Innovation and Development

First Prototype of New InSAR Developed

The first prototype of three-baseline cross-track InSAR of the Millimeter wave (MMW) developed by Prof. Li Daojing and his team from the Institute of Electronics, which is part of the project of new remote sensing technology of the earth observation and navigation. The new type InSAR prototype was verified by a flight-test, solving a series of key technical issues including overall design of MMW InSAR system, the high-precision motion compensation and imaging system, and the MMW InSAR data processing, etc. The prototype mounted on an agyro-stablilized camera platform uses only one receiver to complete the switching of the three channels’ broadband signal. The motion compensation was implemented based on China's independently developed mini-type position and orientation system, and a high-precision InSAR digital elevation map was generated. This project has improved the InSAR technology by expending it to the MMW band, which brings about a good application prospect in the field of airborne remote sensing, survey and mapping, and vegetation thickness measurement in particular.

CdTe Solar Cells Upgrade PV Quality

The Solar Cell Technology Department of the Institute of Electrical Engineering, CAS has successfully fabricated CdTe (cadmium telluride) polycrystalline thin films with the thickness of only 2 μm on commercial energy saving glass by magnetron sputtering deposition. The vacuum equipment and semiconductor materials used are all from domestic suppliers. The conversion efficiency for their CdTe solar cell achieves 12.78%, as certificated by the CAS PV and Wind Farm Test Center. Such properties require CdTe solar cell with only 1/100 thickness of silicon solar cell, which greatly reduces the material cost.

Years Efforts See a Great Leap Forward

The researchers of Institute of Semiconductors, CAS started the study on optical matrix processor based on free space optics at the end of 2007. Stimulated by the principles of optical matrix operation and integrated optics, they proposed the first silicon-based optical matrix processor and applied the Chinese patents (No: ZL.200810116741.0). It takes four years of hard work from the generation of the original idea to the breakthrough of the key technologies. They successfully fabricated carrier-injection silicon-based optical matrix operator with the calculation speed of 8×107 MAC/s (MAC: multiplication and accumulation) in October 2011. Theoretical analysis indicates that, with the improvement of clock frequency and integration density, future silicon-based optical matrix processor will have a calculation speed of 1015~16 MAC/s, which is about 5 orders of magnitude faster than that of Tiger SHARC processor of ADI Corporation (1.92×1010MAC/s). The above work has recently been published in Optics Express (20 2012）13560-13566). Prof. J. W. Goodman, pioneer of optical computing, comments that the use of wavelength multiplexing together with the wavelength specific matrix elements really simplifies the system, and being able to place it all on a chip is a great leap forward.