40 GHz high-efficiency Michelson interferometer modulator on a silicon-rich nitride and thin-film lithium niobate hybrid platform

Abstract

We propose and demonstrate a Michelson interferometer modulator with integrated Bragg reflectors on a silicon-rich nitride–thin-film lithium niobate hybrid platform. High-reflectivity Bragg reflectors are placed at the ends of both arms, which double the electro-optic (E-O) interaction length and reduce the velocity mismatch between the microwave and optical wave. The presented Michelson interferometer modulator achieves a measured half-wave voltage length product as low as 1.06 V cm and high-speed modulation up to 70 Gbps. A 3-dB E-O bandwidth beyond 40 GHz is also achieved, which is, to the best of our knowledge, the highest modulation bandwidth of Michelson interferometer modulators.

Thin-Film Lithium Niobate Based Acousto-Optic Modulation Working at Higher-Order TE1 Mode

“…We find that the use of the higher-order TE 1 mode reduces the key modulation parameter V π L for the proposed AOM. The minimum value V π L is ~0.0084 V•cm, which is obviously lower than previous reports [25][26][27][28][29]. Figure 7 shows the refractive index change ∆n tot of the waveguide versus the slant angle of the TFLN waveguide sidewall.…”

“…The photo-elastic effect, moving boundary effect, and electro-optic effect were all included in the analysis of the AOI effect. The key V π L is reduced to less than 0.01 V•cm, which is superior to those AOMs working at the fundamental TE 0 mode and other EOMs, (e.g., V π L > 0.04 V•cm for AOM, V π L > 1 V•cm for EOM) [25][26][27][28][29]. Moreover, the metal absorption loss of the proposed AOM is quite low, since the key modulation electrodes of the AOM do not need to be placed close to the optical waveguide, while close electrode placement to the optical waveguide is necessary for EOM.…”

“…Note that such an ultra-low V π L value is quite useful for on-chip low power and low-loss modulation. Such performance cannot be easily achieved by current TFLN-based EOMs (best value ~1.0 V•cm [27][28][29]). For the EOMs, the modulation electrodes need to be placed as close to the optical waveguide as possible in order to effectively reduce the driving voltage, at the cost of increased metal absorption loss.…”

Advances in lithium niobate photonics: development status and perspectives

“…Subsequently, with the high-quality TFLN that is now commercially available, various kinds of modulators have been demonstrated. 31,52,88,[241][242][243][272][273][274][275][276][277][278][279][280][281][282][283][284][285][286][287][288] Some of the reported modulators in LN platforms are summarized in Table 5.…”

Recent advances in integrated optical directed logic operations for high performance optical computing: a review

“…Other important combinational DL devices, including the comparator [80][81][82], parity checker [83], and Feynman gate [84] were also demonstrated with relatively low working speed for proofs of concepts in recent years. To achieve higher operational speeds, one can employ other advanced modulation schemes, such as the plasma dispersion effect [85,86], graphene-based Fermi level modulation [87][88][89], or lithium niobate waveguide [90][91][92] to modulate the MRRs.…”