Silicon Photonics for Radiation Resilient Systems

Silicon photonics offers a platform for integrating optical functionality—such as modulation, detection and routing of light—directly onto silicon substrates using processes compatible with large-scale microelectronics. This convergence promises low-mass, compact and energy-efficient solutions for data transmission and sensing in environments subject to high levels of ionising and non-ionising radiation. In applications ranging from deep-space probes and satellite communications to high-energy physics detectors and nuclear reactors, devices must tolerate total-ionizing doses in the megagray range, displacement damage from neutrons or protons, and single-event effects. Strategies to enhance resilience include optimised device geometries, high-doping concentrations, specialised passivation layers, enclosed-layout transistor designs, thermal annealing and cryogenic operation. Progress in both active components (modulators, photodiodes) and passive structures (waveguides, micro-ring resonators) has steadily increased radiation thresholds while preserving high data rates and low optical loss. This field unites materials science, device engineering and circuit design to address global challenges in space exploration, scientific instrumentation and secure communications.

Research from Nature Portfolio

One foundational investigation examined the effects of γ-ray irradiation up to 1 MGy on passivated silicon photonic devices. It demonstrated that devices featuring robust surface passivation and standard silicon-on-insulator waveguides exhibited negligible degradation in optical transmission and modulation behaviour even after extreme total-ionizing doses. The study confirmed that careful control of the interface chemistry and minimisation of oxide charge trapping are key to maintaining stable refractive indices and loss figures. These findings provide a benchmark for subsequent efforts to develop radiation-hard integrated photonic circuits for harsh environments.

Silicon Photonics for Radiation Resilient Systems publication trend

The graph below shows the total number of articles in silicon photonics for radiation resilient systems across all publications each year (not limited to Nature Index journals).

Technical terms

Silicon photonics: Integration of optical waveguides, modulators and photodetectors on silicon-on-insulator substrates using standard CMOS-compatible processes.

Mach–Zehnder modulator (MZM): An interferometric device that encodes data onto light by varying the relative phase between two arms of a waveguide interferometer.

Ring resonator: A curved waveguide that supports resonant optical modes, used for filtering, sensing or modulation by tuning its effective refractive index.

Total-ionizing dose (TID): The cumulative energy deposited in a material by ionising radiation, typically expressed in grays (Gy), which can induce trapped charges and oxide degradation.

Displacement damage: Defects introduced in the crystal lattice by high-energy particles, leading to scattering centres that increase optical loss or alter carrier lifetimes.

References

1. Assessing Radiation Hardness of Silicon Photonic Sensors. Scientific Reports (2018).
2. A 10 Gb/s Line Driver in 65 nm CMOS Technology for Radiation-Pervaded and High-Temperature Applications. IEEE Access (2023).
3. Ionizing Radiation Effects in Silicon Photonics Modulators. IEEE Transactions on Nuclear Science (2022).
4. High energy irradiation effects on silicon photonic passive devices.. Optics Express (2022).