Optical Path Control Research Articles

Non-mechanical beam steering for high-speed optical wireless communications via electrowetting on dielectric.

Electrowetting on dielectric (EWOD) is used for non-mechanical optical beam steering (OBS) in optical communication systems. High-capacitance ion gel is used to construct an efficient electrowetting interface that facilitates dynamic OBS. This integration facilitates precise control of beam steering and data transmission efficiency in optical wireless communication systems. An EWOD-based liquid prism (LP) manipulates beam direction via electrowetting. The theoretical framework is supported by the Young and Young-Lippmann equations for precise optical path control. We present a theoretical and experimental demonstration of a two-dimensional beam steering system using an EWOD-based LP, with beam steering up to 14.82° and 14.39° along the X and Y axes, respectively. The system achieves data rates of 1.9 Gbps in free-space optics (FSO) and 1.7 Gbps in underwater wireless optical communication (UWOC) systems, with a measured bit error rate that adheres to the standard threshold of the forward error correction limit. Our results suggest that the EWOD-based LP system offers a compact, efficient, and versatile design for optical devices in both FSO and UWOC systems.

Improvement of instrumentation consistency using DUV filter in Spectroscopic Ellipsometry

In the process of mass-production of semiconductors, it has been continuously required to determine whether the process is normal or not, and for this, it must be premised that the measurement equipment can produce reliable and consistent measurement data. However, Due to the denaturation of Working Reference Material (WRM), which is the basis for judging the accuracy and precision of the equipment, it is difficult to maintain the consistency of the instrument. In this study, the effect of preventing WRM denaturation was analyzed through optical path control in Spectroscopic Ellipsometry (SE) equipment. Therefore, by applying it to actual equipment, It is suggested methods to improve measurement equipment reliability.

First intensity interferometry measurements with the H.E.S.S. telescopes

ABSTRACT Intensity interferometry for astrophysical observations has gained increasing interest in the last decade. The method of correlating photon fluxes at different telescopes for high resolution astronomy without access to the phase of the incoming light is insensitive to atmospheric turbulence and does not require high-precision optical path control. The necessary large collection areas can be provided by Imaging Atmospheric Cherenkov Telescopes. Implementation of intensity interferometers to existing telescope systems such as VERITAS and MAGIC has proven to be successful for high-resolution imaging of stars. In 2022 April we equipped two telescopes of the H.E.S.S. array in Namibia with an intensity interferometry setup to measure southern sky stars and star systems during the bright moon period. We mounted an external optical system to the lid of the telescope cameras, which splits the incoming light and feeds it into two photomultipliers in order to measure the zero-baseline correlation within one telescope in addition to the cross-correlation between the telescopes. The optical elements are motorized, which enables live correction of tracking inaccuracies of the telescopes. During the campaign we measured the spatial correlation curves and thereby the angular diameters of λ Sco (Shaula) and σ Sgr (Nunki), while we also performed systematic studies of our interferometer using the multiple star system of α Cru (Acrux).

Flexible photonic composites with responsive information display based on optical path control

Artificial photonic composites can exhibit the structural colors of embedded colloidal arrays and the functionality of polymeric matrix, making them suitable for emerging applications, such as display, sensing, and information security. However, their ability to integrate flexibility, color visibility and stimulus-responsive macroscopic change has not been adequately harnessed. In this study, a self-supporting photonic composite film is constructed by incorporating isotropically arranged polysulfide nanoparticles (PSNs) into polyethylene glycol diacrylate and butyl acrylate copolymers. The inherent light-absorbing properties and high refractive index of PSNs impart the photonic composites with high structural color visibility. Furthermore, the flexible copolymer network enables sustainable optical capability of photonic pattern during deformation. Due to its unique hydrophobic and hydrophilic structures, tunable optical path control can be achieved through solvent-induced microphase separation and inverse transparency changes under thermal stimulation, resulting in self-encryption and decryption. The function of switching desired stimuli into visualized optical signals allows flexible photonic composites to present great prospects in smart materials for dynamic memory devices.

Research on Optical Path and Phase Simultaneous Control in Coherent Beam Combining of Broadband Laser Based on Spectral Filtering

Research on Optical Path and Phase Simultaneous Control in Coherent Beam Combining of Broadband Laser Based on Spectral Filtering

Особенности работы системы регулировки периметра резонатора и вибрационная ошибка зеемановского лазерного гироскопа на 50%-ной смеси изотопов неона

Особенности работы системы регулировки периметра резонатора и вибрационная ошибка зеемановского лазерного гироскопа на 50%-ной смеси изотопов неона

One-soliton shaping and two-soliton interaction in the fifth-order variable-coefficient nonlinear Schrödinger equation

One- and two-soliton analytical solutions of a fifth-order nonlinear Schrodinger equation with variable coefficients are derived by means of the Hirota bilinear method in this paper. Various scenarios of one-soliton shaping and two-soliton interaction and reshaping are investigated, using the obtained exact solutions and adjusting parameters of the underlying model. We find that widths of two colliding solitons can change without changing their amplitudes. Furthermore, we produce a solution in which two originally bound solitons are separated and are then moving in opposite directions. We also show that two colliding solitons can fuse to form a spatiotemporal train, composed of equally separated identical pulses. Moreover, we display that the width and propagation direction of the spatiotemporal train can change simultaneously. Effects of corresponding parameters on the one-soliton shaping and two-soliton interaction are discussed. Results of this paper may be beneficial to the application of optical self-routing, switching and path control.

Ultrahigh precision synchronization of optical and microwave frequency sources

In this paper we demonstrate that balanced optical-microwave phase detectors (BOMPD) are able to provide a robust long-term optical-RF synchronization with subfemtosecond residual timing drift over 24 hours in laboratory conditions without active temperature control of optical and electronic paths. Moreover, 10.833 GHz Sapphire-loaded cavity oscillator (SLCO) was successfully disciplined by 216.66 MHz laser oscillator using the BOMPD which resulted in a sub-femtosecond RMS jitter integrated from 1 Hz to 1 MHz.

Analysis of multiwavelength coherent beam combining effect

The combination effect of multiwavelength active coherent beam combination (CBC) is investigated theoretically. The dependence of the combination effect on the optical path control precision, spectral width, wavelength number, and channel number is revealed. In the case of small optical path variance, the combination effect approximately decreases in quadratic form with wavelength number N, spectral width Δν, and optical path variance σ increasing. In the case of large optical path variance, the combination effect is independent of the optical path variance and the spectral width. The larger the wavelength number is, the smaller the Strehl ratio expectation is, and it finally degenerates to the incoherent combination. The necessity of optical path control is discussed. This study is helpful for multiwavelength CBC system design and the combination effect estimation.

광섬유 피드 리트로마운트형 분광계

A low-dispersion fiber feed Littrow-mounted grating spectrometer for education was designed and fabricated. The dispersion element is a reflective type blazed grating Edmundoptics NT 46-075 (spatial frequency 600 lines/mm, dimension <TEX>$30mm{\times}30mm$</TEX>, blazed angle 8.6 degree). The optical fiber coupler module for optical guiding from telescope to spectrometer is composed of a multi-mode FC connector - FC connector optical fiber patch cord (core/cladding diameter <TEX>$50{\mu}m/125{\mu}m$</TEX>) and two 1.25" throw-tube couplers. The lens for collimating and imaging is a general purpose focal length 50 mm camera lens (f/1.8). The device for optical path control is a rectangular prism (size <TEX>$25mm{\times}25mm$</TEX>). The imaging camera sensor is a Meade DSI Pro 2 CCD sensor (black and white, <TEX>$752{\times}582$</TEX> pixels and pixel size <TEX>$8.3{\mu}m{\times}8.6{\mu}m$</TEX>). Softwares for data logging and analysis consist of Meade Autostar Suite, NIH imagej and Vernier Logger Pro 3. The wavelength coverage range of the spectrometer is 205 nm at central wavelength 550 nm. The wavelength resolution is 1.7 nm.

Numerical analysis with active phase matching of multi-line deuterium-fluoride laser beam array

Coherent beam combination can promote the emitting power of chemical laser in the extremely high power application. To achieve chemical laser coherent combining the optical paths of each channel should be adjusted to the same for the multi-line spectral characteristic and the combination effect is highly dependent on the optical path variance. The dependence of the combination effect on the optical path variance is calculated taking deuterium-fluoride (DF) laser for example. The feasibility and the validity of the multi-line chemical laser coherent combining are discussed with different optical path variances. The coherent combination of multi-line chemical laser is not totally unattainable as long as the precise optical path control measure is involved. To achieve excellent combination effect for chemical laser with ordinary optical path control measure, line-selecting technology is commonly needed.

Piezoelectric actuators for the correction of optical ray path in the operation of laser gyros

In the operations of laser gyros, geometric variations due to temperature, manufacturing misalignments and operation environments cause thermo-elastic deformations of their components, which lead to changes of the area and perimeter of their resonator block. The ray transfer matrix in the geometric optics can be utilized to predict the optical ray paths on the basis of the temperature environments as well as the misalignment of mirrors. The distance and orientation (or slope) at the arbitrary plane inside the resonator along the ideal optical path can be calculated from the chain multiplication of the ray transfer matrix for each optical component in one round trip. The geometric scale factor variations can be corrected by the piezoelectric actuator based on the design parameters of optical path control in the resonator. For the effective corrections of it, the feasible designs of piezoelectric actuator are required. This paper presents the numerical formulation of the elastic behavior of each piezoelectric actuator and the numerical formulations are verified through the comparisons with the results of finite element simulation and experiments.

Optical path control of solitary waves in dye-doped nematic liquid crystals

The light-induced steering of spatial optical solitary waves in dye-doped nematic liquid crystals is analyzed. Shining a control beam through the cell results in a boundary mediated change in the orientation of the molecular director, thereby a perturbation in the refractive index of the medium. This re-orientational effect can optically steer spatial solitary waves propagating in an orthogonal plane within the liquid crystal layer. The equations governing this steering are solved using a Lagrangian formulation, resulting in modulation equations for the self-trapped beam path. Very good agreement is obtained between solutions of the modulation equations and numerical solutions of the full governing equations. Full Text: PDF

54.4: Highly Efficient and Wide Color Gamut White OLED Architecture for Display Application

AbstractHighly efficient WOLEDs, with the efficiencies of 19 cd/A, 16 cd/A, and 33 cd/A and CIE color coordinates of (0.25, 0.35), (0.30, 0.32), and (0.30, 0.32) respectively, have been developed. The broad white emitting TE‐WOLEDs for high resolution display have been realized by controlling the microcavity between the cathode and anode. 96 % of NTSCx,y ratio was achieved from the TE‐WOLED with the optical path control layer (OPCL) and new green color filter (CF).

36.4: A Novel Seamless Tiling Technology for High Resolution OLED Displays

AbstractA novel seamless tiling technology for high resolution OLED displays is described. This technology is mainly based on geometric arrangement of each pixels and optical path control of OLED displays. Computer simulations have been used to find and confirm the best conditions for seamless OLED displays. A 2 × 1 tiled, 72ppi resolution, 8″ diagonal size AM‐OLED seamless tiled display prototype was fabricated.

Holographic generation of complex fields with spatial light modulators: application to quantum key distribution

There has been considerable interest recently in the generation of azimuthal phase functions associated with photon orbital angular momentum (OAM) for high-dimensional quantum key distribution. The generation of secure quantum keys requires not only this pure phase basis but also additional bases comprised of orthonormal superposition states formed from the pure states. These bases are also known as mutually unbiased bases (MUBs) and include quantum states whose wave functions are modulated in both phase and amplitude. Although modulo 2pi optical path control with high-resolution spatial light modulators (SLMs) is well suited to creating the azimuthal phases associated with the pure states, it does not introduce the amplitude modulation associated with the MUB superposition states. Using computer-generated holography (CGH) with the Leith-Upatnieks approach to hologram recording, however, both phase and amplitude modulation can be achieved. We present a description of the OAM states of a three-dimensional MUB system and analyze the construction of these states via CGH with a phase-modulating SLM. The effects of phase holography artifacts on quantum-state generation are quantified and a prescription for avoiding these artifacts by preconditioning the hologram function is presented. Practical effects associated with spatially isolating the first-order diffracted field are also quantified, and a demonstration utilizing a liquid-crystal SLM is presented.

Development of terabit‐class super‐networking technologies

AbstractWe propose terabit‐class super‐networking technologies, designed to improve the scalability, reliability and performance of optical Internet protocol networks. Our technologies comprise both intra‐ and interlayer traffic engineering technologies. The intralayer technologies include an optical path protection scheme, an electrical load‐balancing scheme and a distributed content‐caching scheme. These provide an effective and economical way of improving performance and reliability. The interlayer technologies include both traffic‐driven and application‐driven optical cut‐through control schemes and a policy control scheme. These provide an effective and economical way of improving scalability and performance. The feasibility of our technologies has been verified by means of experiments using prototype systems. The results showed that the different techniques can be combined to form a single network architecture for dynamic optical path control. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley &amp; Sons, Inc.

Wavelength-dependent characteristics of modulo Nλ0 optical wavefront control

A Fourier analysis treatment of the wavelength dependences associated with modulo lambdar optical path control, treating the general case of a modulo lambdar optical path difference function OPD (x, y) mod lambdar in which the reset wavelength lambdar, is allowed to be an integer multiple of a nominal wavelength lambda0, lambdar=Nlambda0, is presented. Equations are derived describing the wavelength-dependent characteristics of the diffraction efficiency and the wavefront errors associated with all diffracted orders. The results are applied to the cases of diffraction of a planar wavefront and compensation of large aberrations and show that over an extended spectral bandwidth the output field consists of multiple diffracted orders with a range of fractional wavefront errors that diminishes with increasing reset multiple N, but does not reach the diffraction limit associated with conventional optics.

Field trial of all-optical 40 Gbps transmission system for next-generation networks

The National Institute of Informatics (NII) has been conducting joint research with JapanTelecom to develop a 40 Gbps optical transport system for the next-generation SuperSINET. We report on the recent results of field trials focused on automatic chromatic dispersion compensation and path protection/restoration applied to the future SuperSINET as key technologies required to maintain the quality of transmission, to reduce operational costs, and to facilitate the enhancement of network capabilities. From the results of the field trial, we have confirmed that an automatic optical path control system is essential in an all-optical wavelength path network.

Depth-enhanced integral imaging by use of optical path control.

The image depth of integral imaging is enhanced by doubling the number of central depth planes by use of optical path control. To accomplish this, the optical path lengths are changed by controlling whether reflections occur behind the lens array. We propose three schemes that use mirrors, a combination of beam splitters and polarizers, and polarization beam splitters, respectively. In experiments we implement the systems that are completely electronically controllable, are compact, and provide two central depth planes with 50.4-mm separation.