Yasuo Horiuchi

New Laser Emission from NH3 Optically-Pumped by TE–CO2 Laser

Nineteen new laser lines have been found from NH3 pumped by a TE–CO2 laser. These lines span the wavelength range from 20.9 to 148.7 µm. Assignments are made on 17 lines and three of them are ascribed to stimulated Raman scattering. Two lines are left unassigned.

New Far Infrared Laser Emissions from D2CO and H2CO Optically-Pumped by a TECO2 Laser

H2CO and D2CO were optically-pumped by a TE CO2 laser and found to generate 7 and 64 new far infrared (FIR) lines, respectively. Most of the previously-reported D2CO cw FIR lines were also produced well. With an intracavity low-pressure cw CO2 gain cell, these previously reported cw FIR lines were found to oscillate efficiently. A well-developed cascade laser action and the oscillation of the cw FIR lines are the characteristic properties of a formaldehyde FIR laser pumped by a TE CO2 laser. The origin of these properties is discussed, and it is suggested that a large electric dipole moment along the symmetry axis and small pump offsets probably play an important role.

Tunable te-CO2 laser-pumped formaldehyde far-infrared lasers: Offsets, assignment, and superfluorescence

Sixty and three absorption transitions in D2CO and H2CO, respectively, have produced a number of far infrared laser lines when they are pumped by an etalon-tuned TE-CO2 laser. Almost all the absorption transitions pumped previously by a free runing TE-CO2 laser have been efficiently pumped by the etalon tuned CO2 laser and found to have offset within ±500 MHz from the line-center of the relevant CO2 pump lines. 22 (1) absorption and 63 (4) emission lines of D2CO (H2CO) are assigned. Some of these lines have generated superfluorescence. In paticular, the D2CO 319-μm line pumped by CO2-9P(32) delivered an output energy of approximately one half that of the well-known D2O 66-μm. It is shown that a large electric dipole moment and an appreciable amount of fractional population in the lower level of the pump transition of this line are responsible to the superfluorescence.

Two color oscillations of TE-CO2 laser and applications to two photon process of optically pumped FIR laser

We have developed the resonance system which is able to operate a TE-CO2 discharge tube in two color emission source. The two color source is excellent in pumping efficiency, spacial overlap and time synchronization of the two emission CO2 lines.We indicate that the competitive operation of the two emissions is well explained by a simple model.When a TE-CO2 laser operates at the total pressure of below half atmospheric pressure, we make clear in this work that the operation of a TE-CO2 laser forms “depression” like hole burning, with regards to the J of the upper laser level by J-J collisional relaxation during the laser emission.As an example of the two-photon source, two-photon pumping of NH3 and FIR emissions are given in this paper.

The study of the changes in cyclic nucleotides and the arachidonate metabolism via lipoxygenase affecting the respiratory function caused by swimming in severe asthmatic children

The basic defect in bronchial asthma appears to be an altered state of the bronchial tissues with hypersensitivity to a number of different trigger stimuli. Our previous study reported that an exercise gave a stimulation of the enzyme system that oxygenates arachidonic acid and the effect of exercise was expressed by the increased activation of the lipoxygenase system according to the degree of severity of asthmatic children. On the other hand, it has been known that swimming can not induce an attack of asthma even in severe asthmatic subjects, but the pathophysiology of the effect of swimming are still not fully understood. The present study was carried out t o determine whether the changes in FEVI.o caused by swimming was affected in correspondence with the changes of metabolism in the HETE resulting from the additions of arachidonate. Swimming was not followed by a fall in FEVI., with greater than 15% decrease in 12 severe asthmatic children. The decrease in PEFR and o, greater than 15% developed in only 2 of 12 asthmatic children after swimming, respectively. It has been suggested that cyclic AMP plays a central role in the regulation of the release of mediators. Swimming did not have the effect of the marked decrease of cAMP levels and inversely gave the stimulation of the increase in cAMP in 10 of 12 asthmatic children. The effect of swimming stimulus on the arachidonic acid was compared with that of the resting state in the same subjects. The increased formation of HETE and HPETE in leucocytes and platelets caused by swimming were shown in 5 of 1 1 asthmatic children, respectively, but the decrease in the lipoxygenase activity was smaller than that of the running stimulus. These results suggested that swimming might not influence the decrease of respiratory function by several mechanisms which would suppress the decrease in the lipoxygenase activity in accordance with the effect of the increase in CAMP, because there was a high correlation between the liberation and stimulation of histamine to activate the lipoxygenase pathway and the decrease of cAMP level.