Generation of a narrow microwave carrier from a bimodal fiber laser

Abstract

band-pass filter are obtained as shown in Figure 5(a). Obviously, the band-pass filter behaves well in the pass-band of which the return loss is below À10 dB (from 4.66 to 5.55 GHz). The outband suppression is almost better than 20 dB. The simulated resonant characteristics of the three-cascaded CSRR band-pass filter are obtained as shown in Figure 5(b). As can be seen from Figure 5(b), the return loss of the three-cascaded CSRR bandpass filter throughout pass-band range is below À18 dB, whereas out-band suppression is very high. The three-cascaded CSRR band-pass filter achieves better performance in the passband and obtains higher harmonic suppressions in the stop-band. MEASURED RESULTSTo validate the simulated analysis, two-cascaded and three-cascaded CSRR band-pass filters are designed and fabricated. Figure 6 shows the photograph of two band-pass filters with a substrate of ROGERS 4350B. The measured results of two bandpass filters are showed in Figure 7. Measured results show that: the return loss of two-cascaded CSRR band-pass filter is below À10 dB from 4.61 to 5.50 GHz, while the insertion loss in the stop-band is better than 20 dB; the return loss of three-cascaded CSRR band-pass filter is below À18 dB from 4.81 to 5.44 GHz, while the insertion loss is big in the stop-band. The measured results also show the out-band suppression of the three-cascaded CSRR band-pass filter is high and the pass-band performance of the three-cascaded CSRR band-pass filter is excellent. The measured results almost comply with the simulated results and only a small frequency offset and a different insertion loss is due to fabrication tolerance. CONCLUSIONSIn this article, band-pass filters using CSRR are proposed. Twocascaded and three-cascaded CSRR band-pass filters are designed, fabricated and measured. The measured results have shown good agreement with the simulated results. Two-cascaded and three-cascaded CSRR band-pass filters have advantages of compact size, low insertion loss, excellent pass-band performance, and high out-band suppression. This structure can be also used in diplexer and other microwave devices.ABSTRACT: We report the heterodyne generation of a narrow radiofrequency carrier by the beat of the signal of a bimodal fiber laser. The bimodal operation of the designed multiple-cavities-filter-based laser is presented, as well as the measured narrow microwave tone, suitable for modern microwave photonics links. V C 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:451-454, 2012; View this article online at wileyonlinelibrary.com.

An opto‐electronic oscillator based on Fabry‐Perot stabilized dual‐wavelength fiber ring laser

“…We employ a fiber ring laser configuration very similar to that reported in Reference8 but with a mutual coupling from an OEO loop. It was shown that the present configuration was able to narrowing the microwave FWHM linewidth by 84.1% when compared with that reported in Reference8. Note that the phase‐noise of −100 dBc/Hz @10 kHz is very close to that achieved by OEO architectures that do not use kilometer‐long fibers and have high integrability 17,18 …”

“…This is accomplished in a ring topology, where an erbium‐doped fiber amplifier (EDFA) act as a broadband light source while a second optical amplifier works as a gain media. A similar DWFRL experimental configuration has been reported in Reference8, but without the opto‐electronic oscillator (OEO) feedback loop. When compared with Reference8, the present novel setup allows a linewidth reduction of ~84.1% at full width at half maximum (FWHM) of the microwave carrier generated from the beat of the optical signals.…”

“…When compared with Reference8, the present novel setup allows a linewidth reduction of ~84.1% at full width at half maximum (FWHM) of the microwave carrier generated from the beat of the optical signals. While a number of works already reported dual‐wavelength operation 8–10 or opto‐electronic‐oscillation, 11–18 the present paper reports the simultaneous employment of both technologies named as dual‐wavelength fiber ring laser mutual‐coupled to an opto‐electronic oscillator (2‐λ‐OEO) in order to generate a narrow linewidth microwave carrier with a high extinction ratio and low phase‐noise.…”

A multi‐cavity fiber‐optic device for refractive index measurement

“…An arrangement of two similar in‐tandem FBGs gives origin to an all‐fiber FP cavity with narrow transmittance peaks appearing patterned inside the resonance band of the FBGs . The main FP cavity of the proposed sensor is obtained by placing two similar FBGs spaced by a physical distance from each other, as depicted in Figure (a), the FBGs acting as spectrally‐selective partially‐reflective mirrors.…”

Sensitivity and stability characterization of linear cavity erbium‐doped fiber laser for pressure measurement

“…Optical fiber sensing can deliver numerous key advantages over conventional, electronic sensing technologies for design validation, process optimization, and condition monitoring. The development in the field of fiber laser over the past years has been very aggressive with number of reports being published on new configuration and setting that has improved the performance of the fiber laser in term of new configuration and setting to produce higher output power, larger tuning range, and more output lasing channels [1–5]. This has attracted many researchers to find ways to develop a new application that will fully use the performance of the fiber laser.…”