Inducing and harnessing stimulated Brillouin scattering in photonic integrated circuits

Abstract

Doc. ID 195152) We review recent progress in inducing and harnessing stimulated Brillouin scattering (SBS) in integrated photonic circuits. Exciting SBS in a chip-scale device is challenging due to the stringent requirements on materials and device geometry. We discuss these requirements, which include material parameters, such as optical refractive index and acoustic velocity, and device properties, such as acousto-optic confinement. Recent work on SBS in nano-photonic waveguides and micro-resonators is presented, with special attention paid to photonic integration of applications such as narrow-linewidth lasers, slowand fast-light, microwave signal processing, Brillouin dynamic gratings, and nonreciprocal devices.

Phonon-Limited-Linewidth of Brillouin Lasers at Cryogenic Temperatures

“…Power fluctuation resulting from thermal phonons has also been studied in fiber-optic SBS Stokes wave generation [10], and the intensity and phase noise have been measured in narrow-linewidth Brillouin lasers [11]. More recently, the SBS process has attracted considerable interest in microscale and nanoscale devices [12]. Brillouin laser action has been demonstrated in several microcavity resonator systems including silica [13][14][15][16], CaF 2 [17], and silicon [18], and Brillouin amplification has been demonstrated in integrated chalcogenide waveguides [19].…”

Invited Article: Acousto-optic finite-difference frequency-domain algorithm for first-principles simulations of on-chip acousto-optic devices

“…In a backwards SBS gain process, one typically considers the interaction of three modes: a backward-propagating optical pump E 2 at ω 2 with propagation constant β 2 , a forward optical Stokes wave E 1 at ω 1 with propagation constant β 1 , and an acoustic wave U = U xx + U yŷ at frequency Ω = ω 2 − ω 1 and wave vector q = β 2 − β 1 . [1][2][3][4] Upon the generation of and the mixing with the acoustic wave, the Stokes wave experiences exponential growth along its propagation direction. To maximize the gain of the Stokes field, given the generated acoustic wave vector q, the frequency of a generated acoustic wave Ω must be approximately equal to the frequency of an acoustic guided mode of the waveguide at this wavevector q, as denoted by Ω B .…”

“…[1][2][3][4] As SBS yields an extremely strong nonlinear interaction with narrow resonances, it has found applications in many important areas of optics and acoustics. [1][2][3] Traditionally, SBS has been studied extensively in fiber-optic devices in order to inhibit undesired nonlinear effects induced by SBS.…”

“…[1][2][3] Traditionally, SBS has been studied extensively in fiber-optic devices in order to inhibit undesired nonlinear effects induced by SBS. [1][2][3][4] More recently, SBS has been tailored for micron-scale on-chip devices, 2,3,[5][6][7][8][9][10] where it is considered to be an attractive candidate in the creation of lasers with ultra-narrow bandwidths, [11][12][13][14] gigahertz frequency combs, 15,16 slow light, 17 and on-chip signal processing devices such as the microwave photonic filter 18,19 and optical isolators. [20][21][22][23] Given the wide range of devices that can harness SBS, it is important to develop general numerical techniques that can facilitate the device design process.…”

Bandwidth tunability of stimulated Brillouin scattering based microwave photonic filter

“…The ability to obtain widely continuous tunability together with very high-resolution filtering has been a long-term aim that has attracted a lot of attentions and investigations including the fiber [3] and integrated waveguide [4] based MPFs. With the unique features of narrowband and relatively low optical power threshold, the stimulated Brillouin scattering (SBS) in the optical fiber [5] has been exploited to achieve the wide continuously tunable and high-resolution filtering.…”