Abstract: A carbon isotope analysis method, including the steps of: generating carbon dioxide isotope from carbon isotope; feeding the carbon dioxide isotope into an optical resonator having a pair of mirrors; applying irradiation light having an absorption wavelength of the carbon dioxide isotope into the optical resonator; adjusting a relative positional relationship between the mirrors so that an optical axis of the irradiation light and an optical axis of light generated by the etalon effect are not matched; measuring the intensity of the transmitted light generated by resonance of carbon dioxide isotope excited by the irradiation light; and calculating the concentration of the carbon isotope from the intensity of the transmitted light. An optical resonator that can be suppressed in the parasitic etalon effect, and a carbon isotope analysis device and a carbon isotope analysis method, by use of the optical resonator, are provided.

Abstract: A light generator including a light source, an optical switch that controls ON/OFF of light from the light source, and a mirror that reflects light from the optical switch and sends the light back to the optical switch. A light generator less in residue in fitting of a ring-down signal, and a radioactive carbon dioxide isotope analysis device and a radioactive carbon dioxide isotope analysis method, by use of the light generator are provided.

Abstract: Provided is a carbon isotope analysis device including a carbon dioxide isotope generator provided with a combustion unit that generates gas containing carbon dioxide isotope from carbon isotope, and a carbon dioxide isotope purifying unit; a spectrometer including optical resonators having a pair of mirrors, and a photodetector that determines intensity of light transmitted from the optical resonators; and a light generator including a single light source, a first optical fiber that transmits first light from the light source, a second optical fiber that generates second light of a longer wavelength than the first light, the second optical fiber splitting from the first optical fiber and coupling therewith downstream, a first amplifier on the first optical fiber, a second amplifier on the second optical fiber, different in band from the first amplifier, and a nonlinear optical crystal.

Abstract: Provided is a carbon isotope analysis device including a carbon dioxide isotope generator provided with a combustion unit that generates gas containing carbon dioxide isotope from carbon isotope, and a carbon dioxide isotope purifying unit; a spectrometer including optical resonators having a pair of mirrors, and a photodetector that determines intensity of light transmitted from the optical resonators; and a light generator including a single light source, a first optical fiber that transmits first light from the light source, a second optical fiber that generates second light of a longer wavelength than the first light, the second optical fiber splitting from the first optical fiber and coupling therewith downstream, a first amplifier on the first optical fiber, a second amplifier on the second optical fiber, different in band from the first amplifier, and a nonlinear optical crystal.

Abstract: A carbon isotope analysis device including a carbon dioxide isotope generator provided with a combustion unit that generates gas containing carbon dioxide isotope from carbon isotope, and a carbon dioxide isotope purifying unit; a spectrometer including an optical resonator having a pair of mirrors and a photodetector that determines intensity of light transmitted from the optical resonator; and a light generator including a light source, a splitter that splits light from the light source, a focusing lens that focuses light from the splitter, and a mirror that reflects light from the focusing lens and sends the light back to the light source via the focusing lens and the splitter. A carbon isotope analysis device improved in stability of a light source and a carbon isotope analysis method by use of the analysis device are provided.