TY - GEN
T1 - Investigation of near and mid infra-red (1.34,1.55 & 8.1μm) laser propagation through the New York city metro area
AU - Corrigan, Paul
AU - Martini, Rainer
AU - Whittaker, Edward
AU - Gmachl, Claire
PY - 2007
Y1 - 2007
N2 - Low power Mid-IR laser light exhibits much lower attenuation in propagation through the New York metro area when compared to Near-IR wavelengths. Depending on the type of atmospheric extinction we record a reduction of up to 800% in the exponential Beer-Lambert coefficient for Mid-IR light compared to Near-IR, thereby demonstrating the possibility of significantly increased deployable range and SNR of current communication systems by utilizing the Mid-IR spectrum. We present and analyze transmission data from an outdoor collinear, coaxial, multi-wavelength laser test bed comparing 1.31μm, 1.5 5μm and 8μm through outdoor atmospheric fog and rain over a 550 m free space optical link across the Stevens Institute of Technology campus. This is achieved using lasers with average power ranging from 1 mW (Mid-IR QCL) to tens of milliwatts which have been normalized under lock-in detection. We also present corroborating results from an indoor fog experiment simulating various fog types. Here we have also deconstructed Beer's attenuation coefficient and distinguish the contribution of scattering and absorption with a purpose-built polar nephelometer. Using Mie predictions we determine and measure the extent by which a Mid-IR system scatters light less under fog than a traditional Near-IR one, hence accounting for the performance enhancement in the metro-air test bed. We conclude finally that the Kruse-Mie prediction of insignificant Mid-IR-over-Near-IR-gain is strongly in error.
AB - Low power Mid-IR laser light exhibits much lower attenuation in propagation through the New York metro area when compared to Near-IR wavelengths. Depending on the type of atmospheric extinction we record a reduction of up to 800% in the exponential Beer-Lambert coefficient for Mid-IR light compared to Near-IR, thereby demonstrating the possibility of significantly increased deployable range and SNR of current communication systems by utilizing the Mid-IR spectrum. We present and analyze transmission data from an outdoor collinear, coaxial, multi-wavelength laser test bed comparing 1.31μm, 1.5 5μm and 8μm through outdoor atmospheric fog and rain over a 550 m free space optical link across the Stevens Institute of Technology campus. This is achieved using lasers with average power ranging from 1 mW (Mid-IR QCL) to tens of milliwatts which have been normalized under lock-in detection. We also present corroborating results from an indoor fog experiment simulating various fog types. Here we have also deconstructed Beer's attenuation coefficient and distinguish the contribution of scattering and absorption with a purpose-built polar nephelometer. Using Mie predictions we determine and measure the extent by which a Mid-IR system scatters light less under fog than a traditional Near-IR one, hence accounting for the performance enhancement in the metro-air test bed. We conclude finally that the Kruse-Mie prediction of insignificant Mid-IR-over-Near-IR-gain is strongly in error.
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U2 - 10.1117/12.720015
DO - 10.1117/12.720015
M3 - Conference contribution
AN - SCOPUS:35948937648
SN - 0819466735
SN - 9780819466730
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Atmospheric Propagation IV
T2 - Atmospheric Propagation IV
Y2 - 11 April 2007 through 12 April 2007
ER -