Observation of undamped pulsations in a low-pressure, far-infrared laser and comparison with a simple theoretical model

Journal Article · Tue Jan 01 00:00:00 EST 1985 · J. Opt. Soc. Am. B: Opt. Phys.; (United States)

DOI:https://doi.org/10.1364/JOSAB.2.000023· OSTI ID:5893134

Abraham, N B; Dangoisse, D; Glorieux, P; Mandel, P

Experimental details of undamped pulsations are presented for a low pressure, far-infrared (FIR) laser optically pumped by a single-frequency CO/sub 2/ laser in a standing-wave configuration for both the pumping and the FIR lasing action. Spontaneous pulsing in the single-mode HCOOH FIR laser at 742 ..mu..m was observed when the cavity was tuned to the FIR resonance and when the CO/sub 2/ laser of high intensity was sufficiently detuned from the resonance of the pump transition to excite two distinct velocity groups of molecules to contribute to the FIR gain. Theoretical results, based on studies of a model for a laser with two distinct resonant species forming the gain medium, provide a basis for understanding the origin of these instabilities. The model compares satisfactorily with the observed FIR instabilities including the variations in pulsing frequencies observed experimentally as the CO/sub 2/ laser is detuned. Additional predictions from the model include details of transitions from cw to pulsing behavior and thresholds for deterministic chaos that may be tested in future experiments.

• Research Organization: Istituto Nazionale di Ottica, Largo Enrico Fermi 6, and Dipartimento di Fisica, Universita di Firenze, 50125 Firenze, Italy
• OSTI ID: 5893134
• Journal Information: J. Opt. Soc. Am. B: Opt. Phys.; (United States), Vol. 2:1
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
LASER CAVITIES
GAIN
INSTABILITY
NONLINEAR OPTICS
DAMPING
EXCITATION
FAR INFRARED RADIATION
LINE BROADENING
NONLINEAR PROBLEMS
OPTICAL MODES
OPTICAL PUMPING
OSCILLATIONS
PULSATIONS
RESONANCE
TUNING
AMPLIFICATION
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
INFRARED RADIATION
OPTICS
OSCILLATION MODES
PUMPING
RADIATIONS
420300* - Engineering- Lasers- (-1989)