Dug Y. Kim

Third order nonlinearity of 4‐dialkylamino‐4’nitro‐stilbene waveguides at 1319 nm

The intensity dependent optical properties of 4‐dialkylamino‐4’nitro‐stilbene polymer channel waveguides were measured at 1319 nm with a pulse modulated Mach–Zehnder interferometer to be n2=0.8×10−13 cm2/W and β2<0.08 cm/GW. This material is promising for all‐optical switching at 1319 nm because it satisfies both the W and T figures of merit.

Assessment of single crystal p‐toluene sulfonate as an all‐optical switching material at 1.3 μm

We evaluate the potential of single crystal PTS (p‐toluene sulfonate) for all‐optical applications at the 1.32 μm communications wavelength by measuring the electronic and thermo‐optic nonlinearities, and the multiphoton absorption with picosecond pulses. With appropriate heat sinking, duty cycles greater than 25% should be possible without significant cumulative thermal effects for 1 W operating powers.

Cascading nonlinearities in an organic single crystal core fiber: The Cerenkov regime

The large nonlinear phase shifts imparted to the fundamental beam during Cerenkov second harmonic generation (SHG) in a DAN, 4-(N,N-dimethylamino)-3-acetamidonitrobenzene, single crystal core fiber are explained and modelled numerically. Cascading upconversion and downconversion processes leads to nonlinear phase shifts produced by the second order nonlinear coupling of the guided fundamental mode and the component of the Cerenkov second harmonic field trapped in the fiber cladding.

Cascading: Modelling a New Route to Large Optical Nonlinearities and All-Optical Devices

One of the attractive possibilities offered by nonlinear optics is the application of an intensity dependent refractive index to various all-optical switching, data processing and logic operations. Despite the concentrated effort made in searching for materials with large nonlinearities and low linear and nonlinear losses, the powers required for integrated optical waveguide device operation are still of the order of watts.

Pulse-Shape Dependent Time Averaging Effects in Interferometric Nonlinear Phase Shift Measurements

When optical pulses of temporal width less than or comparable to a detectors response time are used to interferometrically measure intensity-dependent phase shifts, it becomes necessary to use time-averaging protocols to deduce the material nonlinearity. Relations between the actual peak nonlinear phase shifts and the measured values are numerically evaluated for Gaussian and sech square pulse shapes. We believe that these results are also very important to understand the pulse break-up effect in Mach-Zehnder type all-optical switching applications.

Cascading of second-order processes in quadratic molecular media at the origin of very large cubic effects

Abstract We have shown that very large nonlinear shifts ranging from π/4 to π/2 observed at relatively modest input intensities in single-crystal cored fibers of 4-( N , N -dimethylamino)-3-acetamidonitrobenzene (DAN) have their origin in the cascading of two second-order nonlinear processes: second-harmonic generation followed by down-frequency conversion. The nonlinear shifts and corresponding n 2 values extracted from independent observationsof self-phase modulation and direct interferometric measurements are as large as 10 −12 cm 2 /W at relatively modest input intensities from 30 to 60 MW/cm 2 . The cascading origin of large n 2 values was fully confirmed by z -scan measurements performed on a single DAN crystal.

Second-order cascaded nonlinearity in lithium niobate channel waveguides

Here we describe a systematic interferometric investigation of the influence of the wavevector-mismatch on cascading. Titanium indiffused LiNbO/sub 3/ waveguides are used because their superior optical quality and the detailed knowledge of their fabrication and characterization make them promising candidates for the first application of cascading in all-optical data processing.<<ETX>>