Single mode operation of a Fabry–Perot laser locked by a tunable laser

Abstract

out-of-phase currents cancel off each other so that effective radiating aperture is reduced when compared with the conventional patch antenna with the same dimensions. Compared to a conventional antenna with a narrower length, the proposed antenna has higher gain and wider beamwidth in H-planes as shown in Figure 3(a). Figure 6 shows the normalized measured radiation patterns for the patch antenna with a length of L ϭ 45 mm. The computed H-plane E radiation patterns from the aperture model are also included for comparison. There is a 10.3% increase in the measured beamwidth, slightly (4% or 3°) smaller than that from the simulation shown in Figure 4(b) due to the material and manufacturing tolerance. The aperture model computation agrees well with the measured results. The increase in the beamwidth of the proposed antenna was observed. CONCLUSIONA beamwidth broadening technique for the microstrip patch antenna has been presented and experimentally validated. The study has shown that with two additional out-of-phase radiators, the beamwidth of the patch antenna has been widened. More importantly, with the same achieved gain, the proposed antenna has achieved a wider beamwidth. This technique can also be applied to patch antenna array system, where both gain and broad beamwidth specifications of the antenna are important. The computation efficient aperture model formulation for this antenna structure has been verified with the full wave simulator as well as the results from measurement.ABSTRACT: In this article, the single mode operation of a Fabry-Perot laser (FP-LD) subject to the optical injection from a tunable laser is investigated. The maximum side mode suppression ratio (SMSR) is 53 dB, and the locked wavelength range is about 46 nm, which can cover 58 International Telecommunication Union (ITU) wavelengths with 100 GHz spacing or 115 ITU wavelengths with 50 GHz spacing for wavelength division multiplexing (WDM) system. In the wavelength range from 1535 to 1569 nm, the SMSR is over 46 dB, and the frequency response of the injection-locked FP-LD can be improved with the proper wavelength detuning.