Precision electronics support for photonic systems: The key role of device selection in high-performance design

23 April 2025

Precision electronics support for photonic systems: The key role of device selection in high-performance design

With the rapid development of high-performance photonic systems, from communications and imaging to sensing and quantum information processing, electronic components' accuracy, response speed, and signal integrity are becoming key factors affecting system performance. Traditionally, photonics has emphasized the performance of light sources, waveguides, and detectors. Still, with the increasing degree of integration, the electronic systems surrounding these optical devices, especially signal conditioning, power management, and timing control circuits, are bearing unprecedented technical pressure.

In this context, mainstream optical platforms such as silicon photonics (SiPh) and integrated photonic chips are accelerating the development of electronic-photonic co-design. Whether it is an on-chip modulator driver, a transimpedance amplifier (TIA), or a high-precision clock distribution circuit, the quality of the components behind it directly determines the system stability and signal fidelity.

How does device accuracy affect system performance?

Taking the optical communication system based on Mach-Zehnder modulator as an example, in order to achieve high-speed data transmission above 40 Gbps, it must be equipped with a driver circuit with a response time of less than 25 ps and a bandwidth of more than 20 GHz. In actual design, such high-speed signal channels often rely on key components such as Skyworks' SKY85726-11 high-speed amplifier and ADI's HMC858LC5 adjustable limiting amplifier.

In high-speed signal paths, engineering teams usually select alternative models with equivalent performance and screen them with package compatibility to meet signal integrity requirements. For example, TI's THS4304 high-speed operational amplifier, with a gain-bandwidth product of 2.4 GHz, can be used for signal amplification before laser modulation and is suitable for precision interferometry and modulation transmission systems.

Not only high speed but low noise is also a core indicator. In the avalanche photodiode (APD) receiving system, the input electrical noise density of the transimpedance amplifier must be less than 2 pA/√Hz to meet the requirements of weak light signal reception. For example, Maxim Integrated's MAX40660 TIA provides a typical low noise performance of 1.6 pA/√Hz and has wide temperature stability, which is suitable for industrial and scientific research optical detection platforms.

Device Challenges in Multi-Channel Optical Interferometry Systems

The 8-channel parallel interference system needs to solve the channel consistency problem, requiring input offset voltage <50 μV and noise density ≤10 nV/√Hz. Using a low-noise instrumentation amplifier with an input bias current of 0.5 nA and a common-mode rejection ratio of 120 dB, the channel gain deviation can be reduced to less than 0.02%, and the interference fringe signal-to-noise ratio can be improved by 32%. Laser trimming of the resistor network controls the temperature drift coefficient within 5 ppm/℃, ensuring phase stability from -40℃ to 85℃.

During hardware iteration, if package compatibility issues are encountered, pin-equivalent devices with a setup time of ≤3 μs and a power supply rejection ratio of >85 dB can be selected, and the 14-day verification cycle can be shortened without modifying the design. This strategy is based on 23 parameter verifications (including 0.8% impedance tolerance) to support the agile development of high-precision optical systems.

Technology Trend: Electronic-Photonic Co-design Promotes Device Upgrade

As photonic systems move towards higher levels of integration, "Co-Packaged Optics" (CPO) technology has become a key development direction for multiple optical communications and high-performance computing systems. In CPO modules, modulator drivers and TIAs are often packaged together with optical chips, which places higher demands on electronic components' miniaturization, thermal stability, and signal integrity.

Current mainstream design trends include:

• Low parasitic packaging: High-speed amplifier and PLL chips in LGA/BGA micro-packages to reduce reflections and mismatches in the signal path;
• Wide temperature range device selection: Especially in drones and field sensing platforms, components that require stable operation from -40°C to 125°C are becoming increasingly common;
• High-stability clock distribution: Timing circuits in spectrometers and interferometer systems rely on low-jitter clocks, such as SiTime's SiT5356 series, which has RMS jitter as low as 80 fs, suitable for high-speed ADC driving.

Achieving these technological breakthroughs requires full-chain support from device selection, parameter verification to mass production assurance, including a multi-dimensional device database, a dynamic BOM risk warning system, and a full-temperature parameter feature library (including -55°C~150°C characteristic curves). This technical ecosystem support capability enables companies to quickly build pluggable optical modules that meet the ITU-T G.698.4 standard and shorten the development cycle by more than 40%.

Addressing real challenges in the industry: supply chain uncertainty and verification needs

Photonic technology has fast iterations and long verification cycles, while component supply is frequently affected by the macro market and geopolitics. Against this backdrop, the industry is exploring more flexible and reliable supply models to meet multi-stage needs from solution verification to mass deployment. Currently, distributors are gradually optimizing product availability and delivery mechanisms, and improving their support capabilities for various corporate entities and diversified procurement situations. By building a diversified product system, improving inventory transparency, and promoting information linkage between the design and procurement ends, the supply chain response speed and system adaptation efficiency are continuing to improve.

With the booming development of integrated photonics technology, the role of electronic systems and components is no longer just "auxiliary support", but an integral part of the overall design. As an important participant in the global electronic component distribution network , WIN SOURCE provides a variety of device options and information interfaces to support more efficient collaboration between design and supply chain.

Reprinted from WIN SOURCE ELECTRONIC-NEWS

© 2025 Win Source Electronics. All rights reserved. This content is protected by copyright and may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of Win Source Electronics.