Engineering topics

Feldman, B. J.

Publications and source records attributed to Feldman, B. J..

4 records

NASA NTRS1973

Selective reabsorption leading to multiple oscillations in the 8446-A atomic-oxygen laser.

Laser oscillation of atomic oxygen at 8446 A occurs in four closely spaced lines with peculiar intensity ratios, all detuned from the atomic center frequencies of the three fine-structure transitions. These anomalies are caused by the selective reabsorption of resonance radiation from the lower laser level by ground-state oxygen atoms. The selectivity results from the fact that the velocity distribution of the laser levels is considerably wider than that of the ground state, because of the dissociative mode of production of excited oxygen atoms. Possible extension of this mechanism to the atomic-hydrogen system is discussed.

Feld, M. S.↗

NASA NTRS1973

Interactions among multiple lines in the 8446-A atomic-oxygen laser.

The atomic-oxygen laser oscillates at four closely spaced frequencies on the gain profile of the 8446-A fine-structure transitions. A set of experiments is reported which studies the competition among these four lines by suppressing one of them. The results are explained on the basis of the interaction of laser lines oscillating on Doppler-broadened transitions sharing a common lower level.

Domash, L. H.↗

NASA NTRS1972

Laser-induced line-narrowing effects in coupled Doppler-broadened transitions. II - Standing-wave features.

Previous theoretical results on the influence of a laser on the line shape of a coupled transition (laser-induced line narrowing) have been restricted to the case where the laser is detuned from the center of its atomic gain profile or is in the form of a traveling wave. The present paper extends these results to the case where the laser is an intense standing-wave field tunable to the center of its atomic gain profile (conditions for Lamb dip). A theoretical solution of the problem is developed, and a detailed discussion of line shapes and physical processes involved is included.

Feldman, B. J.↗

NASA NTRS1970

Theory of a high-intensity gas laser

Single mode gas laser theory for arbitrary field intensities in terms of ensemble averaged form of density-matrix equations of motion

Feld, M. S.↗