Fig. 5: The schematic diagram of experimental setup for the radio ranging with NV center.
From: Quantum enhanced radio detection and ranging with solid spins

DM, long-pass dichroic mirror with an edge wavelength of 552 nm; AOM acousto-optic modulator, SPCM single-photon-counting modulator, PBS polarizing beam splitter, LP longpass filter with an edge wavelength of 633 nm; HWP half-wave plate.