Description: PI at ArkLight proposes a novel scheme for making cloud discrimination in the wavelength ranges of near-IR (1-1.8 µm) and mid-IR (3-4 µm). This scheme is based on optical phase conjugation from a second-order nonlinear medium. It overcomes the disadvantages of slow speed in photorefractive media and poor reflectivities in third-order nonlinear materials. During Phase 1, she will design novel phase-conjugate mirrors operating at the signal wavelengths of 1.27 µm and 1.57 µm. Subsequently, she will fabricate the designed phase-conjugate devices. The next step will be testing of the fabricated devices by investigating sum-frequency and difference-frequency generation in the transverse geometry. She will also carry out modeling efforts on the device performances for making cloud discrimination. This Phase 1 project will be carried out in collaboration with Prof. Ding at Lehigh University who is one of the pioneers in optical phase conjugation. The anticipated results for Phase 2 include implementation and testing of the phase-conjugate mirrors operating at 1.27 µm and 1.57 µm for correcting phase distortion and making cloud discrimination, optimization of the phase-conjugate mirrors, finding solutions to practical issues for deploying these mirrors in the ASCENDS mission, expansion of input wavelengths, incorporation with frequency up-conversion devices, and reports.

Benefits: A phase-conjugate mirror can be used in Missile countermeasure with significantly improved sensitivity and reliability. It can be also used to produce high-quality images through a turbulent medium for realizing applications in remote sensing. The new LIDAR system to be developed by PI by combining the phase-conjugate mirror with a sensitive detector and a laser has important applications in archaeology, meteorology and atmospheric environment, wind power, geology, physics and astronomy, biology and conservation, military and law enforcement, vehicles, imaging, and 3-D mapping.

The phase-conjugate mirrors fully implemented by PI during Phase 2 will meet the requirement of NASA as being defined by the NASA SBIR solicitation of TOPIC: S1 Sensors, Detectors, and Instruments. Specifically, these mirrors will be used to discriminate against the effects caused by cloud in the wavelength ranges of near-IR (1-1.8 microns) and mid-IR (3-4 microns). 3-D imaging systems by combining the mirror, a sensitive detector, and a laser can be used to realize coherent imaging LIDAR for the ASCENDS, DESDynI, LISA, Doppler Wind Lidar, and LIST mission programs after removing the influence caused by cloud. The energy sources of nine infrared luminous galaxies can be diagnosed by a ground-based 3-4 µm spectrometer to be developed by PI with a capability of correcting the effects caused by cloud.