Ultra-high vacuum optical second harmonic microscope

We have developed an optical second harmonic (SH) microscope for surface an alysis in ultra-high vacuum. We have combined a commercial long-distance mi croscope, intensified charge coupled device (CCD) camera, optical filters, a cavity dumped mode-locked Nd3+:YAG laser, and an ultra-high vacuum chambe r for constructing the SH microscope. The spatial resolution of the SH micr oscope is estimated to be around 6 mu m. We have observed a nonuniform dens ity distribution of CO adsorption on a Pt(110) surface.