on the sample parallelism on the order of a single fringe is routinely achieved this fabrication technique enables the production of a total internal reflection tir probe geometry which does not require the high reflection coating the electrode geometry is a coplanar strip transmission line with 5 u03bcm lines and spacings the tir geometry consisted of a simple multi line system with no contact pads within the time window probe 15 was used on samples on lt gaas substrates producing electrical pulses sup u02dc 1 ps fwhm sampling beam 17 is directed so that it impinges upon a facet of the pyramid is directed to a point in crystal probe 15 and is reflected toward the microscope objective 21 in this instance excitation beam 32 39 is directed as is shown in dashed lines in fig6 and impinges at about the same point as the sampling beam fig2 shows the measured response a linear lit to tile rise time 10 90 percent in fig2 is sup u02dc 400 fs in fig3 is shown a variant of supported probe 14 in this instance 9 free surface 7 of crystal probe 15 supported on rod 16 is coated with an hr coating 18 however the sides of the support rod and the crystal probe do not need to be shaped surface 7 becomes free after crystal probe 15 is secured on rod 16 and the gaas layer 5 is removed fig1 in this instance excitation beam 32 39 does not.