Random lasing in weakly scattering systems

Journal Article · Wed Nov 15 04:00:00 EST 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.74.053812· OSTI ID:20979345

Wu, X; Fang, W; Cao, H ^[1]; Yamilov, A ^[1]; Chabanov, A A ^[1]; Asatryan, A A; Botten, L C ^[2]

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1. Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States)
2. Centre for Ultrahigh-bandwidth Devices for Optical Systems and Department of Mathematical Sciences, University of Technology, Sydney, New South Wales 2007 (Australia)

We present detailed experimental and numerical studies of random lasing in weakly scattering systems. The interference of scattered light, which is weak in the passive systems, is greatly enhanced in the presence of high gain, providing coherent and resonant feedback for lasing. The lasing modes are confined in the vicinity of the pumped volume due to absorption of emitted light outside it. In the ballistic regime where the size of the gain volume is less than the scattering mean free path, lasing oscillation occurs along the direction in which the gain volume is most extended, producing directional laser output. The feedback for lasing originates mainly from backscattering of particles near the boundaries of the pumped region. It results in nearly constant frequency spacing of lasing modes, which scales inversely with the maximum dimension of the gain volume.

• OSTI ID: 20979345
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 74; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION
BACKSCATTERING
EMISSION
GAIN
INTERFERENCE
LASERS
LIGHT SCATTERING
MEAN FREE PATH
NUMERICAL ANALYSIS
OSCILLATIONS
RANDOMNESS