All-optical Ti:PPLN wavelength conversion modules for free-space optical transmission links in the mid-infrared

摘要

Data-format-independent all-optical transmitter and receiver modules for free-space optical communica-ntions in the 3.8 u0001m region have been developed, essentially consisting of Ti-indiffused, periodically polednLiNbO3 waveguides. Using these modules, conversion of C-band radiation to/from the mid-infrared (MIR)nvia difference-frequency generation was demonstrated. More than 10 mW of MIR power could be generatednwith the transmitter unit; the internal low-power conversion efficiency was 69%/W. A free-space MIR linknwas set up with a −41 dB fiber-to-fiber loss; only −15 dB are due to the parametric processes.