In the paper, we propose a new method for chromatic dispersion measurement of WDM components in both transmission and reflection, employing photonic microwave technology. The dispersion can be determined by measuring the frequency spectrum range change of the microwave notch filter. The method features the advantages of low-cost and simplicity. Experimental results demonstrate that our setup is capable of measuring relative group delay with better than 1 ps time resolution and the measurement results show a good agreement with that measured by the conventional phase-shift technique.

Very reliable mode-locked semiconductor lasers have been developed. These devices provide high signal-to-noise ratio optical clock pulses of a few picoseconds temporal width in the 1.5-micrometer wavelength region. Potential applications of these lasers for high-bit-rate optical communication systems operating at over 40 Gbps including all-optical signal processing, and for very high-speed measurement systems are described.

A technique was developed to reconstruct the cross-sectional image of the absorption distribution in a diffuse medium using backscattered light. In this technique, we illuminate an object with an ultra-short pulse, and measure the time-resolved pulse shape of the light backscattered from the object. The absorption distribution of the scattering object can be estimated using the propagation-path distribution of photons at each detection time and the optical impulse response of backscattered light. In a simulation, the effectiveness of this technique was verified in the cases of a layered absorber and a three dimensional absorber. The nonlinear relationship between the depth of the probing region and the propagation time was clarified. The accuracy of the image reconstruction was significantly improved by the aperiodic sampling of the backscattered impulse response according to the nonlinear relation. The feasibility of the proposed technique was verified in the experiment with a model phantom.