Optical Scattering Induced Noise in Fiber Ring Resonators and Optoelectronic Oscillators

Abstract

14 pagesInternational audienceThis paper reports both theoretical and experimental studies on nonlinear optical phenomena generated at very low thresholds in fiber ring resonators featuring ultra-high quality factors. These studies are focused on two optical scattering phenomena: the Rayleigh and the Brillouin scatterings. The effects of these scattering phenomena on the phase noise of an optoelectronic oscillator based on the fiber ring resonator are detailed. A 30 dB reduction in the oscillator phase noise at 10 Hz offset frequency has been demonstrated by limiting the nonlinear scattering effects when using low input optical power. Moreover, a new high quality factor fiber ring resonator, optimized and immunized against some of these nonlinear optical effects, has been designed and an oscillator phase noise level of -50 dBc/Hz at 10 Hz offset frequency has been achieved

Fiber ring resonators with Q factors in excess of 10¹⁰ for time and frequency applications

“…Optical resonators with Q factor in excess of 10 10 have been successfully designed and realized using the fiber ring resonator approach. The stabilization of a laser on one resonance has been demonstrated, using the Pound Drever Hall technique.…”

“…With this approach, most of our designs were based on 20 m fiber rings, featuring Q factors of about 3 10 These resonators have been used to stabilize various OEOs. All the OEOs have the same topology, which is described in previously published papers [7,10] and depicted in Figure 2. The laser is first locked to the resonator frequency thanks to a Pound Drever Hall (PDH) feedback loop ; the oscillation is started thanks to a second loop which is a microwave loop including one or two amplifiers, a phase shifter and a dielectric resonator filter centered at 10.2 GHz.…”

“…These FRRs are compact and easy to use. However, their high quality factor, combined with significant intra-cavity power enhancement factor, lead to the generation of nonlinear optical effects inside the resonator, especially Rayleigh and Brillouin scattering [10]. When the FRR is used to stabilize the frequency of an optoelectronic oscillator (OEO), these nonlinear optical effects degrade the OEO phase noise.…”

Nonlinear refractive index measurement utilizing bistable behavior of double coupling optical fiber ring resonator

“…Bistability commonly refers to a state in which the output intensity of a device may take two different values for the same input intensity depending on the initial conditions [2]. Optical bistabiltiy has been studied widely over the past years, and numberous applications such as differential amplification, optical thresholding, or all-optical switching have been demonstrated [3][4][5][6]. This interesting behavior originates in an optical Kerr effect that the refractive index of an optical fiber is changed depending on the optical intensity.…”

Radio frequency spectral characterization and model parameters extraction of high Q optical resonators

“…Many different resonator technologies can be involved in these applications, with some of which featuring a ultra-high Q factors, such as: Ultra Low Expansion (ULE) Fabry-Perot resonators9 ( Q  ~ 10 10 ), Whispering Gallery Modes (WGM) resonators, e.g. silica spheres10 ( Q  ~ 10 9 ) or polished monocrystalline disks11 ( Q  ~ 10 8 to 10 10 ), active or passive fiber ring resonator12 ( Q  ~ 10 8 to 10 10 ). Therefore, a detailed knowledge of their properties is essential to accurately model these devices and thus to achieve better performance.…”