Photonic-assisted endoscopic analysis of guided W-band pulses

We present a photonic-assisted time-domain measurement technique for exploring millimeter-wave propagation through a W-band waveguide. The electric fields, guided inside a rectangular waveguide, are sampled using a sub-millimeter-scale electro-optic probe. The probe is all-dielectric and sufficiently minute to enter into the waveguide through a probe-scale hole, thus minimally perturbing the original propagation of the fields. This photonic and endoscopic probing system provides access to time-domain internal fields, which is not been possible with a conventional oscilloscope.