Low-loss parallel-plate waveguide at 10.6 μm

Abstract

A slightly curved parallel-plate waveguide made of metal or dielectric material is proposed for a low-loss and self-focusing optical guide for CO2 laser beams. The minimum-loss TE1 mode in a copper guide with a separation of 0.5 mm has a transmission loss as low as 0.02 dB/m, and the loss is 6 times less than that of the TE01 mode in the hollow circular guide of diameter equal to the separation. Theoretical prediction of the low-loss and self-focusing characteristics of the waveguide has been experimentally confirmed.