Field tests for round-trip imaging at a 14  km distance with change detection and ranging using a short-wave infrared super-continuum laser

Abstract

Field tests have been conducted of a broadband illuminator for active hyperspectral imaging (HSI) using a short-wave infrared supercontinuum laser (SWIR-SCL). We demonstrated irradiance comparable to the sun for two-way measurements at a 1.4 km distance between laser and target, and performed change detection and ranging. The experimental results suggest that the range resolution of our method is ∼1.5 cm even at the 1.4 km distance. Hence, we demonstrated the possibility to perform HSI with active broadband illumination using the SWIR-SCL. To our knowledge, this experiment is the first-ever to test two-way propagation of the active HSI illumination over a long distance. The 64 W SWIR-SCL provides near sunlight-equivalent illumination over multiple square meters, and the laser could enable HSI 24 h a day, even under a cloud cover, as well as enhanced capabilities such as change detection and ranging.

Watt-level and spectrally flat mid-infrared supercontinuum in fluoroindate fibers

“…High brightness broadband sources in mid-infrared (MIR) atmospheric transmission windows have attracted a significant scientific interest in the past decade due to their wide range of potential uses in various fields, such as spectroscopy, metrology, as well as defense applications [1][2][3]. Supercontinuum (SC) sources using fluorozirconate-based fibers have reached watt level powers [4][5][6][7][8][9], some of which extended up to 4.7 μm by using short ZBLAN fibers [10], but usually the SC extensions are restricted to wavelengths below ∼4.2 μm when using long ZBLAN fibers.…”

Active spectrum tailoring of in-amplifier mid-infrared supercontinuum generation

“…Researches on high-power mid-infrared (MIR) supercontinuum (SC) lasers using non-silica fibers like ZBLAN fiber has gained attention for their potential applications in environmental sensing [1], infrared spectroscopy [2] and homeland security [3]. Compared with passive ZBLAN fibers, rare-earth-doped fibers (i.e., active fibers), such as Er-doped ZBLAN fiber, have been introduced to enhance power amplification and broaden the spectrum beyond 3 μm [4].…”

Active Hyperspectral Sensor Based on MEMS Fabry-Pérot Interferometer

“…SC is generated via spectral broadening of a short high-power monochromatic laser pulse in an optically non-linear material, usually an optical fiber [6]. The resulting light can have an optical bandwidth spanning over multiple octaves [7] but can still be directed and focused over long distances [8,9,10,11] as a regular laser. The potential applications for the technology include mineral survey, the automotive industry and agriculture.…”