Tunable hybrid silicon nitride and thin-film lithium niobate electro-optic microresonator

Abstract

This Letter presents, to the best of our knowledge, the first hybrid Si 3 N 4 -LiNbO 3 -based tunable microring resonator where the waveguide is formed by loading a Si 3 N 4 strip on an electro-optic (EO) material of X -cut thin-film LiNbO 3 . The developed hybrid Si 3 N 4 -LiNbO 3 microring exhibits a high intrinsic quality factor of 1.85 × 10 5 , with a ring propagation loss of 0.32 dB/cm, resulting in a spectral linewidth of 13 pm, and a resonance extinction ratio of ∼27 dB within the optical C-band for the transverse electric mode. Using the EO effect of LiNbO 3 , a 1.78 pm/V resonance tunability near 1550 nm wavelength is demonstrated.

Rejuvenating a Versatile Photonic Material: Thin‐Film Lithium Niobate

“…One of the main advantages of this method is the ease of processing. Several materials have been pursued in this regard, such as tantalum pentoxide (Ta 2 O 5 ), [29] chalcogenide glass (ChG), [70] silicon nitride (SiN, Si 3 N 4 ), [41,71,72,81,85,100,101,124] and titanium dioxide (TiO 2 ), [40] with reported propagation loss values as low as ∼1 dB cm −1 for plasma-enhanced chemical-vapor deposition Figure 3a), [71] dry-etched ( Figure 3b), [75,78] and SOI-bonded ( Figure 3d) [76,77,80,84] methods, while for nonlinear devices, rib-loaded [100,101] and dry-etched [102,105] have been the most commonly employed platforms. In comparison to platforms (a)-(c), platform (d) requires additional bonding and TFLN substrate removal steps.…”

“…In recent years, based on this rapidly-growing technology, a plethora of ultracompact integrated photonic devices and circuits, such as microdisk [59][60][61][62] and microring [46,[63][64][65][66] resonators, EO modulators, [67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84][85] acousto-optic modulators, [86][87][88][89] photodetector, [90] integrated single-photon detector, [91] grating couplers, [92][93][94][95][96] fiber-to-chip edge couplers, [97][98][99] wavelength Figure 2. Summary of the steps for fabrication of TFLN on Si wafers.…”

Microstructure and domain engineering of lithium niobate crystal films for integrated photonic applications

“…Furthermore, a tunable hybrid Si 3 N 4 -LN microring resonator (Fig. 6b) 72 and a racetrack resonator (Fig. 6c) 73 were lithographically deposited on an x-cut LNOI platform with a resonance tunability of up to 1.78 and 2.9 pm V −1 , respectively.…”

Review of Recent Progress on Silicon Nitride-Based Photonic Integrated Circuits

“…The Si3N4 platform alone and with III-V material has broadly been used for the polarization rotation and modulators [51][52][53][54][55], resonators and photodetectors [56][57][58][59][60][61][62][63][64][65], grating couplers [66][67][68][69][70], sensing applications [71][72][73][74], highperformance lasers on-chip, delay lines, optical filters, and optical frequency comb generation [75][76]polarization beam splitters and couplers [77][78][79][80]. The foundries all over the world, such as CEA-Leti, AIM photonics, ST microelectronics, and others have announced Si photonics as a platform that integrates Si3N4 waveguide layer onto Si waveguides for various applications [81][82][83][84][85][86][87].As the world is moving towards the high signal bandwidth and data rate, Si3N4 waveguide technology with SOI and III-V platform has recently opened up the new quarters for on-chip applications.…”