In this paper, we upconvert images provided by 1.5 μm collimated continuous wave lasers illuminating resolution targets and small objects. Using a 2.7 nm wide pump spectrum at 1064 nm, we resolve 56x64 spatial elements whereas we obtained only 16x19 spatial elements with a narrow spectrum pump laser at 1064 nm with the same beam diameter and 8x8 spatial elements with a 0.5 mm thick crystal. These results are compatible with long range target recognition. A laboratory scale experiment of active imaging of diffusive objects is shown as an illustration. |
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Crystals
Upconversion
Image resolution
Phase matching
Signal detection
Imaging systems
Nonlinear crystals