish and rapidly observe the 3D dynamic processes of blood flow in the zebrafish trunk. This work shows that the PM3 technique developed is robust and versatile for fast 3D dynamic imaging in biological and biomedical systems.

Visualization of cecal tumor by near-infrared laparoscopy and intraoperative colonoscopy

BackgroundIn laparoscopic colorectal surgery, accurate localization of a tumor is essential for ensuring an adequate ablative margin. Therefore, a new method, near-infrared laparoscopy combined with intraoperative colonoscopy, was developed for visualizing the contour of a cecal tumor from outside of the bowel. The method was used after it was verified on a model that employed a silicone tube.Case presentationThe patient was a 77-year-old man with a cecal tumor near the appendiceal orifice. Laparoscopy was used to clamp of the terminal ileum, and a colonoscope was then inserted through the anus to the cecum. The laparoscope in the normal light mode could not be used to identify the cecal tumor. However, a laparoscope in the near-infrared ray mode could clearly visualize the contour of the cecal tumor from outside of the bowel, and the tumor could be safely resected by a stapler. The histopathological diagnosis of the resected specimen was adenocarcinoma with an invasion depth of M and a clear negative margin.ConclusionsThis is the first report of the laparoscopic detection of the contour of a cecal tumor from outside the bowel. This technique is useful and safe for contouring tumors in laparoscopic colorectal surgery and can be used in various surgeries that combine endoscopy and laparoscopy.

OVERVIEW OF THE INFLUENCE OF INNOVATIVE TECHNOLOGIES ON EXPANDING THE FUNCTIONAL CAPABILITIES OF AUTOMOBILE HEADLIGHTS, ON THEIR PHOTOMETRIC CHARACTERISTICS AND METHODS AND MEANS OF THEIR CONTROL UNDER THE CONDITIONS OF OPERATION

A brief overview of the features and possibilities of innovative technologies in the field of front light-ing systems of mechanical vehicles, in particular, adaptive front lighting systems, intelligent front lighting sys-tems and modern digital lighting systems, was conducted. The main features of the structure and operation of such systems are considered, and some characteristics and capabilities of the front lighting systems used in Mercedes-Benz cars are given. Analyzed the requirements of the UNECE Rules and state standards of Ukraine in force in Ukraine with the requirements for methods and means of monitoring the conformity of installation parameters and photometric characteristics of front lighting systems during the operation of cars and the re-quirements of the manufacturer’s normative and technological documents for the performance of control, di-agnostic and regulatory maintenance work front lighting systems of Mercedes-Benz cars. The results of the work performed were used in the development of methodological instructions for the performance by NTU stu-dents of laboratory work on maintenance and inspection of the condition and adjustments of Mercedes-Benz headlights. Based on the results of the research, proposals and recommendations have been developed regard-ing the expediency of making changes to the state standards and regulatory documents in force in Ukraine, which regulate the performance of works to control the compliance of the technical condition of mechanical road vehicles with safety requirements in terms of external lighting devices. Also, recommendations have been developed for the use of control and diagnostic equipment, with which it is advisable to equip posts for mainte-nance of external light devices of Mercedes-Benz cars by maintenance stations located in Ukraine. Keywords: car headlight, adaptive front lighting system, intelligent front lighting system, digital lighting sys-tem, dynamic cornering lighting, static cornering lighting, low beam headlights, high beam headlights, adaptive low beam, adaptive high beam, city light mode, extra-urban mode light, light mode on highways; advanced fog light mode, fog light, matrix LED light, light with micro-opto-electromechanical system.

Review Paper on Street Light Automatic Intensity Controller

Abstract: This paper is planned for making more secure roadways with canny light framework to lessen power utilization. This framework has programmed road light power control dependent on the vehicular development and turning ON and OFF of road lights relying upon the light atmosphere. This will help in decreasing the power utilization during long periods of small street use. The road light module is introduced subsequently for each specific separation. This paper additionally targets lessening street mishaps by recognizing utilization of liquor by the driver. This can be actualized utilizing liquor sensor module which contains skin sensor, breath liquor sensor and nearness sensor. The skin sensor and broadness liquor sensor distinguish the nearness of liquor content and the nearness sensor helps in identifying any sort of misbehaviour. The oddity of this paper is to successfully lessen the vitality utilization of the road lights by controlling the road light's force, detecting both human just as vehicular development and injury and passing brought about by alcoholic driving can be forestalled by earlier detecting of the liquor content in drivers by a basic and affordable way..