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We demonstrated the rapid and nondestructive observation of structural defects in SiC wafers by full-wafer photoluminescence (PL) imaging under below-gap excitation. The use of visible light emitting diode arrays as an excitation source is essential to the simplification of an optical system and the light excitation covering the whole wafer. We were able to observe the defect-related intensity patterns similar to those obtained by conventional laser-scanning PL mapping. The measurement time of the PL imaging was more than fifty times faster than that of the PL mapping.

We have demonstrated variable dispersion compensation by using a virtually imaged phased array (VIPA) to overcome the small dispersion tolerance in 40-Gb/s dense wavelength-division multiplexing (WDM) transmission systems. By utilizing the periodical characteristics of VIPA compensators, we performed simultaneous dispersion compensation in a 1.28-Tb/s (40-Gb/s/spl times/32 ch; C band) short-haul transmission and confirmed that only two VIPA compensators and one fixed dispersion-compensating fiber are required for a large transmission range of 80 km. This performance can greatly reduce the cost, size, and number of compensator menus in a 40-Gb/s WDM short-haul transmission system. In addition, we achieved 3.5-Tb/s (43-Gb/s/spl times/88 ch; C and L bands) transmission over a 600-km nonzero dispersion-shifted fiber by using VIPA compensators. Although channel-by-channel dispersion compensation is required due to the larger residual dispersion slope in long-haul transmission, the periodical characteristics of the VIPA compensators offer the advantage of considerably reducing the number of different modules required to cover the whole C (or L) band. An adequate optical signal-to-noise ratio, which was the same for all channels, was-obtained by using distributed Raman amplification, a gain equalizer, and a preemphasis technique. We achieved a Q-factor of more than 11.8 dB; (BER

There are strong demands to expand captioned broadcasting for TV news programs in Japan. However, keyboard entry of captioned manuscripts for news programs cannot keep pace with the speed of speech because Japanese use ideographic characters. To realize simultaneous subtitling of Japanese news programs, a real-time speech recognition system to handle broadcast news transcription has been developed. Experiments showed that word recognition error rate of the system for studio announcer speech is 2.8% in the real-time recognition and the error rate can reduce to 0.8% by manual correction with an average total delay of 10.4 seconds.

Although not commonly seen in Japan, the incidence of leptospirosis reported in 2014 was the highest in the past 6 years. It is important to consider leptospirosis among patients who traveled to Okinawa, Japan, and to keep in mind Jarisch–Herxheimer reaction when administering antimicrobial agents to patients with leptospirosis. A 59-year-old Japanese man with a history of hypertension presented with a complaint of fever and watery diarrhea. He climbed mountains, got lost accidentally and drunk 2 l of fresh water in the swamp in Okinawa, Japan 2 weeks prior to admission. Physical examinations showed blood pressure 129/89 mmHg, heart rate 112/min, respiratory rate 30/min, temperature of 38.5°C and oxygen saturation of 97% on room air. His bilateral palpebral conjunctivas were significantly injected with jaundice. The patient had tenderness to bilateral thighs …

Summary form only given. We performed 3.5-Tbit/s (43-Gbit/s /spl times/ 88 ch) 600 km transmission in the C- and L-bands by using virtually imaged phased array (VIPA) variable dispersion compensators. An adequate OSNR, which was the same for all the channels, was obtained by using distributed Raman amplification (DRA), a gain equalizer (GEQ), and a pre-emphasis technique. VIPA variable dispersion compensators can thus effectively overcome the small dispersion tolerance and temporal dispersion changes of dense WDM terabit systems. We achieved a Q-factor of more than 11.8 dB (BER < 10/sup -17/ with FEC) for all 88 channels.

Objective: Televised images are the most common stimulus for provoking photosensitive seizures in photosensitive persons. To inhibit photosensitive seizures in photosensitive persons who do or do not have epilepsy, the authors sought nonpharmacologic methods for reducing the levels of photic stimulation of televised images. Background: The authors found two types of pathophysiologic mechanisms (wavelength-dependent and quantity of light–dependent mechanisms) for photoparoxysmal responses (PPR). Methods: The authors tested two different types of optical filters, one reflecting long-wavelength red light selectively, which stimulates a wavelength-dependent mechanism, and the other absorbing light in the visible spectrum evenly (neutral density filters). Inhibiting effects of optical filters were studied by conventional intermittent photic stimulation (IPS) using strobe light and novel photic stimulation using flashing cathode ray tubes (CRT). Results: Both filters individually inhibited PPR insufficiently (less than 50%). Compound optical filters, composed of both types of filters, can inhibit the PPR, approximately 90% for IPS and 95% for photic stimulation with CRT. These compound optical filters do not destroy chromaticity of emissions from the television’s CRT. Conclusions: These compound filters may be useful to prevent seizures induced by television in photosensitive persons.

Chromatic dispersion compensation using a virtually imaged phased array is described. This method has advantageous features: continuously variable dispersion over a /spl sim/4000 ps/nm range, simultaneous compensation of over 50 WDM channels with 100 GHz spacing, and potential for small packaging.

The resolution limitation of integral photography (IP) is analyzed. Estimating the resolution of IP measured at the viewpoint, we derive the optimum width of the aperture or lens. It is shown that the resolution of aperture-plate IP is lower than conventional two-dimensional displays, even with an optimum design. When the ideal lens is utilized, however, lens-array IP can provide a three-dimensional display that is free from any discontinuous change of images that occur with the observer’s movement and with the same resolution that conventional two-dimensional displays feature.

Based on the fact that a great majority of cells in the middle temporal (MT) area of the macaque respond to movement of luminance contours with directional selectivity, this area has been thought to be concerned with the analysis of visual motion. However, objects can be discriminated from the background not only by differences in luminance but also by differences in color. It is possible that color signals are also used for motion analysis in MT. In the present study, we examined whether MT cells respond to movement of a pattern composed of pure color-contours. Using a color TV system, a moving color bar was displayed on a uniform background whose color was opponent with that of the bar. The main bar/background color combination we examined was magenta/cyan. Yellow/blue and cyan/magenta combinations were also examined for some cells. The response of MT cells to movements of opponent-color stimuli was recorded while the bar/background luminance ratio was changed from 1/10 to 10/1. In half of 89 cells tested in 3 monkeys, the response decreased considerably (disappeared completely in some cells) at a luminance ratio close to the human equiluminous condition. In the other half, a directional response persisted at any bar/background luminance ratio, though the response decreased to a varied extent (30-90% of the maximum response) near the ratio 1 (human equiluminous condition). The average magnitude of the equiluminous response to the magenta/cyan stimulus for the overall population was about 35% of the maximal response when the length of the bar (0.5 degrees in width) and the movement amplitude were set to be optimal for individual cells, i.e. smaller than 15 degrees and 10 degrees of visual angle, respectively. This fall to 23% when the bar length and movement amplitude were limited to 2 degrees. The same cell responded to pure color-contours of yellow/blue as well as of cyan/magenta combinations. Thus, MT can detect the direction of movement of pure color-contours, although the sensitivity is less than for luminance contours.