Abstract: This invention provides a photodetector for weak light and a weak light detection system including the photodetector for weak light the photodetector for weak light is comprised of a substrate on which an integrating read circuit including a PIN photodiode or an APD and an FET is mounted, wherein the entire assembly is mounted while separating the substrate from a ground potential without grounding the substrate, such a photodetector for weak light can reduce noise and ensure a high enough sensitivity enough to be able to discriminate the number of photons.

Abstract: This invention provides a method for manufacturing a circuit for photon number counting without destroying a FET within the circuit by manufacturing a photodetector for weak light, the photodetector for weak light comprising a circuit on a substrate, the circuit comprising light detection means and a field effect transistor (FET), the method comprising: a light detection means connection step; an FET electrode-to-substrate electrode connection step; an external electrode connection step, a light detection means-to-gate connection step.

Abstract: The present invention provides a photodetector for weak light that can release charge from the circuit without increasing capacity; the present invention being characterized by a photodetector for weak light that has a charge release means which permits the photodetector for weak light of the present invention to avoid increasing its capacity because it does not require a reset transistor integrated with the photodector, rather the charge reset means of the present invention lowers mounting capacity by removing itself from the circuit after it releases the charge.

Abstract: The present invention provides a photodetector for weak light that can prevent noise from impurities, prevent electrodes from disconnecting from the substrate, and can be easily cooled; the present invention further provides a photodetector for weak light that can count the number of photons; the present invention solves the above problems by using an ultraviolet light transparent substrate on the photodetector for weak light.

Abstract: Quantum source coding apparatus for communication of quantum information comprising: a quantum state preparation device for converting input messages into block messages; a coding device for producing coded signals by compressing the block messages prepared by the quantum state preparation device; and an output device for outputting the coded signals produced by the coding device.

Abstract: The present invention provides a method of estimating ingredients of liquefaction products of coal or its analogues from a resonance spectrum thereof obtained using their solid state 13C nuclear magnetic resonance spectrometer. The method comprises the first step of obtaining a resonance spectrum of coal or its analogues using a solid state 13C nuclear magnetic resonance spectrometer, the second step of determining distribution of various types of carbon having different linkage types which constitute the molecular structure of the coal or its analogues, and the third step of estimating ingredients of liquefaction products of the coal or its analogues on the basis of the determined carbon distribution.

Abstract: A container for organism sample made of soft thermoplastic synthetic resin having a cylindrical body with a bottom and a cap whch is airtightly put on a mouth of the body. The cap has a cap portion to cover the mouth and a stopper portion to be inserted into the mouth. The cap cannot come off from the body by virtue of the above double-engagement-construction. In the second invention, a container further has a plurality of annular ribs provided at an outer wall of a body portion of the body near the mouth. Thus, the container can be used as a plug for a test tube and the like and there can be avoided a trouble of taking the wrong container.