Live Electrooptic Imaging of $W$-Band Waves

A novel method for real-time visual observation of traveling -band waves is described. Wave images and movies are acquired by a live electrooptic imaging (LEI) camera equipped with an optical source that emits signals modulated at a local oscillator (LO) frequency in the -band range. Waves propagating in a slab waveguide made of a semiconductor plate as well as in the air are successfully visualized. Especially in this paper, -band wave images for the aerial propagation in a variety of forms are presented: spherical and plane waves together with some fundamental wave phenomena such as reflection, interference, and diffraction at metal-air interfaces. The principle of 100-GHz optical LO signal generation at the optical wavelength of 780 nm as well as performance parameters such as the spatial resolution, bandwidth, and dynamic range of the camera are discussed. Further, some preliminary applications of the scheme are presented.