Fig. 1From: Passive coherent dual-comb spectroscopy based on optical-optical modulation with free running lasersBlock diagram of the OFMCs. DM, dichroic mirror; BS, beam splitter; M, mirror; L, lens; PPLN, periodically poled LiNbO3; HWP, half wave plate; PBS, polarizing beam splitter; BPD, balanced photodetectorBack to article page