Broadband tunable electro-optic switch/power divider as potential building blocks in integrated lithium niobate photonics

Abstract

We demonstrate an electro-optic (EO) switch or in general, an EO controllable power divider based on a periodically poled lithium niobate (PPLN) polarization mode converter (PMC) and a five-waveguide adiabatic coupler integrated on a Ti:LN photonic circuit chip. In this integrated photonic circuit (IPC) device, the PPLN works as an EO controllable polarization rotator (and therefore a PMC), while the adiabatic coupler functions as a broadband polarization beam splitter (PBS). The 1-cm long PPLN EO PMC of the IPC device is characterized to have a half-wave (or switching) voltage of Vπ∼20 V and a conversion bandwidth of ∼2.6 nm. The splitting ratios of the adiabatic coupler PBS in the IPC device are >99% for both polarization modes over a broad spectral range from 1500–1640 nm. The EO mode of the implemented IPC device is activated when the PPLN EO PMC section is driven by an external voltage; the characterized EO switching/power division behavior of the device is in good agreement with the theoretical fit. The tunability of the EO IPC device in the 100-nm experimental spectral range is also demonstrated via the temperature tuning. The featured broad tunability and high integrability of the EO device presented in this study facilitates it to be an advantageous building block for realizing an on-chip photonic system.

High-performance electro-optic switches with compact multimode interference and Bezier S-bend waveguides

“…Furthermore, we precisely set the control parameter to the applied voltage (V) to finely control the switch behavior. We then calculate the half-wave voltage (V π ), a vital parameter for investigating the efficiency of the EO switch [36]. V π represents the required voltage to change the phase by π radians.…”

“…V π represents the required voltage to change the phase by π radians. Its value is determined by a combination of factors, notably influenced by the design of optical components and electrodes [7,[33][34][35][36]. In the absence of applied voltage, the light remains confined within the bar port of the switch.…”

Compact asymmetric multimode interference coupler-based Electro-optic switches with Bezier S-bend waveguides

“…Essential for maximizing the efficiency of the EO switch are vital parameters, including the half-wave voltage (Vπ) [36]. This parameter plays a critical role in achieving effective switching.…”

“…Vπ signifies the voltage necessary for a phase change of π radians. Its value is determined by a combination of factors, with a notable influence from the design of the optical components and electrodes (VπL) [36,37]. The switch's operational dynamics are contingent on This results in an output intensity of about 0.40±0.02 a.u.…”