Abstract:The impacts of interband and intraband crosstalk are studied and compared experimentally. Results show that interband crosstalk can be removed with narrow-band filters and has no influence on signal. Intraband crosstalk will result in signal eye diagram close and BER increasing. When the polarization states of signal and crosstalk align, intraband crosstalk seriously decreases signal quality. But when they misalign, it has little influence. Coherent and incoherent crosstalk are studied experimentally. Results show that coherent crosstalk is less harmful to system performance than incoherent crosstalk.

Abstract:Today,micro-system technology and the development of new MEMS(Micro-Eleetro-Mechanical Systems)ate emerging rapidly.In order for this development to become a SUCCESS in the long run,measurement systems have to ensure product quality.Most often,MEMS have to be tested by means of functionality or destructive tests.One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities.We present a measurement system that could be used for these kinds of measurements.The system combines a fiber optical,miniaturized sensing probe with low-coherence intcrferometry,so that absolute distance measurements with nanometcr accuracy are possible.

Abstract:A novel technology to manufacture holographic ion beam etched diffraction gratings based on surface thermokinematics is presented.The surface roughness of photoresist gratings is solved by this technology.According to this technology,a holographic ion beam etched blazed grating of 1200 1/mm for use in the ultraviolet region is manufactured.The experimental results show that the grating has good surface quality,low stray light and high diffraction efficiency.In addition,the performance of thes gratings satisfies the operating requirements of ultraviolet spectrograph.