Current medical imaging technologies allow visualization of tissue anatomy in the human body at resolutions ranging from 100 micrometers to 1 millimeter. These technologies are generally not sensitive enough to detect early-stage tissue abnormalities associated with diseases such as cancer and atherosclerosis, which require micrometer-scale resolution. Here, optical coherence tomography was adapted to allow high-speed visualization of tissue in a living animal with a catheter-endoscope 1 millimeter in diameter. This method, referred to as "optical biopsy," was used to obtain cross-sectional images of the rabbit gastrointestinal and respiratory tracts at 10-micrometer resolution.

In Vivo Endoscopic Optical Biopsy with Optical Coherence Tomography

A display panel and a display device are provided. The display panel comprises a central region and peripheral regions. The peripheral regions are provided at two opposite ends of the display panel and have a first curvature; the central region is provided between the two opposite ends of the display panel and has a second curvature; and the second curvature of the central region is smaller than the first curvature of the peripheral regions.

Display panel and display device

Electro-optic and Acousto-optic Laser Beam Scanners

Provided herein are electronic devices including arrays of printable light emitting diodes (LEDs) having device geometries and dimensions providing enhanced thermal management and control relative to conventional LED-based lighting systems. The systems and methods described provide large area, transparent, and/or flexible LED arrays useful for a range of applications in microelectronics, including display and lightning technology. Methods are also provided for assembling and using electronic devices including thermally managed arrays of printable light emitting diodes (LEDs).

Thermally Managed LED Arrays Assembled by Printing

This paper describes the experimental and theoretical studies of an anomalous optical beam deflection phenomenon based on electrooptic effect and space-charge-controlled electrical conduction. In the experiment, a large deflection angle of 250mrad (=14.3°) has been observed by applying ±250V to a 0.5‐mm-thick KTa1−xNbxO3 crystal with a short interaction length of 5.0mm. The crystal has a rectangular shape with uniform electrodes and there is no prism shape involved which is a common geometrical shape of crystal, electrode, or ferroelectric domain in the conventional electro-optic deflectors. The operating principle is investigated and it is found that the space-charge-controlled electrical conduction in the crystal plays an essential role in this deflection phenomenon. The electrical conduction is carried by electrons injected from the Ohmic contact of the electrode with the crystal. The injected electrons induce the space-charge effect and the electric field becomes nonuniform between the electrodes. The...

Space-charge-controlled electro-optic effect: Optical beam deflection by electro-optic effect and space-charge-controlled electrical conduction

An electro-optic beam deflector with unprecedented performance is demonstrated. A full deflection angle of 250mrad (=14.3°) has been achieved by applying only ±250V to a 0.5-mm-thick KTa1−xNbxO3 crystal with a short interaction length of 5.0mm. The operating principle is investigated and the origin of the deflection phenomenon is attributed to a nonuniform electric field induced by space-charge-controlled electrical conduction in the crystal.

Wide-angle, low-voltage electro-optic beam deflection based on space-charge-controlled mode of electrical conduction in KTa1−xNbxO3

We propose a new beam scanning model that is applicable to electrooptic materials with electron traps. With this model, we can achieve both high-speed operation and wide-angle scanning, because the operating speed is limited not by the electron mobility but by the frequency limit of the electrooptic effect of the materials. The voltage dependence of the scanning angle at 100 kHz using a KTa1-xNbxO3 crystal is consistent with the property predicted by the proposed model.

https://iopscience.iop.org/article/10.1143/APEX.4.111501/pdf

New Beam Scanning Model for High-Speed Operation Using KTa1-xNbxO3 Crystals

An electro-optical element capable of efficiently increasing a beam deflection and consisting of a simple structure, the element comprising an electro-optical crystal (11) having an electro-optical effect, an electrode pair consisting of an anode (12) and a cathode (13) to generate an electric field within the electro-optical crystal, and a power supply for applying a voltage between the electrode pair so as to generate spatial charge within the electro-optical crystal. The above arrangement can provide a large deflection angle, that is quick in time-wise change and cannot be realized with a conventional electro-optical crystal prism, using a simple structure at a low applied voltage.

Electro-optical element

We fabricated cylindrical varifocal lenses with fast responses by using the strong Kerr effect of KTa(1-x)Nb(x)O(3) (KTN) single crystals. We observed focus shifts of up to 87 mm with the assistance of a 250 mm focal length lens, which corresponds to a focus shift from infinity to 720 mm by the KTN lens itself. The response time was as fast as 1 μs. We also present a simulation method for calculating refractive index distributions in KTN single crystals, which is essential when designing the lens. The method is characterized by the strain contribution, which has not conventionally been typical of electro-optic simulations. We used this method to explain the refractive index modulations that are characteristic of the varifocal lenses.

Jun Miyazu

Papers

Wide-angle, low-voltage electro-optic beam deflection based on space-charge-controlled mode of electrical conduction in KTa1−xNbxO3

Space-charge-controlled electro-optic effect: Optical beam deflection by electro-optic effect and space-charge-controlled electrical conduction

New Beam Scanning Model for High-Speed Operation Using KTa1-xNbxO3 Crystals

Electro-optical element

Fast response varifocal lenses using KTa(1-x)Nb(x)O3 crystals and a simulation method with electrostrictive calculations.