Abstract:A low-voltage-tunable one-dimensional nanobeam laser is realized by employing lithographically defined lateral electrodes. An InGaAsP nanobeam with a sub-micrometer width is transfer-printed in the middle of two electrodes using a polydimethylsiloxane stamp. Spectral tuning is achieved by controlling the molecular alignment of the surrounding liquid crystals (LCs). From μm-scale-gap structures, a total wavelength shift that exceed 6 nm is observed at a low voltage of less than 10 V. A measured spectral tuning rate of 0.87 nm/V, which is the largest value ever reported to our knowledge among LC-tuned photonic crystal lasers, was also noted. Lehman, "Tunable two-dimensional photonic crystals using liquid-crystal infiltration," Phys. Rev. B 61(4), R2389-R2392 (2000). 17. Ch. Schuller, F. Klopf, J. P. Reithmaier, M. Kamp, and A. Forchel, "Tunable photonic crystals fabricated in III-V semiconductor slab waveguides using infiltrated liquid crystals," Appl. Phys. Lett. 82(17), 2767-2769 (2003). 18. A. Casas Bedoya, S. Mahmoodian, C. Monat, S. Tomljenovic-Hanic, C. Grillet, P. Domachuk, E. C. Mägi, B. J.Eggleton, and R. W. van der Heijden, "Liquid crystal dynamics in a photonic crystal cavity created by selective microfluidic infiltration," Opt. Express 18(26), 27280-27290 (2010

The virtual target signal generator was developed to verify the shipborne tracking radar performance. It was used to DRFM(Digital RF Memory) method to generate the virtual moving targets. The target signal includes Doppler shift and RCS according to the target motion. And the signal generator can make jamming signal and clutter to test shipborne radar performance at real environmental condition. This paper described the functional diagram and the hardware configuration items to meet the test requirements for the tracking radar. And it showed the critical design points for the sub-systems. The signal generator which was developed in this paper shared the operational information of the radar with the radar command and control part. To test the frequency agility of the radar, it had the local oscillator which could do high speed frequency switching according to radar information. By communicating between the signal generator and the radar command and control part, the local oscillator of signal generator could be controlled every pulse. It reduced the instantaneous bandwidth of signal generator and minimized the spurious. So it lowered the probability of generating wrong targets.

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