Three-dimensional nanostructure fabrication has been demonstrated by 30 keV Ga⁺ focused-ion-beam chemical-vapor-deposition (FIB-CVD) using a phenanthrene (C₁₄H₁₀) source as a precursor. Microstructure plastic arts is advocated as a new field using micro-beam technology, presenting one example of micro-wine-glass with 2.75μm external diameter and 12μm height. The deposition film is a diamondlike amorphous carbon. A large Young's modulus that exceeds 600 GPa seems to present great possibilities for various applications. Producing of three-dimensional nanostructure is discussed. Micro-coil, nanoelectrostatic actuator, and nano-space-wiring with 0.1μm dimension are demonstrated as parts of nanomechanical system. Furthermore, nanoinjector and nanomanipulator are also fabricated as a novel nano-tool for manipulation and analysis of subcellular organelles.

We report the low-temperature bonding of a lithium niobate (LiNbO₃) chip with gold (Au) thin film to a silicon (Si) substrate with patterned Au film for hybrid-integrated optical devices. The bonding was achieved by introducing the surface activation by plasma irradiation into the flip-chip bonding process. After the Au thin film (thickness: 500 nm) on the LiNbO₃ chip (6 mm by 6 mm) and the patterned Au film (thickness: 2 μm) on the Si substrate (12 mm by 12 mm) were cleaned by using argon (Ar) radio-frequency (RF) plasma, Au-Au bonding was carried out in ambient air with applied static pressure (~50 kgf). The LiNbO₃ chips were successfully bonded to the Si substrates at relatively low temperature (< 100 °C). However, when the bonding temperature was increased to be greater than 150 °C, the LiNbO₃ chips cracked during bonding. The tensile strength (calculated by dividing the total cross-sectional area of the initial, undeformed micropatterns) of the interface was estimated to be about 70 MPa (bonding temperature: 100 °C). It was sufficient for use in optical applications. These results show the potential for producing highly functional optical devices and for low-cost packaging of LiNbO₃ devices.

In this paper, we propose a solution for simple, fast and easily controllable way of tuning silicon gratings using Micro Electro Mechanical Systems (MEMS) to deform the grating itself. Basically the idea is to deform mechanically a silicon grating using electrostatic actuators, enabling pitch tuning over a large proportion (more than 50% is easily achievable with our approach). Moreover we can change the spacing of individual layers within the grating. A theoretical analysis and numerical simulations are presented and a first prototype is fabricated. Bragg gratings, springs and actuators are realized by silicon micro/nano machining on a silicon platform enabling full integration and passive alignment of all optical components. Applications range from ultra-sensitive displacement sensors, to telecommunications and biology.

Networks of non-linear oscillators have a potential to simulate physiological functions of living system. Expected similarity in spatiotemporal behavior was obtained in between the inter-cellular concentration pulse in Ca²⁺ triggered by f-sec laser irradiation and the current pulse propagation along excitable non-linear electrode pairs triggered by electric stimulus. These resemblances are owing to the same dynamical rules governing both biological and electrochemical systems.

Recently, a method for fabricating planar arrays of optical microtoroid resonators with quality factors greater than 500 million was developed. These devices have previously demonstrated Raman and OPO lasing and radiation pressure induced oscillations. When immersed in an aqueous environment, these devices are able to maintain their ultra-high Q factors by operating in the visible wavelength band, enabling very sensitive chemical and biological detection. The fabrication and optical properties of these devices will be described. These devices have performed both chemical and biological detection. Systems which have been detected include D₂O in water and a variety of biological molecules. Sensitivity limits will also be discussed.

We propose an all-optical fiberscopic endoscope for medical diagnosis by using a MEMS optical scanner with the wavelength-division multiplex approach. An infrared light of 1.3 microns was used for medical inspection through the endoscope fiber, and it was scanned over the tissue of interest by using a MEMS scanning mirror. The mirror was electrostatically operated not by using external voltage line but by co-located photovoltaic cell, which generated operation voltage from another input light of 1.5-micron-wavelength. The entire sensor head (fiber, beam splitter, photovoltaic cell, and MEMS chip) was encapsulated in a Pyrex glass tube of 5 mrn outer diameter. Drive voltage of 5 V was obtained by the optical modulation, and the MEMS scanner chip operated at 300 Hz resonance for optical scan angle of 10 degrees. In this paper, we present the MEMS device structure, optical system, and preliminary imaging of human skin tissue by the optical coherent tomography.

Insufficient vision information such as occlusion and low resolvability is one of the important issues that limit the micromanipulation and microassembly. In this paper, we proposed the active vision system that can interact with the environment by changing optical system parameters such as spatial position, orientation and focus plane. As an optomechatronic system, the proposed system integrates a pair of wedge prism, a scanning mirror, a deformable mirror and off-the-shelf optics. The compact double wedge prisms can change the view direction, however the aberration induced by wedge prisms can be corrected by deformable mirror. Combining with a scanning mirror, active optical system can observe the micro object in different view. Owing to the orthogonality of the Zernike polynomials, the proposed deformable mirror control algorithm can correct the aberration in each Zernike mode instead of controlling each actuator, which simplifies the control issue of deformable mirror. The preliminary experiment setup was built, and initial experiments were demonstrated to investigate the validity of the concept of the proposed system.

Aligning of multiple micro-optical components is required for many systems composed of arrays of multiple lens elements, apertures, and filters. Methods of aligning two such wafers using mechanical features are discussed here. Alignment features include binary holes and posts, or grooves and ridges. With the circular holes or rectangular grooves etched into the two wafers, the mating pins or ridges are formed on both sides of a separate element to set both the lateral and vertical positioning. Grayscale technology allows for the printing of V-grooves and V-cones onto any substrate material over a wide range of aspect ratios. When integrated with cylindrical (fiber) or spherical (ball lens) mechanical features, this allows for accurate positioning. Some techniques allow for repositioning as well as disassembly and reassembly. The designs are kinematic or nearly kinematic. The paper discusses tolerances on mating components, and the associated precision of the overall alignment.

In this paper, we developed a new mounting head system for a microchip such as flip chip. The proposed head system consists of a macro/micro positioning actuator for stable force control. The macro actuator provide the system with a gross motion while the micro device yields fine tuned motion to reduce the harmful impact force that occurs between very small sized electronic parts and the surface of a PCB(printed circuit board). In order to show the effectiveness of the proposed macro/micro mounting system, we compared the proposed system with the conventional mounting head equipped with a macro actuator only. A series of experiments were executed under the mounting conditions such as various access velocities and PCB stiffness. As a result of this study, a satisfactory voice coil actuator as the micro actuator has been developed , and its performance meet well the specifications desired for the design of the microchip mounting head system and show good correspondence between theoretical analysis and experimental results.

In this paper, two image processing approaches are presented, which are used to gain vision feedback for automatic nanohandling inside a Scanning Electron Microscope (SEM). The first one is a vision-based force measurement that makes use of an active contours tracking algorithm for real-time tracking of the bending line of micro- and nanoobjects. With this algorithm, it is possible to calculate applied forces in real-time with respect to the image acquisition time. This approach is validated using a piezo-resistive force sensor. In a second experiment the force applied to a Si nanowire (d ≈ 470 nm) is measured. The second visual measurement approach deals with the calculations of depth information inside an SEM by means of stereoscopic images. Therefore, a new 3D-imaging system that uses a stereo algorithm based on a biologically motivated energy model is proposed. The system provides a sharp and high density disparity map in sub-pixel accuracy and a 3D-plot for the user.

A robotic-based microassembly process has been successfully applied to the construction of a novel micro-mirror design for use in optical switching. This paper is devoted to the description of the microassembly process used to construct the 3D micro-mirror. The microassembly process is based upon the PMKIL (Passive Microgripper, Key and Inter-Lock) assembly system. Details of the assembly process include, the methodology to construct the micro-mirror, the design of the micro-mirror parts, and the design of the tools (microgrippers) that are mounted to the robot to handle the micro-parts. The results of the assembly process are presented, along with examples of prototype 3D micro-mirrors. The entire 3D micromirror consists of a novel electro-static rotary motor, onto which the 3D mirror structure is assembled. The 3D micro-mirror is used as a building element for 1 N optical switching systems and for N×M optical crossconnects.

Advances in microelectromechanical systems (MEMS) technology are enabling the design and fabrication of new class of deformable mirrors (DM) for adaptive optics (AO). This paper presents a MEMS DM design that is suitable for a large range of applications. More than 7.5 μm of stroke has been demonstrated for this DM with 125 V drive. Other minor design variations have shown 1.63 μm step responses of 120 μs and 140 μs rise and fall times with only a 36 V drive. The DMs have excellent optical quality of 6-20 nm rms that varies with temperature only 0.56 nm/°C peak-to-valley.

A backlight unit (BLU) of TFT-LCD is composed of a light source, a light guiding plate (LGP), prism sheets, diffusive sheets and a reflective sheet. The LGP is a very important component in backlight panel (BLP). Generally, Polymethyl methacrylate (PMMA) material is chosen to make the LGP by using injection molding technique. In this research, Microelectromechanical Systems (MEMS) and hot-embossing technology are applied to fabricate the integrated LGP with the microstructures of double-sides and a reflective film. The new BLU will be only one integrated LGP without any other optical components, which are a reflective sheet, a diffusive sheet, and a prism sheet in BLU, and it can save the space and the fabrication cost. In future, the integrated LGP could make the display thinner and brighter for LCD application.

We have demonstrated the technology to fabricate a polymer sub-micrometer structure by two-photon-induced photopolymerization. Since photopolymerization resin contained conventional laser-dye and polymer host, we could obtain optically active polymer structures such as laser microcavities and photonic crystals. We have been investigating the polymer material for use it as an optical high gain medium, and found that a spherical macromolecule, called as dendrimer, could be especially useful for our applications. Observed optical response attributes to the site-isolation effect of dendrimer, which limits cluster formation and intermolecular energy transfer, promising a high level of optical gain. We utilized these effects for two-photon induced laser lithography, which is often sensitive to the energetically quenching problems. From the viewpoint of the extension of the polymer material to the optical device application, it is important to consider the device dimensions with a scale of sub-micromeres. We investigate both the material functions in the molecular scale and controlling the device structure for desired applications such as a polymer DFB and photonic crystal.

Wavelength-selective switches (WSSs) and wavelength-selective cross connects (WSXCs) enable flexible, intelligent wavelength-division-multiplexed (WDM) networks as well as reduce the operating cost. In a 1×N WSS, the wavelengths from the input port can be independently switched to any of the N output ports. WSXC allows switching of optical signals at wavelength level between N input ports and N output ports. Most of the WSS and WSXC reported to date are realized by free-space optical systems with either micro-electro-mechanical-systems (MEMS) or liquid crystal (LC) beamsteering array, or by silica-based planar lightwave circuits with cascaded 2×2 thermal optical switches. In this paper, we report on the approach to monolithically integrate the WSS and WSXC on a single silicon-on-insulator (SOI) chip. Optical waveguides, microgratings, parabolic reflectors, as well as MEMS active switching micromirrors are fabricated on the same substrate using a one-step etching process. We have successfully fabricated a 1×4 WSS with CWDM (20- nm) channel spacing on a 1×2-cm² chip, and achieved a fiber-to-fiber insertion loss of 11.7 dB, and a switching time of 0.5 msec. The monolithic 4x4 WSXC is realized by integrating four 4×1 WSSs and four 1×4 multi-mode interference (MMI) splitters on the same wafer. No fiber connections or external splitter are required. The fabricated 4×4 WSXC has a chip area of 3.2×4.6 cm² and an insertion loss of 24 dB, including a 6-dB splitting loss. The WSXC supports unicast, multicast, and broadcast functions. The devices can be further scaled to DWDM (100-GHz) channel spacing.

We have already proposed a new system concept, Generation Free Platform (GF-PF), where the system can continue to grow and reconfigure to correspond with rapid changes in business conditions. In our concept, a multi-stage modular switch and a stackable system with optical interconnection are key features that can achieve a scalable and flexible system. By using our ultra small optical transceiver (PETIT) and high-Δ low-diameter MMF in the optical interconnection, fiber assembly area can be much smaller than that of a conventional design.

Reconfigurable optical add/drop multiplexers (R-OADMs) are indispensable devices in wavelength division multiplexing (WDM) network systems, since they can be used for dynamically wavelength routing and for replacing any failed OADM unit. Here, we propose a photonic integrated R-OADM device based on silicon photonic crystal (PhC) slab waveguides, which is controlled through thermo-optic effect. The R-OADM device was composed of a tunable wavelength multiplexer/demultiplexer and a 2×2 optical switch, which were both formed with Mach-Zehnder interferometers (MZIs). The device was compact with a net footprint of 500 μm × 140 μm, excluding its electrode pads. The dropping central wavelength of the R-OADM can be tuned through thermo-optic effect, and the output port of the drop signal can be selected between the THROUGH and DROP ports with the 2x2 optical switch. A maximum 10.8 nm dropping wavelength tuning was obtained with a heating power of 0.9 W. The 3-dB channel-dropping bandwidth was 5 nm and the extinction ratio at the dropping wavelength for the port THROUGH was as high as 40 dB. The tuning response speed was about 100 μsec.

We report on a channel drop filter with a mode gap in the propagating mode of a photonic crystal slab that was fabricated on silicon on an insulator wafer. The results, simulated with the 3-dimensional finite-difference time-domain and plane-wave methods, demonstrated that an index-guiding mode for the line defect waveguide of a photonic crystal slab has a band gap at wave vector k = 0.5 for a mainly TM-like light-wave. The mode gap works as a distributed Bragg grating reflector that propagates the light-wave through the line defect waveguide, and can be used as an optical filter. The filter bandwidth was varied from 1-8 nm with an r/a (r: hole radius, a: lattice constant) variation around the wavelength range of 1550-1600 nm. We fabricated a Bragg reflector with a photonic crystal line-defect waveguide and Si-channel waveguides and by measuring the transmittance spectrum found that the Bragg reflector caused abrupt dips in transmittance. These experimental results are consistent with the results of the theoretical analysis described above. Utilizing the Bragg reflector, we fabricated channel dropping filters with photonic crystal slabs connected between channel waveguides and demonstrated their transmittance characteristics. They were highly drop efficient, with a flattop drop-out spectrum at a wavelength of 1.56 μm and a drop bandwidth of 5.8 nm. Results showed that an optical adddrop multiplexer with a 2-D photonic crystal will be available for application in WDM devices for photonic networks and for LSIs in the near future.

UV curable novel silicone polymers, Nano-Hybrid Silicone (NHS), having high thermal stability, low-shrinkage and high transparency were developed. The optical waveguide could be fabricated by direct UV exposed patterning method, since photolithograph using NHS could be available. Two kinds of NHS for optical waveguide were developed, one is for optical waveguide on Si substrate and the other is for film optical waveguide. The optical losses of these waveguides measured by cut-back method at 850 nm were significantly low, and indicated 0.05 dB/cm (Si substrate waveguide) and less than 0.1 dB/cm (film waveguide) respectively. Heat durable tests of these waveguides were carried out for surface packaging technologies under lead free solder melting temperature, and no significant changes of optical loss were observed. Especially with the waveguide on Si substrate, the optical loss increase was less than 0.02 dB/cm without changing of shape after the heat resistance test at 270 degrees Celsius for 10 minutes. UV durable tests of these waveguide were also carried out for the adhesion using UV curable resin on electric board. No change was observed with optical waveguide capability after UV exposure (10 J/cm² at 365 nm). Furthermore, value movement of optical loss was small at preliminary tests of heat-cycling and reliability under the high temperature and humidity condition according to Telcordia specification. Due to their various processes durability, the waveguides made with novel silicone-based material are expected to be suitable for practical uses.

This paper presents a reference pattern-based two-dimensional (2D) measurement method. In the method, surface structure patterns obtained from a four-beam laser interference lithography (LIL) process were used as reference patterns for 2D measurement. The reference patterns played the role of 2D rulers in the measurement. The nano resolution of the measurement was achieved by feature counting and pattern matching techniques. A statistical analysis indicates that the measurement made by pattern matching has the advantage of averaging noise. For reference pattern-based 2D measurement, the reference patterns can be regular or irregular. This approach is potentially useful for micro and nano manipulation in the processes of assembly, packaging and manufacturing of nano and micro-systems when relative nano positioning accuracy is required.

This paper describes a new approach to realize a bidirectional repeater suitable for sensor networks with absolute time synchronization, and discuss propagation delay measurements of an experimental bidirectional repeatered system. A time-shared quasi-bidirectional linear repeater, that enables to the direction of signal flow to be changed. It uses a unidirectional EDFA, an optical router module composed of magneto-optic components and a delay fiber. The repeater has realized identical propagation delay for both directions of signal flows and attained multipath interference free amplification of optical packet signals for absolute time synchronization and sensing. A 50.078 km bidirectional repeatered line varied its propagation delays by 1.2 ns for both directions of signal flow with laboratory temperature change. Nevertheless, the experimental setup has not detected the propagation delay difference between both directions of signal flows that exceeded +/- 30 ps. This means that highly accurate absolute time synchronization will be feasible using bidirectional transmission system equipped with the time-shared quasi-bidirectional linear repeaters.

Backlight unit (BLU) comprises light sources, light guiding plate (LGP), prism sheets, two diffusive sheets and reflective sheet. Following the development of the thin-film liquid crystal display (LCD), many researchers have devoted to improve the BLU and then make it lighter, thinner and brighter. The LGP is a very important component in backlight unit (BLU). In General, Injection molding technology is utilized to fabricate the LGP, which is made of polymethyl methacrylate (PMMA). In this research, the integrated LGP with the microstructures of double-sides and a thin-film of enhanced reflection is fabricated by using Microelectromechanical Systems and hot-embossing techniques. A new BLU will be simplified to use only one guiding light component without using any optical sheets. The integrated LGP can eliminate three types of the optical components including reflective sheet, diffusive sheet, prism sheet in BLU; therefore, the space and the fabrication cost are saved. In future, the integrated LGP could make the display thinner and brighter for TFT-LCD application.