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We have been developing original MEMS-based X-ray optics toward future astronomical missions such as a planetary exploration mission. In this paper, we report results on the first X-ray irradiation test for a 2-stage MEMS-based optic. The obtained FWHM of the focusing image is 13±2 arcmin. However, an occultation effect and a deformation accuracy possibly affect a reduction of effective area.
Using nano-imprint technology we have developed a rotary diffraction grating scale, which is used for micro rotary encoding. The off-center error between the center of the trough-hole for a rotational axis and the center of the high-precision micro-pattern on the periphery of the scale is less than 3 µm because we are able to shape the through-hole and the grating pattern simultaneously. The use of...
Potentials of the transparent polyimide (PI) substrate were investigated for a possible biological cell culture sheet. Stromal marrow cells (OP9) were used to test the cell culture characteristics, and the OP9 cell culture was compared on three kinds of polymer films of transparent PI, parylene (PA), and polyetheretherketone (PEEK). Microtrenches with the width of 5 µm and the depth of 5 µm were fabricated...
In this study, photochemical polishing based on a nonadiabatic optical near-field etching to sapphire substrate is studied. A sapphire substrate with an initial roughness of Ra=6.00 nm was polished by 100 Pa Cl2 gas atmosphere under laser irradiation for 60 minutes, and smoothened into Ra= 1.91 nm. Due to the Gaussian intensity distribution in the laser beam section, there was in-plane distribution...
This paper presents a nanoelectromechanical system (NEMS) variable transmission attenuator based on a gap variable subwavelength grating with a low drive voltage. An array of parallel-plate actuators is deployed over a through hole. The transmitted light intensity decreased from 63.3% to 46.5% with a drive voltage of 3.2 V at a wavelength of 775 nm.
A moving-magnet-type raster-output 2D MEMS scanner with a rotation-angle detector has been developed. To realize high precision and low temperature dependence, we propose the detector composed of four Hall sensors. By operation the outputs of the four Hall sensors, we enhanced the sensitivity and linearity of the detector, and realized the high precision detector. The fabricated detector achieved...
This paper presents a gimbaled MEMS scanning mirror especially developed for adaptive raster scanning in a novel 3D-ToF laser camera. Substantial quasi-static deflections of ±10° are provided by vertical comb drives in vertical direction in contrast to resonant horizontal scanning of the 2.6×3.6mm elliptical mirror at 1600Hz and 80° FOV. To guarantee the full reception aperture of effective 5mm a...
This paper reports experimentally measured data of a tunable whispered gallery mode photonic dual-disk resonator (DDR) with enhanced quality factors. The measured result shows 25 nm of free spectrum range (FSR) and the data has a good agreement with three dimensional (3-D) finite difference time domain (FDTD) simulation results. Thermo-optics effect enables the resonance peak tunability of DDR throughout...
A microring resonator was fabricated in LiNbO3 substrate by annealed proton exchange (APE) method. Measurement results show that thermal annealing is necessary to improve the performance of the channel waveguides. The measured extinction ratio is approximately 13dB. By making use of Cr film as electrodes, a tunability of 2 pm/V is obtained by applying 150V.
We report for the first time a broadband variable optical attenuator employing a side-polished single-mode optical fiber integrated on an electrowetting-on-dielectric platform. This in-line fiber optic device has the advantage of no moving mechanical parts and lends itself to miniaturization.
The micro-channel device for passing the supercontinuum light across the liquid channel is developed. For the accurate alignment of the optical fibers, the bias spring with the reversely tapered profile is newly introduced realizing the high transmission ratio. Infra-red absorption spectrum is measured for obtaining the molecular information. When the water is introduced in the liquid channel, the...
We propose a simple fabrication method for a dual-axis polymer MEMS mirror made of negative photoresist SU-8 containing magnetic nanoparticles as a magnetically driven actuator. The proposed mirror is driven by magnetic attractive force using external magnetic field. So, it doesn't need complex wiring patterns and can simply fabricate by photolithography only. For evaluation of drive characteristics...
Silicon-organic hybrid (SOH) integration can extend the capabilities of silicon photonics by combining silicon-on-insulator (SOI) waveguides with functional organic cladding materials. This enables energy-efficient electro-optic modulators and ultra-compact phase shifters. We review recent progress in SOH integration, discussing both fundamental device concepts and experimental demonstrations.
By integrating microdisk optical cavities with MEMS and NEMS, we achieve on-chip interferometric motion sensing with better than 1 fm/Hz½ precision and 1 GHz bandwidth. These transducers are less than 20 um in size, stable, self-aligned and fiber connectorized. Silicon-on-insulator (SOI) fabrication, operation at standard telecom wavelengths and design separating optical and mechanical parts enable...
This research proposes a silicon rim for an optically flat mirror and a vertical comb actuator in a silicon nitride (SiN) microscanner. A wafer-level vacuum packaging was also successfully implemented for large angular deflections with low driving voltage. Radius of curvature (ROC) of a SiN mirror of 1 µm-thickness and 1 mm-diameter was measured to be 0.357 m. Optical experiment showed optical tilt...
This work report the modified Plasmon Ruler equation for quasi-ordered nanoislands using deformable nanoplasmonic membrane that able to modulate interstitial gap between neighboring nanoislands. Depending on interstitial gap, the plasmon resonance wavelength shift was achieved by averaging the plasmon resonance shift of individual nanoislands that reflects the size distribution of nanoislands. This...
This work reports the artificial compound eye using fractal zone plate (FraZP) arrays. Spherically arranged optical elements (ommatidia) of compound eyes facilitate wide field-of-view (FOV) imaging. However, due to the lack of curved image sensors, it was difficult to integrate hemispherical shape of an artificial compound eye with commercially available flat image sensors. FraZP gives sufficient...
Characteristics and alignment tolerances of a MEMS Alvarez lens are studied. Results show that the lens can adjust its focal length substantially with small lateral displacements of its constituent elements along the x axis. Meanwhile, it is also revealed that the lens performance degrades with the increasing displacements. The lens is most sensitive to the misalignment along the y direction. Normalized...
A thin-film nanostructured Lüneburg lens with guidance condition correction has been fabricated by patterning a slab of silicon-rods on silicon-on-insulator wafer, and has been characterized using a near-field scanning optical microscope.
Next generation of multi-object spectrographs (MOS) in astronomy will use MEMS-based programmable slit masks. Large micromirror arrays with 2048 tiltable micromirrors were fabricated using bulk and surface micro-machining, and wafer level bonding for the assembly. Micromirror size is 100µm × 200 µm and they exhibit very good surface flatness. Mirror architecture as well as a large mechanical tilt...
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