Modified PN code laser modulation technique for laser measurements
Modified PN code laser modulation technique for laser measurements
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DOI：
10.1117/12.817254
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发表时间：
2009-02
期刊：
影响因子：
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通讯作者：
Xiaoli Sun;J. Abshire
中科院分区：
文献类型：
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作者：
Xiaoli Sun;J. Abshire
Pseudo-noise (PN) modulation techniques have been used to modulate lasers for time of flight measurements and for profiling atmospheric backscatter. Compared to mono-pulse techniques, PN code modulation allows timing and backscatter measurements to be made with much lower laser peak powers and higher duty cycles. We have developed a new modified version of PN code modulation for laser measurements in which the laser pulse width and position may also be varied within the PN code bit interval. These allow more degrees of freedom for optimizing laser measurements. We have demonstrated these in laboratory measurements using a 974 nm laser diode, return to zero (RZ) PN code modulation at various laser pulse duty cycles, and a photon counting receiver. The results show significant improvements in the receiver signal to noise ratio, sensitivity, and ranging precision for the lower duty cycle RZ PN codes.
