Hideo Hirose

Intracavity pumped far-infrared lasers by TE CO2 laser.

A novel compact FIR laser system was constructed. The FIR laser cavity was placed inside the resonator of a pump TE CO2 laser. With this system, FIR laser actions in D2O and CH3OH were observed. Five new lines were found in CH3OH.

Mode Characteristics of TEA CO2 Laser Using an Unstable Resonator

An output spectrum of the TEA CO2 laser was observed with the use of a confocal Fabry-Perot interferometer. In output pulses, four or five longitudinal modes were found and they were oscillating independently. To obtain single mode oscillation, a Ge flat mirror or a butadiene absorption cell as a mode selector was placed in the unstable cavity. It was possible to determine the frequency of a single mode by using the Fabry-Perot interferometer.

Forced CO2 Laser Oscillation by Injection of a Weak External Optical Signal

A forced or frectuency locked oscillation is obtained even below threshold when a weak singleline of a CO2 laser is externally injected into a Q switched CO2 1aser system. For such a regenerative optical amplifier, the input power is amplified by a factor of 106. Without a dispersive element, a single line oscillation is obtained in the range of P(10) to P(32) and R(28) to R(14) of the 10.4 µm band transition for various external signals. The amplification mechanism of the input signal is explained by the assumption that the quantum noise and the external signal are amplified in the same manner, and by the exchange of the noise for the input power. Experimental results agree well with the theoretical results which are derived from the quantum mechanical Langevin equations.