Abstract: A nanofabricated logic device, operable at multiple (more than two) logic levels comprises asymmetrically coupled quantum point contacts provided with respective sources and drains and a coupling region between gate electrodes. The quantum mechanical carrier wavefunction in the region of QPC1, 2 is spatially asmmetric with alternate quantised energy levels lying either in QPC1, or QPC2, so that by changing the energy level, the conductance of the device can be switched between multiple stable conductance levels. The device can be used to provide a multilevel output switched in response to terahertz pulses provided by an array of optical detectors.

Abstract: Superconductized electronic devices, such as a Josephson junction device, or superconductized optical devices represented by a light emitting and receiving devices of semiconductor laser are available using semiconductor materials which normally have no superconducting characteristics. The devices can operate by controlling the behavior of a Cooper pair in an active region which is formed in the semiconductor in advance using the penetrating phenomenon of the Cooper pair caused in the semiconductor proximate to the superconductor.

Abstract: A field effect transistor and a ballistic transistor using semiconductor whiskers each having a desired diameter and formed at s desired location, a semiconductor vacuum microelectronic device using the same as electron emitting materials, a light emitting device using the same as quantum wires and the like are disclosed.

Abstract: A semiconductor light-emitting device includes a plurality of semiconductor rods, each of which has a pn junction. The semiconductor rods are formed on a semiconductor substrate such that the plurality of semiconductor rods are arranged at a distance substantially equal to an integer multiple of the wavelength of light emitted from the semiconductor rod. With such devices, various novel optical devices such as a micro-cavity laser of which the threshold current is extremely small and a coherent light-emitting device having no threshold value can be realized.

Abstract: An information recording medium for suppressing the interferences of bits before and after reproduction and improving the optical resolution with saturable absorber 102 disposed adjacent or in an information recording medium layer 103. The recorded information is detected only from a region having a predetermined optical intensity or more of the focused spot so that minute information bits smaller than the optical resolution can be reproduced to improve the recording density of an optical disk drive drastically.

Abstract: A device structure is provided for optical modulation using a quantum interference effect in an excited state of electron-systems. The optical modulation is performed by causing the effect of modulation on the excited state of electron-systems represented by excitons to be executed on light via the state in which the light and the excited state of electron-systems represented by the excitonic polaritons are coupled.

Abstract: An optical device has multilayer films formed by periodically laminating a number of layers each comprising at least two kinds of optical crystal thin films (f.sub.n, g.sub.n) having different refractive indices onto a substrate. The multilayer films include a semiconductor material having a large non-linear optical coefficient as a composing material and have artificial optical anisotropy. Since the multilayer films of the optical device have a large non-linear coefficient and optical anisotropy, a non-linear phenomenon such as second-harmonic generation or the like can be efficiently caused.

Abstract: A device structure is provided for optical modulation using a quantum interference effect in an excited state of electron-systems. The optical modulation is performed by causing the effect of modulation on the excited state of electron-systems represented by excitons to be executed on light via the state in which the light and the excited state of electron-systems represented by the excitonic polaritons are coupled.