Coupled Dual-Loop Optoelectronic Oscillator Based on Stimulated Brillouin Scattering

Feng Fan,Xiuyou Han,Jingjing Hu,Yiying Gu,Jiabin Wang,Zhenlin Wu,Wenwu Zhu,Mingshan Zhao

doi:10.3390/app9102077

Abstract

A tunable optoelectronic oscillator (TOEO) with coupled dual-loop (CDL) based on stimulated Brillouin scattering (SBS) is proposed. In our scheme, the CDL is constructed by cascading a dual-output Mach–Zehnder intensity modulator (DOMZM) and a single output Mach–Zehnder intensity modulator (MZM). One optical output of the DOMZM is directly injected to the MZM, and the other optical output of the DOMZM is transformed into microwave signals to modulate the MZM. The narrow gain spectrum of SBS is used to select the oscillation frequency and realize frequency tunability. By joining the CDL, we can not only increase side mode suppression ratio (SMSR) and decrease phase noise, but also improve stability of the TOEO. Experimental results show that microwave signals from 2 GHz to 18 GHz with the SMSR as high as 60 dB and the phase noise as low as −95 dBc/Hz at 10 kHz frequency offset are achieved. Furthermore, the frequency drift is less than 0.3 ppm and the power drift is lower than 0.2 dB at 10 GHz within 30 min in lab condition.

Highlights

An optoelectronic oscillator (OEO) as a new type of microwave signal source, can generate high-quality microwave signals of tens or even hundreds of GHz [1]
tunable optoelectronic oscillator (TOEO) consists of a signal laser (SL), a dual-output Mach–Zehnder intensity modulator (DOMZM), a
The2019, schematic diagram of the coupled dual-loop stimulated Brillouin scattering (SBS)-based TOEO is shown in Figure 1a.3 of TOEO consists of a signal laser (SL), a dual-output Mach–Zehnder intensity modulator (DOMZM), a single-mode fiber(SMF), (SMF), photodetectors single Mach–Zehnder output Mach–Zehnder intensity single-mode fiber twotwo photodetectors (PD), (PD), a singlea output intensity modulator modulator (MZM), an optical isolator (ISO), a polarization controller (PC), an optical circulator (MZM), an optical isolator (ISO), a polarization controller (PC), an optical circulator (OC), a(OC), high anon-linear high non-linear fiber (HNLF), two electrical amplifier (EA), an electrical splitter (ES)

Summary

Introduction

An optoelectronic oscillator (OEO) as a new type of microwave signal source, can generate high-quality microwave signals of tens or even hundreds of GHz [1]. In order to generate frequency tunable microwave signals, many tunable optoelectronic oscillator (TOEO) schemes have been proposed [5,6,7,8]. In [5], the MPBF is formed by an injection-locked Fabry–Perot laser diode (FP-LD) that realizes frequency tuning by adjusting the cavity length or the wavelength of the incident light This solution enables microwave signal generation with a frequency tuning range of 6.41 to 10.85 GHz. the stability of the microwave signals generated by the FP-LD are poor. A stability improved SBS-based TOEO has been designed in [22], and the maximum power and frequency drift at 10.69 GHz are about 1.4 dB and 1 ppm in the case of testing for 1000 s. 10 kHz offset, and effectively avoid frequency hopping or multi-mode oscillation

Principle of Operation

Experiment and Results

The 10 almost

Conclusions