ABSTRACT
We demonstrate 160 Gbit/s return-to-zero (RZ) differential quarternary phase-shift keying (DQPSK) signal transmission over a 110 km single-mode fiber by taking advantage of mid-span optical phase conjugation (OPC). The technique is based on nonlinear wavelength conversion by cascaded second harmonic and difference frequency generation in a Ti:PPLN waveguide. Error-free operation with a negligible optical signal-to-noise ratio penalty for the signal after the OPC transmission without and with polarization scrambling was achieved. The results also show the polarization insensitivity of the OPC system using a polarization diversity scheme.
ABSTRACT
The efficiency of wavelength conversion by cascaded second harmonic generation / difference frequency generation (cSHG/DFG) in Ti:PPLN waveguides can be considerably improved by using a double-pass configuration. However, due to the wavelength dependent phase change by the dielectric folding mirror phase compensation is required to maintain an optimum power transfer. We experimentally investigated three different approaches and improved the wavelength conversion efficiency up to 9 dB in comparison with the single-pass configuration.
Subject(s)
Niobium , Optics and Photonics/instrumentation , Optics and Photonics/methods , Oxides , Equipment Design , Light , Models, Theoretical , Nonlinear DynamicsABSTRACT
A thermally fixed photorefractive Bragg grating is written in a single-mode Ti:Fe:Er:LiNbO3 channel waveguide and used to develop a distributed feedback-distributed Bragg reflector coupled cavity laser with a second broadband dielectric cavity mirror. The optically pumped (lambda(p) = 1480 nm, P = 130 mW) laser emits in single-frequency operation as much as 8 mW at lambda = 1557.2 nm with a slope efficiency of approximately 22%. The laser wavelength can be thermo-optically and electro-optically tuned over 100 pm.
ABSTRACT
All-optical wavelength selective single and dual channel dropping by sum frequency generation has been demonstrated in a periodically poled Ti:LiNbO(3) waveguide, which has two second harmonic phase-matching peaks. Less than -17 dB of channel dropping extinction ratio was observed with coupled pump power of 325 mW.
