Near infrared micro pulse lidar of profiling atomospheric CO2

1.6um-wave length, fiber-based micro pulse lidar of profiling atmospheric CO2 was designed, The performance of this lidar was simulated. The transmitter of micro pulse lidar is based on semiconductor laser plus erbium-doped fiber amplifier with a saturated output power of 37dBm. The receiver employs photon counter and near infrared photomultiplier tube with quantum efficiency of 1%. A polarization-independent fiber-optic circulator is used as the transmit -receive switch. The system utilizes fiber devices for almost all components, e. g. wavelength-division -multiplexers/demultiplexers, isolator, filter, coupler, which make the system robust. Characteristic of this lidar is micro pulse energy 20uJ, high repetition rate of 20kHz and miniaturization. Signal simulations indicate that signal-to-noise ratio below 4. 7km is more than 10:1 ( 18 X 106 pulse). Anode dark count of 2 x 10(5)/s limits the system performance. New InGaAs/Si APD with separate absorption and multiplication region will improve the lidar performance.