Journal article
Reduction of phase-induced intensity noise in a fiber-based coherent Doppler lidar using polarization control
Optimization of signal-to-noise ratio is an important aspect in the design of optical heterodyne detection systems such as a coherent Doppler lidar (CDL). In a CDL, optimal performance is achieved when the noise in the detector signal is dominated by local oscillator shot-noise. Most modern CDL systems are built using rugged and cost-efficient fiber optic components.
Unfortunately, leakage signals such as residual reflections inherent within fiber components (e.g. circulator) can introduce phaseinduced intensity noise (PIIN) to the Doppler spectrum in a CDL. Such excess noise may be a few orders of magnitude above the shot-noise level within the relevant CDL frequency bandwidth – corrupting the measurement of typically weak backscattered signals.
In this study, observation of PIIN in a fiber-based CDL with a master-oscillator poweramplifier tapered semiconductor laser source is reported. Furthermore, we experimentally demonstrate what we believe is a newly proposed method using a simple polarization scheme to reduce PIIN by more than an order of magnitude.
Language: | English |
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Year: | 2010 |
Pages: | 5320-5327 |
ISSN: | 10944087 |
Types: | Journal article |
DOI: | 10.1364/OE.18.005320 |
ORCIDs: | Rodrigo, Peter John and Pedersen, Christian |