Overnight, Beam expanded a bit more, adding another inch in length and eight inches in diameter.
The reported beam expanding units has the deficiencies of serious speckle effect of coherence and the strict tolerance of alignment, respectively.
The structures of such beam expanding units were determined by calculating linear system of equations, and two kind of them were selected by analyzing the feasibilities of different structures due to the solves of equations.
According to the results of simulations, the designed four components beam expanding unit is proven to be an optimal scheme because of the evident declines of the tolerance sensitivities and speckle effects.
By employing a pair of conical lenses and a cylindrical lens behind the beam expander, the expanded Gaussian laser was shaped to a line-shaped beam whose intensity distribution is more consistent with the required distribution.
As shown in Fig. 1, laser light emitted from a He-Ne laser (λ = 632.8 nm) after being expanded by beam expander BE is split into object wave and reference wave by beam splitter BS1.
The thermal actuator beams expand due to Joule heating upon application of a DC voltage, which loads both the specimen and the force sensing beam.
After the layer rose to about 400 km altitude (Fig. 2g i), the irregularities in a zonal dimension of about 150 km, mostly in the western beams, expanded abruptly up to high altitude, 500 km or greater.
The 785 nm beam was first expanded using a beam expander (BE2) so as to overfill the back aperture of the microscope objective and then reflected into the microscope by the 785 nm dichroic mirror (DM1).
