Ultra-Miniature Lidar Scanner for Launch Range Data Collection

The most critical component in lidar is its laser scanner, which delivers pulsed or CW laser to target with desirable field of view (FOV). Most existing lidars use a rotating or oscillating mirror for scanning, resulting in several drawbacks. A lidar scanning technology was developed that could achieve very high scanning speed, with an ultra-miniature size and much lighter weight. This technology promises at least a 10× performance improvement in these areas over existing lidar scanners. Features of the proposed ultra-miniature lidar scanner include the ability to make the entire scanner <2 mm in diameter; very high scanning speed (e.g. 5–20 kHz, in contrast to several hundred Hz in existing scanners); structure design to meet stringent requirements on size, weight, power, and compactness for various applications; and the scanning speed and FOV can be altered for obtaining high image resolutions of targeted areas and for diversified uses. the output waveguides accommodates one mode only. At the input, the waveguide structure is symmetric and, therefore, the fundamental mode of the structure at the input is symmetric and the other mode is anti-symmetric. At the output, one of the waveguides is wider than the other, and therefore has a higher effective refractive index. For the light originating from the star, if the interferometer is perfectly balanced, the input field in the focal plane of the focusing optic at the input of the device is symmetric, while for the light field originating from the planet (assuming the exact π phase shift) it is anti-symmetric. Thus, in the two-mode input waveguide the starlight excites the fundamental mode, while the planet light excites the second, anti-symmetric, mode. This work was done by Alexander Ksendzov of Caltech for NASA’s Jet Propulsion Laboratory. Further information is contained in a TSP (see page 1). NPO-47834