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Optical coherence tomography (OCT) is an attractive tool for evaluating cartilage. We developed an OCT system that reconstructs and analyzes a three-dimensional (3D) OCT image by determining the cartilage surface and cartilage-bone boundary from the image taken with currently available OCT devices. We examined the usefulness of 3D renderings of OCT images. In a rat meniscectomized model, the tibia was harvested after 0, 2, 4, or 8 weeks (n = 6). We scanned 300 slices in the y-plane to cover a 4 × 3 × 6-mm section (x-plane; 10 µm × 400 pixels, y-plane; 10 µm × 300 pixels, z-plane; 12.66 µm × 500 pixels) of the medial tibial cartilage. The cartilage surface line and the cartilage-bone boundary were plotted semi-automatically. Slices from 300 two-dimensional (2D) sequential images were systematically and visually checked and corrected, as necessary. We set a region of interest in the cartilage and quantified the cartilage volume in the 3D image. The Osteoarthritis Research Society International (OARSI) histological score was also obtained. The cartilage volume determined using 3D OCT images was 0.291 ± 0.022 mm3 in the normal, 0.264 ± 0.009 mm3 at 2 weeks, 0.210 ± 0.012 mm3 at 4 weeks, and 0.205 ± 0.011 mm3 at 8 weeks. The cartilage volume significantly decreased at 4 and 8 weeks and was significantly correlated with the OARSI histological score (r = -0.674; P = .002). Although the 3D image information could be obtained from the 2D images, the 3D OCT images provided easier-to-understand information because the 3D reconstructed cartilage provided information about the smoothness of the surface, the area, and depth of the defect at a glance.

Optical Wireless Power Transmission (OWPT) is one of the technologies of wireless energy transfer. OWPT uses optical light source as an energy emitter, and solar panel as an energy detector. With current trends of availability of large laser power source at lower prices and sophisticated image recognition technologies, OWPT increases its attention. In order to obtain high energy transfer efficiency in OWPT, precise control of laser illuminating position is required. We apply co-axially aligned optical system of imaging function and laser beam steering function to satisfy the requirement. At the presentation, we will introduce our approach of OWPT.

The possibility of an areal density over 50 Gbit/in2 was examined in near-field phase-change recording. The disk structure was optimized to maximize readout signals under the land-and-groove recording condition at a tracking pitch of 160 nm. We also evaluated the signal crosstalk from adjacent tracks. Eye diagrams of 50.4 Gbit/in2 areal density were demonstrated using 1.5 NA optics and a GaN laser diode. The track pitch and linear bit density are 160 nm and 80 nm/bit, respectively. The transmission electron microscope (TEM) micrograph of recorded amorphous marks at an areal density of 50.4 Gbit/in2 is also presented.

An optoelectronic CMOS memory technology is proposed where photon induced floating body effect stimulates switching and hysteresis in the transistor. The floating body effect is induced by exceedingly few carriers generated by two photon absorption. In this paper we present the structure of proposing device and numerically validated the device by Atlas device simulator from SILVACO Corporation.

We proposed and demonstrated the effective method to measure the three dimensional position of fluorescent marker with using conventional fluorescence microscope. In this method the position information in focusing direction is recorded into blurring information. We confirmed this method has enough precision by using engineering specimen and also we have succeeded to measure chromatic aberration of imaging system.

Optical disk readout signals with a solid immersion lens (SIL) and the land-groove recording technique are calculated by use of a simplified vector-diffraction theory. In this method the full vector-diffraction theory is applied to calculate the diffracted light from the initial state of the disk, and the light scattered from the recorded marks is regarded as a perturbation. Using this method, we confirmed that the land-groove recording technique is effective as a means of cross-talk reduction even when the numerical aperture is more than 1. However, the top surface of the disk under the SIL must be flat, or the readout signal from marks recorded on a groove decays when the optical depth of the groove is greater than lambda/8.

From the viewpoint of electric device fabrication, we examined a SIMOX 3D sculpting method (Koonath, 2003) that three dimensionally integrate electric circuits and photonic circuits on an SOI substrate. We investigated buried optical waveguide structure underneath the silicon surface and defect characteristics on the surface of the substrate made by 8" size SIMOX 3D sculpting. As a result, we showed that balancing between no defects on the silicon surface and a formation of buried waveguide is achievable when the BOX by SIMOX 3D sculpting is continuous

The optical characteristics of a liquid-crystal (LC) panel with microdots on an electrode are investigated. Although 3 mum is larger than 1 molecule of LC material, microdots with a 3 microm diameter are sufficiently small to produce a smooth index profile. We use an electrode patterned in a new way to modulate the index profile of the LC panel, which allows us to modulate the optical phase of the passing light.

A novel approach to three-dimensionally (3-D) integrate nanophotonic and electronic devices in silicon is described. The method is based on the SIMOX (Separation by Implantation of OXygen) process, to realize three-dimensionally (3-D) integrated devices in a monolithic fashion. In this approach, photonic and electronic devices are realized on vertically stacked layers of silicon, separated from each other by a dielectric layer of silicon dioxide formed through the process of oxygen implantation. Opto-electronic integration is demonstrated by realizing photonic circuits in a subterranean silicon layer and Metal-Oxide-Semiconductor (MOS) transistors on a surface layer of silicon. Optical and electronic functionalities are thus separated into two different layers of silicon, paving the way towards dense three-dimensional opto-electronic integration. This has the significant advantage that photonic devices do not consume any of the expensive silicon real estate required for CMOS circuitry. The versatility of the technique of SIMOX 3-D sculpting in obtaining complex optical circuitry is also demonstrated by synthesizing a cascaded microdisk structure that may be utilized to tailor the passband characteristics of optical filters.

We proposed the phase-profile modulating device with microdots on the electrode of LC panel. The phase modulation profile corresponding with the profile of density modulated microdots on the electrode of the device, was demonstrated.

In this paper, fabrication of three dimensionally integrated nano-optical structures in silicon-on-insulator (SOI) substrates using the process of separation by implantation of oxygen (SIMOX) is reported. Buried rib waveguides with lowest ever loss with the SIMOX process, reported with the fabrication of vertically integrated structures using conventional lithography and etching process, demonstrate the capability to sculpt 3-D integrated optical devices.

We propose multi-layer near-field recording with using inner focus mode. The restricted conditions for multi-layer near-field recording are discussed from the viewpoint of both media structure and optical setup. One solution is presented for dual layer recording with a numerical aperture (NA) of 1.5 and a wavelength of 405 nm as a light source of GaN laser diode.In the proposed layer structure, a Nb2O5 material has been adopted as the intermediate layer because of its high refractive index, n = 2.4, in order to prevent the decrease of beam propagation that corresponds to NA>1. Almost the same signal characteristics can be obtained from both recording layers at the air gap of 40 nm. The adjustment of focusing position and the compensation of spherical aberrations have been implemented by the combination of an expander lens unit and a liquid crystal (LC) panel in the optical setup.

We demonstrated near-field recording with the combination of a GaN laser diode and a 1.5 NA objective lens. The realized linear bit density was less than 90 nm (corresponding to the areal recording density over 40 Gbit/in/sup 2/) regardless of using a small 1.0 mm-diameter super-hemispherical solid immersion lens (SIL). Further improvement of a near-field phase-change optical disk will enable a linear bit density of 80 nm or less. In this talk we shall also report the fabrication process of the plateau, and of the electrode on the SIL.

Recently, solid immersion lenses (SILs) have yielded a great interest in near-field optical data storage. However, convincing data on areal recording density have yet to be reported. The difficulty is attributed to the fact that an air-bearing slider needs to be kept optically contacted and also that a tiny SIL is vulnerable to aberrations caused by an air gap between a lens and a disk. The air-bearing system cannot easily achieve the condition above because its linear velocity changes the air gap. We have developed a new SIL device mounted on an actuator, which allows the air gap to be varied arbitrarily and enables optical contact independent of disk rotation. The obtained eyepattern of (l,7)-coded data on a phase-change disk demonstrates near-field recording over 1.2- numerical-aperture (NA).

The author proposes a method to identify the three-dimensional positions of fluorescent biomarkers by recording just two images. In the proposed method, the x and y positions of all fluorescent markers are recorded in the first exposure, and the z positions are obtained from a blurred image in the second exposure. The author has verified this method using a specimen with 1 μm deep grooves and applied it to measuring chromatic aberration and the separation between two biological probes in fluorescence in situ hybridization cells. The method offers the advantage of greatly reduced data storage requirements.

With a view to application to electric-device fabrication, the authors investigated a separation-by-implanted-oxygen (SIMOX) three-dimensional (3D) sculpting method [P. Koonath et al., Appl. Phys. Lett. 83, 4909 (2003)] that will integrate in three dimensions electric circuits and photonic circuits on a silicon-on-insulator substrate. The authors analyzed the defects in the first silicon layer for electric circuits and the second silicon layer for optical circuits made by SIMOX 3D sculpting. The authors found that a balance between an acceptable number of defects on the first silicon layer and the formation of a buried optical waveguide is achievable. The defect densities of the first silicon layer and the second silicon layer were 1.8×103∕cm2 and 5.0×107∕cm2, respectively.

We have fabricated a plasma-etched lens about three times larger than our previous design by using a novel selectivity control technique during transfer processes, and performed phase-change optical recording for the digital-video-recording (DVR)-blue format. We have fabricated an aspherical plasma etched lens using the selectivity control transfer technique.

Near-field optical recording was implemented on a pre-grooved phase-change disk by using a φ1 mm superhemispherical solid immersion lens (SIL) of 1.5 numerical aperture. The SIL unit was mounted on a two-axis actuator for enabling both gap-height and tracking controls. The gap height was precisely adjusted with a capacitance formed between the SIL and disk materials. Groove structures were fabricated on a glass substrate by a reactive-ion-etching (RIE) process and flattened with spin-on-glass (SOG) coating for obtaining reliable push-pull tracking error signals. The phase-change layer stack was optimized by a vector diffraction analysis in order to maximize evanescent coupling at the gap height as small as 50 nm. A bit density of 80 nm was demonstrated on the land of a pre-grooved disk at the wavelength of 407 nm.

Near-field recording for the disc mastering process was realized. A high-numerical-aperture (NA) objective (NA=1.4) composed of an aspherical lens and a solid immersion lens (SIL) was driven by an air pad and a piezotransducer. The gap between the SIL and the glassmaster was controlled by a new gap detection method using the totally internally reflected beam from the bottom surface of the SIL. In the near-field operation, the gap was maintained at 100 nm with a residual error of ±4.8 nm. In the DC exposure with a laser beam of 413 nm, a narrower groove structure could be formed almost at the inverse rate of NA expansion. In the read-only memory (ROM) exposure with an eight to fourteen modulation plus (EFM+) signal, signal bottom jitter values of 9.8% for an 18 GB disc and 10.9% for a 20 GB disc were obtained.

A bit density of 125 nm was demonstrated through near-field phase-change (PC) optical recording at the wavelength of 657 nm by using a supersphere solid immersion lens (SIL). The lens unit consists of a standard objective and a φ2.5 mm SIL. Since this lens size still prevents the unit from being mounted on an air-bearing slider, we developed a one-axis positioning actuator and an active capacitance servo for precise gap control to thoroughly investigate near-field recording. An electrode was fabricated on the bottom of the SIL, and a capacitor was formed facing a disk material. This setup realized a stable air gap below 50 nm, and a new method of simulating modulation transfer function (MTF) optimized the PC disk structure at this gap height. Obtained jitter of 8.8% and a clear eye-pattern prove that our system successfully attained the designed numerical-aperture (NA) of 1.36.