Figure 2
From: Pulsed Sagnac source of polarization-entangled photon pairs in telecommunication band
Experimental setup for generation of polarization-entangled photons in polarization-based Sagnac interferometer. Non-collinear photon pairs were generated in a type-0 PPLN crystal. Pump, mode-locked picosecond pulse laser (775 nm, 20 MHz, 3.5 ps); FC, SMF coupler for pump (p) and correlated photons 1 and 2; P, linear polarizer; H, half-wave plate; Q, quarter-wave plate; L, spherical lens (200-mm focal length); DPBS, dual-wavelength polarizing beam splitter; DHWP, dual-wavelength half-wave plate; M, mirror; PPLN, type-0 periodically-poled lithium niobate crystal with 10-mm length.
