Tunable dual-channel ultra-narrowband Bragg grating filter on thin-film lithium niobate

Abstract

We demonstrate dual-channel phase-shifted Bragg grating filters in the telecom band on thin-film lithium niobate. These integrated tunable ultra-narrow linewidth filters are crucial components for optical communication and sensing systems, as well as future quantum-photonic applications. Thin-film lithium niobate is an emerging platform suitable for these applications and has been exploited in this Letter. The demonstrated device has an extinction ratio of 27 dB and two channels with close linewidths of about 19 pm (quality factor of 8 × 10 4 ), separated by 19 GHz. The central wavelength could be efficiently tuned using the high electro-optic effect in lithium niobate with a tuning factor of 3.83 pm/V. This demonstration can be extended to tunable filters with multiple channels, along with desired frequency separations and optimized tunability, which would be useful for a variety of complex photonic integrated circuits.

Silicon-on-Insulator Microwave Photonic Filter With Widely Tunable and Reconfigurable Flat-Top Bandpass Functionality

“…This value is in accordance with those previously reported for SiP modulators, for which the system linearity is mainly limited by the physics of the plasma dispersion effect in the carrier-depletion based device [45]. The SFDR could be for instance improved by implementing the PIC using the lithiumniobate-on-insulator (LNOI) technological platform, where linear Pockels-based EO modulation mechanism is available for realizing high-speed efficient phase modulators [46], and waveguide Bragg grating filters have also been recently demonstrated [47], [48].…”

Performance Analysis of Millimeter-Wave Optic Modulators in Thin-Film Lithium Niobate

“…An electro-optic modulator with a broad bandwidth covering the entire mmWave range is vital of such a system. Importantly, the peripheral components, including antennas [3], lasers [24], optical filters [21,22], amplifiers [24,25] and delay lines [23], have all been demonstrated on the LN platform and could potentially allow the integration of this entire system on the same chip.…”

“…As a result, a number of high-performance TFLN modulators have been developed, demonstrating low half-wave voltages (Vπ) [10,11], high modulation bandwidths around 100 GHz [12][13][14][15][16][17], as well as ultrahigh linearity [18]. The high-performance TFLN modulators could potentially be further integrated with frequency comb sources [19,20], tunable filters [21,22] and low-loss delay lines [23] on the same platform for future microwave-and mmWave-photonic applications. While many of these demonstrated modulators have theoretically predicted modulation capabilities much beyond 100 GHz [14][15][16], the experimental demonstrations are limited.…”

Advances in lithium niobate photonics: development status and perspectives

“…In addition, mode-related devices, 131,244,250,251,255,261,262,267 TO-based devices, [85][86][87] Bragg grating filters, 253,256,257,264 optical true delay lines, 263 and optical phased arrays 260 have also been demonstrated in the LN platform. Most of them rely on the large refractive index contrast available in TFLN.…”