An electron moir■ method for a common SEM

In the electron moiré method, a high-frequency grating is used to measure microscopic deformation, which promises significant potential applications for the method in the microscopic analysis of materials. However, a special beam scanning control device is required to produce a grating and generate a moiré fringe pattern for the scanning electron microscope （SEM）. Because only a few SEMs used in the material science studies are equipped with this device, the use of the electron moiré method is limited. In this study, an electron moiré method for a common SEM without the beam control device is presented. A grating based on a multi-scanning concept is fabricated in any observing mode. A real-time moiré pattern can also be generated in the SEM or an optical filtering system. Without the beam control device being a prerequisite, the electron moiré method can be more widely used. The experimental results from three different types of SEMs show that high quality gratings with uniform lines and less pitch error can be fabricated by this method, and moiré patterns can also be correctly generated.

Improved Data Compression Scheme for Multi-Scan Designs

This paper presents an improved test data compression scheme based on a combination of test data compatibility and dictionary for multi-scan designs to reduce test data volume and thus test cost. The proposed method includes two steps. First a drive bit matrix with less columns is generated by the compatibilities between the columns of the initial scan bit matrix, also the inverse compatibilities and the logic dependencies between the columns of mid bit matrixes. Secondly a dictionary bit matrix with limited rows is constructed, which has the properties that for each row of the drive bit matrix, a compatible row exists or can be generated by XOR operation of multiple rows in the dictionary bit matrix and the total number of rows used to compute all compatible rows is minimal. The rows in the dictionary matrix are encoded to further reduce the number of ATE channels and test data volume. Experimental results for the large ISCAS 89 benchmarks show that the proposed method significantly reduces test data volume for multi-scan designs.

Low bend loss,high index,composite morphology ultra-fast laser written waveguides for photonic integrated circuits

We demonstrate a novel,composite laser written 3D waveguide,fabricated in boro-aluminosilicate glass,with a refractive index contrast of 1.12×10^(−2).The waveguide is fabricated using a multi-pass approach which leverages the respective refractive index modification mechanisms of both the thermal and athermal inscription regimes.We present the study and optimisation of inscription parameters for maximising positive refractive index change and ultimately demonstrate a dramatic advancement on the state of the art of bend losses in laser-written waveguides.The 1.0 dB cm−1 bend loss cut-off radius is reduced from 10 mm to 4 mm,at a propagation wavelength of 1550 nm.