Prism coupling of infrared electromagnetic surface waves by Gaussian light beams

A study was made of the losses in prism-coupled excitation of surface electromagnetic waves in the infrared range (λ = 10μ). It was found that the effects of diffraction of the light at the edges of the prisms play an important role in the excitation of such waves. The measured value of the coupling efficiency η = 8% was somewhat lower than the calculated value of 13%.