CROSS-CHIRPED INTERFEROMETRY SYSTEM AND METHOD FOR LIGHT DETECTION AND RANGING

摘要

An interferometric method and system enabling light echoes-to-spectrum mapping, applicable for laser rangefinder, biomedical imaging including surface 3D mapping and tomography, vehicle position identification, and spectrum analysis. The direct mapping into spectrum allows a time-of-flight detection without using any timing pulse modulation, The sensitivity of the detection can be as high as that of the conventional low coherence interferometry, thereby an eye-safe and low-cost solution not compromising performance. In a practical implementation, high accurate range detection can be easily achievable with the level of accuracy equivalent to the laser rangefinder using a 20 ps Full-Width-at-Half-Maximum (FWHM) timing pulse. The system and method comprise applying dispersion-unbalanced interference (referred to as 'cross-chirp interference') and gating a phase matched spectral component. The dispersion unbalance used to induce linear one-to-one correspondence between the relative time delay and the spectral component, the performances in terms of range and resolution of the system and method increase with the increase in dispersion unbalance.