How Does a Photonic Chip Work

Optical communication has long promised higher bandwidth and lower power consumption than electrical interconnects, but the practical challenge lies in integrating optical functions onto a compact, manufacturable chip. A photonic chip—sometimes called a photonic integrated circuit (PIC)—manipulates light instead of electrons, using waveguides, modulators, splitters, and photodetectors to generate, process, and detect optical signals. For high-speed applications such as data center interconnects and telecom networks, the performance of these chips hinges on the electro-optic material platform. Among the most advanced solutions today are TFLN chips (thin-film lithium niobate), which combine exceptional linearity, wide bandwidth, and low loss. To understand how a photonic chip works, we need to look at its core building blocks and how they handle signals from the electrical domain to the optical domain and back.

Guiding and Modulating Light at High Speed

At the heart of any photonic chip is the optical waveguide—a microscopic structure that confines light and directs it along a prescribed path. In TFLN chips, waveguides are etched into a thin layer of lithium niobate, a material known for its strong electro-optic effect. When an electrical voltage is applied, the refractive index of the waveguide changes, altering the phase of the light passing through. This principle enables the Mach–Zehnder modulator (MZM), a fundamental component that converts high-speed electrical signals into modulated optical carriers. Our chips achieve a 3‑dB bandwidth of 110 GHz and a differential half‑wave voltage below 1.5 V, meaning they can encode data at 3.2T per module (DR8 configuration) with very low power consumption. The ability to support both differential and single‑ended drive signals gives system designers flexibility while maintaining extinction ratios above 25 dB—critical for low‑bit-error‑rate transmission.

From Low Loss to High Integration

Another essential aspect of how a photonic chip works is managing optical losses. Every bend, split, and coupling interface can waste signal power, reducing reach and increasing laser requirements. Our TFLN chips keep insertion loss below 14 dB, including fiber-to-chip coupling loss, which is remarkably low for such wide‑bandwidth devices. This efficiency stems from two factors: the intrinsic transparency of lithium niobate at telecom wavelengths, and our optimized edge‑coupling and waveguide designs. Beyond modulators, photonic chips can integrate arrayed waveguide gratings for wavelength multiplexing, variable optical attenuators, and photodetectors. However, for Terabit Ethernet and coherent links, the modulator’s performance often defines the entire system’s capability. With TFLN chips, we have demonstrated that a single continuous‑wave laser can drive multi‑channel 800G and 1.6T modules—a milestone in density and power efficiency.

Why This Matters for Your Optical Systems

Understanding how a photonic chip works helps explain why material choice is not an academic detail but a strategic decision. Traditional platforms like silicon or indium phosphide impose trade‑offs between bandwidth, linearity, and loss. TFLN chips break those trade‑offs, offering high linearity for coherent formats, low Vπ for CMOS‑compatible driver voltages, and a clear path to mass production. We have established design, fabrication, and packaging platforms capable of delivering these chips at scale. As we look to 3.2T and beyond, the fundamentals remain the same: guide light, modulate it efficiently, and keep losses low. TFLN chips excel at every step.

At Liobate, we are committed to providing superior photonic chips that empower your next‑generation optical modules and systems. Whether your focus is data centers, telecom networks, test instruments, or automotive LiDAR, we invite you to explore how our TFLN platform can turn optical challenges into capabilities. Let’s build the photonic future together.