Excess spontaneous emission in variable-reflectivity-mirror lasers

Journal Article · Tue Aug 01 04:00:00 EDT 1989 · IEEE J. Quant. Electron.; (United States)

DOI:https://doi.org/10.1109/3.34058· OSTI ID:5606543

Doumont, J L; Mussche, P L; Siegman, A E

The authors calculate the so-called excess spontaneous emission factors, or excess noise factors, for the lowest and higher order transmission modes in geometrically stable and unstable laser cavities having Gaussian variable-reflectivity mirrors. These excess emission factors determine both the Schawlow-Townes linewidths or quantum noise fluctuations in laser oscillators and the initial noise levels from which oscillation buildup starts in regenerative laser cavities. The excess emission factor for the lowest order Gaussian mode is found to be near unity for geometrically stable resonators, rise to a value very close to 2 at the stable-unstable boundary (planar-mirror case), and becomes substantially larger than unity for cavities having geometrically unstable optics. Excess emission factors as large as 10-100 times and larger are obtained in cavities having geometric magnifications of order 1.5-2 and aperture Fresnel numbers of a few times unity, increasing quadratically for higher values of the Fresnel number of the square of the magnification. Higher order modes have even larger excess noise factors.

• Research Organization: Stanford Univ., CA (USA). Edward L. Ginzton Lab.
• OSTI ID: 5606543
• Journal Information: IEEE J. Quant. Electron.; (United States), Journal Name: IEEE J. Quant. Electron.; (United States) Vol. 25:8; ISSN IEJQA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
BEAM OPTICS
CALCULATION METHODS
EMISSION
EQUIPMENT
FRESNEL REFLECTORS
GAUSSIAN PROCESSES
GEOMETRY
LASER CAVITIES
LASER MIRRORS
MATHEMATICS
MECHANICS
MIRRORS
NOISE
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
QUANTUM MECHANICS
REFLECTIVITY
SOLAR CONCENTRATORS
SOLAR EQUIPMENT
SOLAR REFLECTORS
SURFACE PROPERTIES