Mach-Zehnder Interferometer Method Research Articles

Demonstration of all-optical phase modulation in polydiacetylene waveguides

We present the first demonstration of all-optical phase modulation in the waveguides of an organic material {poly[bis-(p-toluene sulfonate) of 2, 4-hexadiyne-1, 6-diol]}. The phase change as a function of optical intensity has been measured via the Mach–Zehnder interferometric method. A π phase shift has been observed for a 2-mm-long waveguide as the peak intensity is increased by ∼7 MW/cm2 for polarization parallel to the chain axis (λ=1.06 μm). Through detailed polarization-selective measurements we have established that the observed phase change is electronic (nonthermal) in origin. The results are highly encouraging in terms of all-optical device applications of the material.

Measurements of the anisotropic nonlinear refractive-index coefficients of ruby

The real part n(2)' of the complex nonlinear refractive-index coefficients of ruby crystal (Cr(3+):Al(2)O(3)) are measured by the Mach-Zehnder interferometric method. The n(2)' values measured at 514.5 nm for the light polarization perpendicular (sigma) and parallel (pi) to the crystal c axis are (2.81 +/- 0.36) 10(-8) and (1.33 +/- 0.17) x 10(-8) cm(2)/W, respectively. From the results obtained the ratio of the polarizability difference between the excited and ground states of Cr(3+) in ruby for sigma polarization to that for pi polarization is found to be 1.05 +/- 0.30.