The present invention relates to noninvasive diagnostic systems for cancer detection comprising RGB-imaging of cancer cells, buccal epithelium cells and uses of the system for drug discovery. The present invention provides novel algorithms for the detection of malignancy associated changes of buccal epithelial cells based on RGB analysis.

Organic and organic/inorganic hybrid bulk heterojunction photovoltaic devices with improved efficiencies are disclosed. The organic photovoltaic device comprises a photoactive polymer:fullerene C.sub.60-carbon nanotube (polymer:C.sub.60-CNT) composite as a component of the active layer. Under light irradiation, photoinduced charge separation at the polymer:C.sub.60 interface is followed by electron transfer from C.sub.60 onto CNTs for efficient electron transport towards an electrode. The organic/inorganic hybrid photovoltaic device comprises quantum dots and carbon nanotubes. Power conversion efficiency enhancement methods of polymer-CNT based photovoltaics are also provided.

Methods and apparatus are provided employing rapid scanning continuous wave terahertz spectroscopy and imaging for the non-destructive evaluation of materials such as animal hides and natural cork, and explosive detection, concealed weapon detection, and drug detection. A system employing an aperiodic detector array and implementing phase modulation at 100 kHz significantly reduces the imaging time and enables interferometric images of a THz point source to be obtained at several frequencies between 0.3 and 0.95 THz.

The theory, design, fabrication, and characterization of MEMS (micro electrical mechanical system) Fabry-Perot diaphragm-fiber optic microphone are described in the present invention. By using MEMS technology in processing and packaging, a square 1.9 mm.times.1.9 mm, 2 .mu. thick SiO.sub.2 diaphragm with a 350 .mu. square embossed center of silicon is mechanically clamped to the ferrule of a single mode fiber to keep its closeness (5 .mu.) and perpendicular orientation with respect to the diaphragm. Static measurement of optical output power versus the pressure on membrane reveals more than one period of Fabry-Perot interference, thereby generating a Fabry-Perot diaphragm-fiber interferometer device accurately reproducing audible acoustic wave.

An apparatus and method for steganalysis that enhances the ability to detect distortion introduced by data hiding. In embodiments of the invention, a pixel grayscale value in an image is predicted by using its neighboring grayscale values of neighboring pixels. Further, a prediction-error image is produced by subtracting the image from its predicted image. The prediction-error image may is employed to remove at least some variations in image data other than those associated with data hiding an thus, at least partially offsets variations from image aspects other than data hiding.