Fig. 4: Experimental setup of the heterodyne measuring system between the reference laser and the inhibited laser.
From: An inhibited laser

MTS modulation transfer spectroscopy, IF-ECDL interference filter configuration external cavity diode laser, PZT piezoelectric ceramic, M1 and M2 cavity mirrors, DM1 dichroic mirror coated with anti-reflection coating at 1470 nm and high-reflection coating at 459 nm; HWP halfwave plate, DM2 dichroic mirror coated with high-reflection at 1470 nm and anti-reflection at 459 nm; HM 1470 nm heterodyne module, PD photodetector, FA frequency analyzer.