Japan Atomic Energy Research Institute

Mitsubishi Chemical Industries Limited

Yoichiro Maruyama

Takashi Arisawa

Masaaki Kato

Masaharu Kaneko

Akira Ohzu

Koreyuki Shiba

Katsuaki Akaoka

Youji Suzuki

Hitoshi Ono

Toshio Niwa

Seiichi Imahori

Hiromitsu Kiriyama

Kazumi Iwamoto

Tsuyoshi Nakayama

Akira Sugiyama

Hitohsi Ono

A remote particle counter comprising a pulsed laser generator, laser light emitting optics, scattered light collecting optics, a high-sensitivity two-dimensional photo detector as a scattered light detecting portion having a fast gating capability such as a CCD camera, and a control and measure system, wherein suspended fine particles forming aerosols in the atmosphere which are far away from the site of laser emission are illuminated with laser light, the resulting backward scattered light from the individual fine particles is detected as image, and the number and size distribution of the suspended fine particles are measured at a remote site.

Remote particle counter for remote measurement of the number and size distribution of suspended fine particles in the atmosphere

The efficiency of wavelength conversion of laser light can be improved by allowing incident laser light to pass through nonlinear optical crystals a multiple of times. In converting the wavelength of laser light to generate second- and higher harmonic waves, a returning mirror, a polarizer and nonlinear optical crystals are combined and the rotation of polarized light is utilized to allow the incident laser light to undergo multiple passes through the nonlinear optical crystals so that it can be converted in wavelength with higher efficiency.

Method for changing a wavelength of a laser light

The wavefront of laser light as it propagates through a medium is controlled so that not only the inherent aberrations in the wavefront of the laser light itself but also the aberrations that are progressively caused by passage of laser light through the medium are effectively corrected to achieve long-distance propagation of the laser light through the medium.

Method of enabling laser light to propagate through a medium over long distance by means of controlling its wavefront

The compensation amount of the pressure for keeping the index of refraction of the gas constant is calculated on the basis of the pressures and the temperatures that have been measured at different time. Only the pressure of the gas will be varied in accordance with the calculated compensation value of the pressure, whereby the index of the gas can be maintained constant and the oscillation frequency can be kept constant as the consequence. The pressure corresponding to a desired sweeping oscillation frequency is also calculated using the measured pressures and temperatures. The pressure of the gas is varied on the basis of the result of calculation. Synchronously with the variation of the pressure of the gas, the cavity length and the angle of the frequency selecting element are compensated.

Apparatus and method of stabilizing oscillation frequency for single

A method of producing a small expansion of laser light, in a pulse laser apparatus, including producing a small preliminary laser light by pumping a laser medium, and then, after an appropriate time lag, then pumping the preliminary laser medium at a higher intensity than the first pumping, thereby producing a laser light which is smaller in beam expansion than in the case where a preliminary pumping is not performed. The laser light which is smaller in beam expansion is due to the population inversion occurring in a small beam expansion part of pulse laser light obtained by the preliminary pumping.

Method of producing a small beam expansion of laser light

A method is, herein, disclosed for separating a specific isotope from a mixture of isotopes by first irradiating the isotope mixture with a highly monochromatic laser light that resonates only with the energy level of the specific isotope so as to increase its chemical activity and then bombarding said specific isotope with a molecule containing highly reactive atoms so as to form a spatially separated compound rich in the specific isotope.

Method of separating isotopes

There is herein, disclosed a dye laser including a container for a dye solution and a pumping energy source coupled thereto, said dye solution containing a perimidone dye formula (I): ##STR1## wherein R.sup.1 is a hydrogen atom, an alkyl group, a trifluoromethyl group, an alkoxycarbonyl group, an alkoxycarbonylalkyl group, an aralkyl group or a phenyl group; R.sup.2 is an optionally substituted alkoxycarbonyl group, a cyclohexyloxycarbonyl group, tetrahydrofurfuryloxycarbonyl group, an aryloxycarbonyl group, a benzyloxycarbonyl group, an acyl group, a cyano group or an optionally substituted carbamoyl group; R.sup.3 and R.sup.4 which may be the same or different are each a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aralkyl group or an aryl group.

Dye laser

A process is, herein, disclosed for separating a particular isotope from a mixture of different isotopes by selective excitation and ionization of the particular isotope with a single laser beam, said process comprising heating the mixture, converting the resulting atomic vapor to a highly directional atomic beam by suitable means, causing said atomic beam to travel through a vacuum, crossing the atomic beam with a high-intensity laser beam having a specific wavelength, selectively exciting the particular isotope with a first photon having that specific wavelength while the other isotopes remaining in the ground state, allowing the excited isotope to absorb a second photon to be excited to a virtual energy level, causing the so excited isotope to absorb a third photon to ionize said isotope, and recovering the ionized isotope by use of an electric or electromagnetic field.

Process for separating an isotope from a mixture of different isotopes

A dye laser comprising a container retaining a dye solution for laser and an energy source for pumping connected to the container, the dye solution containing a pyrazoloazaxanthenoisoquinolinone dye.

Growing community of inventors

Ibaraki, Japan

Yoichiro Maruyama