Nonlinear Optical Up-Converter for Eye-Safe Imaging

Active imaging in the short- and mid-wave infrared has well-known benefits versus shorter wavelengths: eye safety, better visibility through battlefield obscurants, high atmospheric transmission, and reduced background emission. However, there are no suitable imaging detectors at eye-safe wavelengths. In Phase I, CTI proposed a nonlinear sum-frequency generator (SFG) to convert an image at 1.55 mm to a shorter wavelength where better detectors exist. The SFG will provide spectral filtering and optical range-gating capability. In Phase I, CTI successfully performed risk reduction experiments that up-converted a multi-pixel image form the 1.5 mm region to 0.63 mm. This experiment provided proof of principle evidence for the multipixel imager that will be built in Phase II. In addition, detailed ladar and transceiver models were produced to ensure the feasibility of the NLO converter. In Phase II, CTI will expand on Phase I success to build a NLO imaging transceiver capable of range resolution that will convert eye-safe 1.5 mm returns to 0.63 mm where intensified cameras are available. CTI will leverage its extensive repertoire of nonlinear optics, remote sensing experience, and expertise in flight hardware to reduce risk and increase the probability of success.