Mode-medium instability in an unstable resonator

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Appl. Opt.; (United States)

DOI:https://doi.org/10.1364/AO.27.000058· OSTI ID:5733715

Sung, C C; Li, Y Q; Smithers, M E

The mode-medium instability of an active medium in an unstable resonator is investigated. The asymptotic solution due to Horwitz, valid for large Fresnel numbers in an empty cavity, is modified by introducing gain/phase sheets in front of the resonator mirrors. The effect of medium coupling to the mode in the cavity is obtained by introducing a general time-independent Green's function in the Fox-Li formulation. The time evolution is then obtained by repeated integration of the beam propagation in the cavity. The diffractive terms are shown to grow rapidly at the expense of the geometric term. This instability responsible for the deterioration of the beam quality is studied numerically for a CO/sub 2/ lasing system as an example.

• Research Organization: University of Alabama in Huntsville, Physics Department, Huntsville, Alabama 35899
• OSTI ID: 5733715
• Journal Information: Appl. Opt.; (United States), Journal Name: Appl. Opt.; (United States) Vol. 27:1; ISSN APOPA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
DESIGN
ELECTRONIC EQUIPMENT
EQUIPMENT
INSTABILITY
LASER CAVITIES
OPTICAL MODES
OSCILLATION MODES
RESONATORS
TIME DEPENDENCE