Pseudo 2-transistor active pixel sensor using an n-well/gate-tied p-channel metal oxide semiconductor field eeffect transistor-type photodetector with built-in transfer gate

In this paper, a pseudo 2-transistor active pixel sensor (APS) has been designed and fabricated by using an n-well/gate-tied p-channel metal oxide semiconductor field effect transistor (PMOSFET)-type photodetector with built-in transfer gate. The proposed sensor has been fabricated using a 0.35 μm 2-poly 4-metal standard complementary metal oxide semiconductor (CMOS) logic process. The pseudo 2-transistor APS consists of two NMOSFETs and one photodetector which can amplify the generated photocurrent. The area of the pseudo 2-transistor APS is 7.1 × 6.2 μm². The sensitivity of the proposed pixel is 49 lux/(V·s). By using this pixel, a smaller pixel area and a higher level of sensitivity can be realized when compared with a conventional 3-transistor APS which uses a pn junction photodiode.     

The effect of body bias of the metal-oxide-semiconductor field-effect transistor in the resistive network on spatial current distribution in a bio-inspired complementary metal-oxide-semiconductor vision chip

Complementary metal-oxide-semiconductor (CMOS) vision chips for edge detection based on a resistive circuit have recently been developed. These chips help in the creation of neuromorphic systems of a compact size, high speed of operation, and low power dissipation. The output of the vision chip depends predominantly upon the electrical characteristics of the resistive network which consists of a resistive circuit. In this paper, the body effect of the metal-oxide-semiconductor field-effect transistor for current distribution in a resistive circuit is discussed with a simple model. In order to evaluate the model, two 160 × 120 CMOS vision chips have been fabricated using a standard CMOS technology. The experimental results nicely match our prediction.     

Multipole analysis of the radiation from near-field optical probes

We experimentally and theoretically analyze the radiation emitted from subwavelength-sized apertures in near-field optical probes. By decomposing the experimentally obtained radiation patterns into vector spherical waves, we describe the fields in terms of a series of multipole sources. We fit polarization-resolved angular intensity distributions, measured as far as 150 degrees from the normal, with dipole, quadrupole, and octupole radiation. We find that the magnetic and the electric dipole components are dominant but that the interference terms between dipoles and higher-order poles are not negligible. This result can be used as the basis for understanding near-field optical interactions and images.     

Phase-shift studies of the imprisonment lifetime of cadmium(5 3P1) and the effect of the addition of noble gases

The imprisonment lifetime of Cd³P₁), measured by a phase-shift method was found to depend on the modulation frequency at 534 K. This frequency dependence is considered to correspond to the non-exponential decay after a pulsed excitation, and was analyzed on the basis of Milne's diffusion theory. The effect of the addition of noble gases was also examined, and it was found that noble gases scarcely deactivate the Cd(³P₁) atoms at 458 K.     

Application of the atomic Faraday effect to the trace determination of lead

The atomic Faraday effect has been applied to the trace determination of lead in NBS Orchard Leaves, human blood, and volcanic ashes. Suspensions of powder samples and diluted whole blood are directly pipetted into a graphite tube atomizer. Spectroscopic and practical features are discussed of the atomic Faraday effect of lead. The inherent feature of insensitivity to background scattering makes the present technique suitable for practical analysis. The problem associated with loss of transmitted optical energy caused by non-atomic species was overcome by a correction method. Consequently, the present technique enabled us to perform rapid analyses, gave a detection limit of 5 × 10^?11 g and fair accuracy, at least satisfactory for practical analysis. Some problems arise from residue build-up in the atomizer.