Measuring Optical Length and Analyzing Accuracy Error Based on All-Fiber Optic Interferometer

An optical length measuring system base on all-fiber optic interferometer is proposed. The theoretical analysis indicates that, when the two branches of the interferometer are equal, the output have the maximum coherent intensity. Therefore, the optical length can be obtained by measuring the distance of collimator movement. Through the experiment and simulation, the impact of the signal-to-noise ratio and fluctuation of the coupling efficiency on null error has been obtained.

On variation of surface topography and robust product performance

The customer's demands for higher quality,faster delivery times and reduction of cost,give evidence for the need to develop new technologies or enhance existing technologies combined with research activities.The automotive industry's capability to develop new products in a shorter time is constantly improved.Tool and die creation is a major part of the product creation for many industrial products and in particular for the automotive industry.The higher product requirements on reduced weight,better safety,and lower emissions have meant that a larger number of automotive body parts must be made in advanced high strength steels.Improved functionality of surface textures and engineered tailor made component surfaces is one enabling technology for industry to increase compete ability by improved component function and reduced friction losses.However,material properties'variation,un-evenly spread wear,unknown manufacturing process variations,the“human factor”,faulty metrology procedures…All factors interact to increase the problems of utilizing surface texturing on the micro metre level as a competitive tool for industry.Large variation of the micro topography created by industrial machining processes tends to reduce the impact of the usage of improved engineered surfaces on critical components.A proposal of a strategy for metrology using"intelligent"sampling techniques comprising of regionalization of the functional area and designed sampling patterns is presented.To efficiently make use of efficient sampling,an example of a recently developed optical scattering light in-line metrology of high precision surfaces is discussed as a tool to enable efficient control of machine tools in general.Future steps discussed include developing of control loops for implementation in CNC controllers to efficiently make use of the"smart"surface texture characterisation data from the developed in-line surface texture sensors.

A dynamic optical arbitrary waveform generator based on cross phase modulation

In this paper, a dynamic optical arbitrary waveform generator(OAWG) based on cross phase modulation(XPM) is proposed. According to the characteristics of XPM, the nonlinear phase shift of signal can be changed along with the pump power. The amplitude of signal can be changed by controlling the phase shift at one arm of a Mach-Zehnder interferometer(MZI) using XPM effect between signal and pump. Therefore, the phase and amplitude of the optical frequency comb(OFC) can be controlled by two pump arrays. As a result, different kinds of waveforms can be synthesized. Due to the ultrafast response of XPM, the generated waveform could be dynamically updated with an ultrafast frequency. The waveform fidelity is affected by the updating frequency.