尾松 孝茂

We demonstrate efficient degenerate four-wave mixing in a laser injection-seeded solid dye laser. Phase-conjugate energy of as much as 140 times the total energy injected externally into the phase conjugator was extracted. Moreover, efficient phase-conjugate energy was obtained in the broad wavelength region from 558 to 567 nm. (C) 2000 Optical Society of America OCIS codes: 190.5040, 190.4380, 140.3280.

This article studied an efficient phase conjugator by degenerated four wave mixing in laser injection seeded solid dye laser. Dye laser pumped by the same frequency-doubled Q-switched Nd:YAG laser was used as a probe and forward-pump laser for four wave mixing. For an efficient phase conjugation, the probe beam passing through the solid dye was retro-reflected by the mirror which enabled the reflected probe beam to overlap spatially the intra-cavity counter-propagating pump beams.

Tunable phase conjugation by intracavity degenerate four-wave mixing was demonstrated in an injection-seeded solid dye laser. The maximum efficiency was observed at the four-wave mixing laser wavelength of 564 nm. For efficient phase conjugation, the probe beam passing through the solid dye were reflected by two mirrors, which enable the reflected probe beam to overlap the counter propagating pump beams.

A novel method for determining mode power distribution in a two-mode fiber illuminated by an offset beam by measuring the near field pattern on the test fiber endface is developed. This method utilizes the different field symmetries of the fundamental and the second order modes. Coupling efficiencies from a quasi-Gaussian beam to the fundamental and the second order modes in a two mode fiber were measured by the new technique for various offset launching conditions, and were in good agreement with the theoretical ones.