Yasuaki Inoue

DC Analysis of Non-Linear Circuits using Solution Tracing Circuits

The amount of tryptophan (Trp) available for transport from plasma into the brain was estimated in patients with major depression before treatment for 4 weeks with a 5-HT potentiating tricyclic antidepressant (TCA), amitriptyline (n = 21) or clomipramine (n = 17), or a selective 5-HT uptake inhibitor, citalopram (n = 14) or paroxetine (n = 27). The ratio in plasma of Trp to the sum of the other large neutral amino acids (LNAA) was significantly inversely correlated with improvement on TCA, and patients with ratio Trp/LNAA below the mean improved significantly more than patients with a higher ratio but with comparable serum steady-state drug levels. The Trp concentration was a bit stronger inversely correlated with improvement on 5-HT uptake inhibitors than the ratio Trp/LNAA, and patients with Trp level below the mean improved significantly more than those with a higher level but with comparable serum steady-state drug levels. Plasma amino acid variables may be a useful tool for increasing the efficacy of antidepressant treatment.

High-Power, 790 nm, Eight-Beam AlGaAs Laser Array with a Monitoring Photodiode

A high-power, 790 nm, eight-beam individually addressable AlGaAs laser array on 50 µm centers with a monitoring photodiode has been developed for high-speed data transfer in optical memory systems. The maximum output power of each element is over 80 mW. When eight elements are simultaneously operated at 20 mW in APC (Automatic Power Control) mode using the one-beam monitoring control, the total light output variation is less than 7% at a heatsink temperature between 10 and 50°C.

Fundamental transverse mode 100-mW semiconductor laser with high reliability

A 100 mW high-power AlGaAs laser with the current-blocking regions near the facets and a long cavity length has been developed. The length and the channel width of the current-blocking region, and cavity length were examined in order to obtain a high-output power. As a result, a stable fundamental transverse mode operation is obtained up to 180 mW, and maximum output power is 230 mW under CW operation. Stable operation under 100 mW of output power was confirmed for more than 2000 hours at 60 C.

Geometric distortion compensation of printed images containing imperceptible watermarks

This work proposes a digital watermarking system using camera phones and high quality printed images, which contain imperceptible watermarks. The system compensates for geometric lens distortion in order to extract the imperceptible watermarks correctly from the camera-captured images.

Monolithic Four-Beam Semiconductor Laser Array with Built-in Monitoring Photodiodes

A four-beam semiconductor laser was developed in which a monolithic array of four individually addressable GaAlAs high power lasers and four integrated Si photodiodes for monitoring the light output power of laser beams are housed in a single package. The main specifications are as follows; output power per beam, 40 mW; wavelength, 830 nm; and monitoring current at 30 mW, 100~200 Thermal analysis by numerical simulation was carried out and compared to experimental values observed during simultaneous operation of the multiple elemental lasers. The operating lifetime is estimated to be more than 10,000 hrs at room temperature.

Fundamental transverse-mode 150-mW semiconductor laser for an SHG light source

A highly reliable, 150 mW high-power semiconductor laser that oscillates at a wavelength of 860 nm has been developed. This device has a 0.7 jim thick p-cladding layer, a 900 jim long cavity length, and current-blocking regions near the cavity facets for high output power and high reliability. Stable, fundamental transverse mode and single longitudinal mode operation were obtained up to 230 mW, and the maximum output power was 350 mW under CW operation. Stable operation under 150 mW at 50°C was confirmed for more than 2000 hrs.

100 mW, Four-beam Individually Addressable Monolithic ALGaAs Laser-diode Arrays

Four-beam individually addressable monolithic AlGaAs laser-diode arrays have been developed in which each laser element can emit over 100 mW of output power in single-mode operation. The structural features of this laser include current-blocking regions near the facets and a long cavity length to obtain higher power, as well as a cBN heatsink and a 70 micrometers - thick laser chip to improve thermal crosstalk between laser elements. The maximum output power of each laser element is about 200 mW and the lasing wavelength is about 834 nm. Thermal crosstalk between 100 micrometers -spaced neighboring elements is only 1.0% at 100 mW.

Development of network digital camera and its performance evaluation

This paper first describes the architecture of the network digital camera. Then, a real-time streaming system using the network digital camera, an access point (AP) and a digital photo album is proposed and evaluated. The evaluation is based on the characteristics of the packet transmission time, which depends on two varying parameters, namely, the condition and population of the wireless environment.