Coherent Interference Between Two Linearly Polarized TEMoo cw-Lasers in a V-system on Dielectric Surfaces

Experimental results of energy retention from a TEMoo cw-laser beam on the vibratory dipoles of a glass surface through coupling between a weak probe laser with a stronger laser in a V-configuration is reported. Two diode lasers of 532 nm illuminate simultaneously the same crown glass in transparency regime. The opacity wavelength for our glass is 100 nm. The interaction is assisted by a capacitor voltage set up across the dielectric for a fine adjustment of the vibrational frequencies of surface dipoles illuminated by a probe laser. This configuration allows us to observe coherent interference between two cw-lasers of close frequencies but of different intensities, like in an EIT system. The parallel component of the reflectance near Brewster angle shows a peak, thus indicating that coupling laser takes over the probe in its interaction with the surface dipoles. Because the two laser beams have a long temporal coherence, several maxima and minima located 0.6 degrees apart in a region of 8 degrees wide near the Brewster angle are observed and interpreted as an interference pattern. Besides the retention of laser's energy on surfaces, this technique allows to create an optoelectronic switch for stopping and releasing a probe laser beam when the coupling laser is turned ON and OFF.