Abstract Osteonecrosis becomes a more widespread problem as the population is getting older. Current osteonecrosis diagnosis not only requires invasive procedures but also often leads to surgical replacement. This paper reports a preliminary study of applying optical coherence tomography (OCT) for noninvasive diagnosis of osteonecrosis using an endoscopic probe based on a microelectromechanical (MEMS)

Abstract Grating plays an essential role in various optical systems owing to its unique dispersion properties. In recent years, there is increasing demand to miniaturize optical systems for a wide range of field applications. Therefore, the integration of diffraction grating with MEMS technology provides an efficient way to build truly miniaturized optical systems. Till now, MEMS diffraction gratings

Abstract Spatial pose estimation devices for mobile and cable-suspended robots have been rapidly developed. The HTC Vive sensor, which operates with swept laser beams, has aroused many researchers’ interest. We present experiments with a double pendulum robot equipped with the HTC Vive Tracker. A linear feedback controller ensured the tracking of pre-defined end-effector trajectories of various speeds

Abstract Different designs for contact lenses can result in insufficient oxygen permeability of the lenses. Moreover, the contact lens wearing schedule, replacement, lens care systems, and purchase methods are all important considerations for contact lens wearers. To evaluate the influence of tinted contact lenses with the pigment layer in different locations on the tear quality and ocular surface

Abstract The geometrical error caused pointing error is an inevitable problem in space satellite laser communication terminals which can affect the pointing accuracy of the APT (acquisition pointing and tracking) system greatly, in order to facilitate the assembling of the APT system and improve the performance of the laser communication system, the geometrical error sensitivity about the APT pointing

Abstract This study examined the effects of overnight orthokeratology (OK) on higher-order wavefront aberrations (HOA), axial length elongation, and accommodation. Low to moderate myopic subjects with healthy eyes wore OK lenses nightly for 9 months. Corneal topography wavefront aberrations and accommodation were measured approximately monthly. Linear mixed-effects models were used to examine the association

Abstract This study investigated the characteristics and location of the pigment layer of commercially available tinted contact lenses and evaluated ocular surface properties. The rub-off test and anterior segment Fourier-domain optical coherence tomography were used to analyze the pigment layer of the lenses. They also completed a rating questionnaire of subjective symptom perception after wearing

Abstract Wafer bonding is an attractive technology that can join homo/heterogeneous materials into one composite. It has a wide range of applications in the micro-electro-mechanical system (MEMS), integrated circuit, consumer and power electronics, micro/nanofluidics, etc. Since all devices on the same wafer are sealed and tested at wafer size, it brings lots of benefits compared with the component-level

Abstract Advances in astronomy led to the demand for measuring the spectra of multiple night sky objects simultaneously. Some of these Multi-Object Spectrographs use robotic systems that position optical fibers in the focal plane of the observing telescope. These systems rely on precise fiber placement in order to collect the light spectra of faint stars and galaxies. Here, we present how to design

Abstract In recent years, electromagnetic characteristics of metamaterials has aroused great interest because of innovative fundamental understanding as well as promising potential applications in optics, semiconductors, imaging, and sensing. We survey the state-of-the-art of spatially reconfigurable metamaterials in which electromagnetic Lorentz, Coulomb, and Ampere forces, as well as optical signals

Abstract This paper proposes an intelligent approach (fuzzy logic) for the design of external-cavity semiconductor lasers (ECLs) for better disturbance rejection. As a kind of nonlinear optical system, ECL output frequency is difficult to be stabilized by conventional methods. The fuzzy logic algorithm is preferred for ECLs stabilization, which could update parameters automatically. Suddenability to

Abstract The study investigates the effects of variables of laser-assisted turning (LAT) and conventional turning (CT) on machining performance of 45% volume fraction silicon carbide particle reinforced 2024 aluminum matrix composites (45 vol.% SiCp/2024Al). The process benefits of laser processing variables were analyzed by comparing the surface roughness, surface microstructure and residual stress

Abstract A wavelength switchable erbium-doped fiber laser was constructed based on an all-fiber Mach–Zehnder interferometer (MZI) comb filter. The MZI consisted of a fiber with two tapers. An L-band erbium-doped fiber was used as the gain medium, and 1557.92, 1563.2, and 1568.06 nm single-wavelength and dual-wavelength switchable lasers at 1558, 1563.7, and 1570.2 nm were realized by adjusting the

Abstract One of the primary challenges in advanced manufacturing (AM) is the lack of efficient optical metrics for ensuring quality control over the manufacturing process. Many current imaging techniques have excessive data requirements and require computationally intensive post-processing to effectively characterize various AM environments. Spatial frequency modulated imaging (SPIFI) addresses many

A transparent, conductive, smooth, and temperature sensitive thin films was fabricated and characterized in this paper. Silk fibroin could be processed into transparent thin films, which can act as ideal opto-electronic substrates. As pure silk fibroin film is nonconductive, ultra-long silver nanowires coating and platinum sputtering were used to strengthen its conductivity. Ultra-long nanowires were

Vein display device can significantly increase the success rate of intravenous injection. However, traditional vein display devices only contain near-infrared image information, which inevitably loses skin color information. In this article, a binocular microlens was fabricated by micro-fabrication technology. Then, a smart binocular microlens imaging system is set up. By this system, the near-infrared

In this paper, a rectangular magnetic fluid deformable mirror (MFDM) with dual-layer actuators is proposed, which is designed to improve the correction performance for full-order aberrations. Compared with the conventional adaptive optics system that uses two mirrors to configure as a woofer–tweeter system, the proposed MFDM combines the two mirrors into one by using a two-layer layout design of the

Marginal changes in geometrical dimensions due to temperature changes affect the performance of optical instruments. Highly dimensionally stable materials can minimize these effects since they offer low coefficients of thermal expansion (CTE). Our dilatometer, based on heterodyne interferometry, is able to determine the CTE in 10−8 K−1 range. Here, we present the improved interferometer performance

We present a novel method to accurately measure the flatness of a large flat. The method can be seen as a task-specific error correction of the laser tracker. Laser trackers are positioned at two specific measuring stations and measure the coordinates of the same sample points. The angular errors of the primary laser tracker are compensated with constraint information provided by an additional laser

Surface-enhanced Raman scattering (SERS) have numerous applications in areas such as analytical chemistry, biochemistry, and environmental science. However to manufacture SERS active substrates with good reproducibility and low cost is not easy, which hinder the SERS technology from being widespread in various applications. In this study, we developed a batch producible hot embossing 3D nanostructured

An erbium-doped fiber laser with all-fiber Mach–Zehnder interferometer (MZI) and tunable filter was proposed and experimentally demonstrated. In the designed fiber laser, 6 m C-band erbium-doped fiber was selected as a gain medium; the MZI comprised two waist-enlarged fiber bitapers. In the experiment, the laser threshold was 93 mW, whereas a switchable single-longitudinal-mode laser was realized within

The experimental results obtained with a ferrofluidic deformable mirror controlled by electro-magnet actuators are presented here. Using a step input through a single actuator, we obtained a steady-state settling time of 100 ms; however, different combinations of overdrive inputs can be used to decrease it to 25 ms. A new technique which consists of laying down an elastomer membrane, coated with an

A numerical method aimed to predict the optomechanical dynamics in micro- and nano-structured resonant cavities is introduced here. The rigorousness of it is ensured by exploiting the harmonic version of the transformation optics (TO) technique and by considering all the energy-transduction contributions of electrostriction, radiation pressure, photoelasticity and moving boundaries. Since our full-wave

A high-resolution automated optical inspection (AOI) system based on parallel computing is developed to achieve fast inspection and classification of surface defects. To perform fast inspection, the AOI apparatus is connected to a central computer which executes image processing instructions in a graphical processing unit. Defect classification is simultaneously implemented with Hu’s moment invariants

The reversible photostriction (photomechanical strain) in Ge35S65 chalcogenide thin film deposited by a solvent casting method has been monitored using a fiber Bragg grating (FBG) sensor. The shift in Bragg wavelength is used as a probing parameter to quantitatively measure the photoinduced strain arising because of structural modifications in these films under illumination. Exposure to band gap light

Photoacoustic spectroscopy has been used to measure optical absorption coefficient and the application of tens of wavelength bands in photoacoustic spectroscopy was reported. Using optical methods, absorption-related information is, generally, derived from reflectance or transmittance values. Hence measurement accuracy is limited for highly absorbing samples where the reflectance or transmittance is

We demonstrate fabrication of a high-quality factor lithium niobate double-disk whispering-gallery microcavity using femtosecond laser assisted ion beam milling. Using this method, two vertically stacked 30-µm diameter disks with a 200-nm gap are fabricated. With our device, an optical quality factor as high as 1.35 × 105 is demonstrated. Our approach is scalable to fabricate multiple disks on a single

This paper reports a micromirror-based real image laser automotive head-up display (HUD), which overcomes the limitations of the previous designs by: (1) implementing an advanced display approach which is able to display sharp corners while the previous designs can only display curved lines such as to improve the display fidelity and (2) Optimizing the optical configuration to significantly reduce

This article describes the 3D handheld profiling system composed of a stereo camera and an illumination projector to collect high-resolution data for close range of applications. Visual navigation approach is either based on feature matching or on accurate target, and the target-based approach was found to be more accurate if the 3D object has less texture on its surface. Block matching algorithm was

(2016). Editorial Board EOV. International Journal of Optomechatronics: Vol. 10, No. 3-4, pp. ebi-ebi.

A mixed light source generates various colors with the potential to adjust the intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the red, green, and blue (RGB) or hue, saturation, and lightness (HSL) color coordinates of a user’s selection. Mixed light sources are usually composed of primary-colored

Since computer controlled optical surfacing (CCOS) processes were proposed in the 1960s, many processes were developed for precision optics successfully. In this present work, a novel approach, the precessions process, is proposed and used for large segments fabrication. The removal function of the bonnet polisher based on velocity and pressure distribution, which are obtained from the geometry of

A 1.8-µm tunable multiwavelength thulium-doped fiber laser based on a hybrid filter is proposed. In the designed ring-cavity fiber laser, the filter consists of one Sagnac loop and one dual-pass Mach–Zehnder filter. In the experiment, the lasing threshold is 155 mW, and a continuously tunable and stable single-wavelength laser could be realized with a minimum tuning interval of 2.1 nm within a scope

Resist based lithographical techniques are widely applied for graphene processing. These resists can leave residues leading to parasitic effects that deteriorate the desired properties of graphene. This paper presents an experimental setup tailored for resist-free robotic processing of graphene with in-situ vision based control. A robust graphene detection and classification approach is presented applying

A numerical model and simulation relative to an optoelectrofluidic chip has been presented in this article. Both dielectrophoretic and electroosmotic force attracting the nano-sized particles could be studied by the diffusion, convection, and migration equations. For the nano-sized particles, the protein with radius 3.6 nm is considered as the objective particle. The electroosmosis dependent upon applied

In this article, we present a novel concept of inertial sensor, based on a linear encoder. Compared to other interferometric sensors, the encoder is much more easy to mount, and the calibration more stable. A prototype has been built and validated experimentally by comparison with a commercial seismometer. It has a resolution of about 10 pm/√Hz. In order to further improve the resolution, two concepts

An optical inspection platform combining parallel image processing with high resolution opto-mechanical module was developed for defect inspection of touch panel glass. Dark field images were acquired using a 12288-pixel line CCD camera with 3.5 µm per pixel resolution and 12 kHz line rate. Key features of the glass surface were analyzed by parallel image processing on combined CPU and GPU platforms

The propulsion of ferromagnetic objects by means of MRI gradients is a promising approach to enable new forms of therapy. In this work, necessary techniques are presented to make this approach work. This includes path planning algorithms working on MRI data, ferromagnetic artifact imaging and a tracking algorithm which delivers position feedback for the ferromagnetic objects, and a propulsion sequence

The aim of this article is to introduce an innovative algorithm for the calculation of the shift of the maximum reflectivity wavelength of a Fiber Bragg Grating experiencing an applied strain. An accurate and precise evaluation of the FBG spectrum displacement is crucial for determining the amount of the physical quantity inducing such perturbations. The proposed method is based on the Fast Fourier

We studied the lateral forces arising during the vertical indentation of the cell membrane by an optically trapped microbead, using back focal plane interferometry to determine force components in all directions. We analyzed the cell-microbead interaction and showed that indeed the force had also lateral components. Using the Hertz model, we calculated and compared the elastic moduli resulting from

A method and setup are proposed for trapping and detecting nanoparticles dispersed in a nanocomposite solution using periodically localized light generated by a subwavelength transmission grating. By numerical simulations, it is shown that there is an optimum duty ratio of the grating to produce the periodically localized light. Experimental results are presented for Au/γ-Fe2O3 composite nanoparticles

Optical whispering gallery mode resonators are important platforms to enhance and study various nonlinear frequency conversion processes. Stimulated Brillouin scattering is one of the strongest nonlinear effects, and can be successfully investigated using these platforms. In this article, we study the phenomenon of stimulated Brillouin scattering using a crystalline disk resonator. A fast scanning